* Re: [RFC][PATCH v2] ima: Add support for staging measurements for deletion and trimming
From: steven chen @ 2026-01-28 21:30 UTC (permalink / raw)
To: Roberto Sassu, corbet, zohar, dmitry.kasatkin, eric.snowberg,
paul, jmorris, serge
Cc: linux-doc, linux-kernel, linux-integrity, linux-security-module,
gregorylumen, nramas, Roberto Sassu, steven chen
In-Reply-To: <20251212171932.316676-1-roberto.sassu@huaweicloud.com>
On 12/12/2025 9:19 AM, Roberto Sassu wrote:
> From: Roberto Sassu <roberto.sassu@huawei.com>
>
> Introduce the ability of staging the entire (or a portion of the) IMA
> measurement list for deletion. Staging means moving the current content of
> the measurement list to a separate location, and allowing users to read and
> delete it. This causes the measurement list to be atomically truncated
> before new measurements can be added. Staging can be done only once at a
> time. In the event of kexec(), staging is reverted and staged entries will
> be carried over to the new kernel.
>
> User space is responsible to concatenate the staged IMA measurements list
> portions following the temporal order in which the operations were done,
> together with the current measurement list. Then, it can send the collected
> data to the remote verifiers.
>
> Also introduce the ability of trimming N measurements entries from the IMA
> measurements list, provided that user space has already read them. Trimming
> combines staging and deletion in one operation.
>
> The benefit of these solutions is the ability to free precious kernel
> memory, in exchange of delegating user space to reconstruct the full
> measurement list from the chunks. No trust needs to be given to user space,
> since the integrity of the measurement list is protected by the TPM.
>
> By default, staging/trimming the measurements list does not alter the hash
> table. When staging/trimming are done, IMA is still able to detect
> collisions on the staged and later deleted measurement entries, by keeping
> the entry digests (only template data are freed).
>
> However, since during the measurements list serialization only the SHA1
> digest is passed, and since there are no template data to recalculate the
> other digests from, the hash table is currently not populated with digests
> from staged/deleted entries after kexec().
>
> Introduce the new kernel option ima_flush_htable to decide whether or not
> the digests of staged measurement entries are flushed from the hash table.
>
> Then, introduce ascii_runtime_measurements_staged_<algo> and
> binary_runtime_measurement_staged_<algo> interfaces to stage/trim/delete
> the measurements. Use 'echo A > <IMA interface>' and
> 'echo D > <IMA interface>' to respectively stage and delete the entire
> measurements list. Use 'echo N > <IMA interface>', with N between 1 and
> LONG_MAX, to stage the selected portion of the measurements list, and
> 'echo -N > <IMA interface>' to trim N measurements entries.
>
> The ima_measure_users counter (protected by the ima_measure_lock mutex) has
> been introduced to protect access to the measurements list and the staged
> part. The open method of all the measurement interfaces has been extended
> to allow only one writer at a time or, in alternative, multiple readers.
> The write permission is used to stage/trim/delete the measurements, the
> read permission to read them. Write requires also the CAP_SYS_ADMIN
> capability.
>
> Finally, introduce and maintain dedicate counters for the number of
> measurement entries and binary size, for the current measurements list
> (BINARY_SIZE), for the current measurements list plus staged entries
> (BINARY_SIZE_STAGED) useful for kexec() segment allocation, and for the
> entire measurement list without staging/trimming (BINARY_SIZE_FULL) useful
> for the kexec-related critical data records.
Is the following possible race condition for staged list:
Agent A: create staged list Staged list A1
new measurement added Measurement list M1
Two lists in kernel: A1 and M1
Agent B: read staged list (A1) to do verification
new measurement added Measurement list M2
Two lists in kernel: A1 and M2
Agent A: verified and remove staged list (A1)
new measurement added Measurement list M3
One list in kernel: M3
Agent C: create staged list Staged list C1
new measurement added Measurement list M4
Two lists in kernel: C1 and M4
Agent B: remove staged list (?), C1 removed ---this will cause problem
new measurement added Measurement list M5
One list in kernel: M5
Agent C: try to remove staged list(?)
Possible solution?
Save the total number trimmed T or tag
Trim request sync this parameter to trim the staged list
Regards,
Steven
> Note: This code derives from the Alt-IMA Huawei project, and is being
> released under the dual license model (GPL-2.0 OR MIT).
>
> Link: https://github.com/linux-integrity/linux/issues/1
> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
> ---
> .../admin-guide/kernel-parameters.txt | 4 +
> security/integrity/ima/ima.h | 18 +-
> security/integrity/ima/ima_fs.c | 240 +++++++++++++++++-
> security/integrity/ima/ima_kexec.c | 42 ++-
> security/integrity/ima/ima_queue.c | 169 +++++++++++-
> 5 files changed, 439 insertions(+), 34 deletions(-)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 6c42061ca20e..e5f1e11bd0a2 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -2215,6 +2215,10 @@
> Use the canonical format for the binary runtime
> measurements, instead of host native format.
>
> + ima_flush_htable [IMA]
> + Flush the IMA hash table when staging for deletion or
> + trimming measurement entries.
> +
> ima_hash= [IMA]
> Format: { md5 | sha1 | rmd160 | sha256 | sha384
> | sha512 | ... }
> diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
> index e3d71d8d56e3..8a6be4284210 100644
> --- a/security/integrity/ima/ima.h
> +++ b/security/integrity/ima/ima.h
> @@ -28,6 +28,15 @@ enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_BINARY_NO_FIELD_LEN,
> IMA_SHOW_BINARY_OLD_STRING_FMT, IMA_SHOW_ASCII };
> enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8, TPM_PCR10 = 10 };
>
> +/*
> + * BINARY_SIZE: size of the current measurements list
> + * BINARY_SIZE_STAGED: size of current measurements list + staged entries
> + * BINARY_SIZE_FULL: size of measurements list since IMA initialization
> + */
> +enum binary_size_types {
> + BINARY_SIZE, BINARY_SIZE_STAGED, BINARY_SIZE_FULL, BINARY__LAST
> +};
> +
> /* digest size for IMA, fits SHA1 or MD5 */
> #define IMA_DIGEST_SIZE SHA1_DIGEST_SIZE
> #define IMA_EVENT_NAME_LEN_MAX 255
> @@ -117,6 +126,8 @@ struct ima_queue_entry {
> struct ima_template_entry *entry;
> };
> extern struct list_head ima_measurements; /* list of all measurements */
> +extern struct list_head ima_measurements_staged; /* list of staged meas. */
> +extern bool ima_measurements_staged_exist; /* If there are staged meas. */
>
> /* Some details preceding the binary serialized measurement list */
> struct ima_kexec_hdr {
> @@ -281,10 +292,12 @@ struct ima_template_desc *ima_template_desc_current(void);
> struct ima_template_desc *ima_template_desc_buf(void);
> struct ima_template_desc *lookup_template_desc(const char *name);
> bool ima_template_has_modsig(const struct ima_template_desc *ima_template);
> +int ima_queue_stage_trim(unsigned long req_value, bool trim);
> +int ima_queue_delete_staged_trimmed(bool staged_moved);
> int ima_restore_measurement_entry(struct ima_template_entry *entry);
> int ima_restore_measurement_list(loff_t bufsize, void *buf);
> int ima_measurements_show(struct seq_file *m, void *v);
> -unsigned long ima_get_binary_runtime_size(void);
> +unsigned long ima_get_binary_runtime_size(enum binary_size_types type);
> int ima_init_template(void);
> void ima_init_template_list(void);
> int __init ima_init_digests(void);
> @@ -298,11 +311,12 @@ int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event,
> extern spinlock_t ima_queue_lock;
>
> struct ima_h_table {
> - atomic_long_t len; /* number of stored measurements in the list */
> + atomic_long_t len[BINARY__LAST]; /* num of stored meas. in the list */
> atomic_long_t violations;
> struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
> };
> extern struct ima_h_table ima_htable;
> +extern struct mutex ima_extend_list_mutex;
>
> static inline unsigned int ima_hash_key(u8 *digest)
> {
> diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
> index 87045b09f120..a96f7c36b34a 100644
> --- a/security/integrity/ima/ima_fs.c
> +++ b/security/integrity/ima/ima_fs.c
> @@ -24,7 +24,18 @@
>
> #include "ima.h"
>
> +/*
> + * Requests:
> + * 'A\n': stage the entire measurements list
> + * '[1, LONG_MAX]\n' stage N measurements entries
> + * '-[1, LONG_MAX]\n' trim N measurements entries
> + * 'D\n': delete staged measurements
> + */
> +#define STAGED_REQ_LENGTH 21
> +
> static DEFINE_MUTEX(ima_write_mutex);
> +static DEFINE_MUTEX(ima_measure_lock);
> +static long ima_measure_users;
>
> bool ima_canonical_fmt;
> static int __init default_canonical_fmt_setup(char *str)
> @@ -64,7 +75,8 @@ static ssize_t ima_show_measurements_count(struct file *filp,
> char __user *buf,
> size_t count, loff_t *ppos)
> {
> - return ima_show_htable_value(buf, count, ppos, &ima_htable.len);
> + return ima_show_htable_value(buf, count, ppos,
> + &ima_htable.len[BINARY_SIZE]);
>
> }
>
> @@ -74,14 +86,15 @@ static const struct file_operations ima_measurements_count_ops = {
> };
>
> /* returns pointer to hlist_node */
> -static void *ima_measurements_start(struct seq_file *m, loff_t *pos)
> +static void *_ima_measurements_start(struct seq_file *m, loff_t *pos,
> + struct list_head *head)
> {
> loff_t l = *pos;
> struct ima_queue_entry *qe;
>
> /* we need a lock since pos could point beyond last element */
> rcu_read_lock();
> - list_for_each_entry_rcu(qe, &ima_measurements, later) {
> + list_for_each_entry_rcu(qe, head, later) {
> if (!l--) {
> rcu_read_unlock();
> return qe;
> @@ -91,7 +104,18 @@ static void *ima_measurements_start(struct seq_file *m, loff_t *pos)
> return NULL;
> }
>
> -static void *ima_measurements_next(struct seq_file *m, void *v, loff_t *pos)
> +static void *ima_measurements_start(struct seq_file *m, loff_t *pos)
> +{
> + return _ima_measurements_start(m, pos, &ima_measurements);
> +}
> +
> +static void *ima_measurements_staged_start(struct seq_file *m, loff_t *pos)
> +{
> + return _ima_measurements_start(m, pos, &ima_measurements_staged);
> +}
> +
> +static void *_ima_measurements_next(struct seq_file *m, void *v, loff_t *pos,
> + struct list_head *head)
> {
> struct ima_queue_entry *qe = v;
>
> @@ -103,7 +127,18 @@ static void *ima_measurements_next(struct seq_file *m, void *v, loff_t *pos)
> rcu_read_unlock();
> (*pos)++;
>
> - return (&qe->later == &ima_measurements) ? NULL : qe;
> + return (&qe->later == head) ? NULL : qe;
> +}
> +
> +static void *ima_measurements_next(struct seq_file *m, void *v, loff_t *pos)
> +{
> + return _ima_measurements_next(m, v, pos, &ima_measurements);
> +}
> +
> +static void *ima_measurements_staged_next(struct seq_file *m, void *v,
> + loff_t *pos)
> +{
> + return _ima_measurements_next(m, v, pos, &ima_measurements_staged);
> }
>
> static void ima_measurements_stop(struct seq_file *m, void *v)
> @@ -202,16 +237,147 @@ static const struct seq_operations ima_measurments_seqops = {
> .show = ima_measurements_show
> };
>
> +static int _ima_measurements_open(struct inode *inode, struct file *file,
> + const struct seq_operations *seq_ops)
> +{
> + bool write = !!(file->f_mode & FMODE_WRITE);
> + int ret;
> +
> + if (write && !capable(CAP_SYS_ADMIN))
> + return -EPERM;
> +
> + mutex_lock(&ima_measure_lock);
> + if ((write && ima_measure_users != 0) ||
> + (!write && ima_measure_users < 0)) {
> + mutex_unlock(&ima_measure_lock);
> + return -EBUSY;
> + }
> +
> + ret = seq_open(file, seq_ops);
> + if (ret < 0) {
> + mutex_unlock(&ima_measure_lock);
> + return ret;
> + }
> +
> + if (write)
> + ima_measure_users--;
> + else
> + ima_measure_users++;
> +
> + mutex_unlock(&ima_measure_lock);
> + return ret;
> +}
> +
> static int ima_measurements_open(struct inode *inode, struct file *file)
> {
> - return seq_open(file, &ima_measurments_seqops);
> + return _ima_measurements_open(inode, file, &ima_measurments_seqops);
> +}
> +
> +static int ima_measurements_release(struct inode *inode, struct file *file)
> +{
> + bool write = !!(file->f_mode & FMODE_WRITE);
> + int ret;
> +
> + mutex_lock(&ima_measure_lock);
> + ret = seq_release(inode, file);
> + if (!ret) {
> + if (write)
> + ima_measure_users++;
> + else
> + ima_measure_users--;
> + }
> +
> + mutex_unlock(&ima_measure_lock);
> + return ret;
> }
>
> static const struct file_operations ima_measurements_ops = {
> .open = ima_measurements_open,
> .read = seq_read,
> .llseek = seq_lseek,
> - .release = seq_release,
> + .release = ima_measurements_release,
> +};
> +
> +static const struct seq_operations ima_measurments_staged_seqops = {
> + .start = ima_measurements_staged_start,
> + .next = ima_measurements_staged_next,
> + .stop = ima_measurements_stop,
> + .show = ima_measurements_show
> +};
> +
> +static int ima_measurements_staged_open(struct inode *inode, struct file *file)
> +{
> + return _ima_measurements_open(inode, file,
> + &ima_measurments_staged_seqops);
> +}
> +
> +static ssize_t ima_measurements_staged_read(struct file *file, char __user *buf,
> + size_t size, loff_t *ppos)
> +{
> + if (!ima_measurements_staged_exist)
> + return -ENOENT;
> +
> + return seq_read(file, buf, size, ppos);
> +}
> +
> +static ssize_t ima_measurements_staged_write(struct file *file,
> + const char __user *buf,
> + size_t datalen, loff_t *ppos)
> +{
> + char req[STAGED_REQ_LENGTH], *req_ptr = req;
> + unsigned long req_value;
> + bool trim = false;
> + int ret;
> +
> + if (*ppos > 0 || datalen < 2 || datalen > STAGED_REQ_LENGTH)
> + return -EINVAL;
> +
> + if (copy_from_user(req, buf, datalen) != 0)
> + return -EFAULT;
> +
> + if (req[datalen - 1] != '\n')
> + return -EINVAL;
> +
> + req[datalen - 1] = '\0';
> + req_ptr = req;
> +
> + switch (req[0]) {
> + case 'A':
> + if (datalen != 2 || req[1] != '\0')
> + return -EINVAL;
> +
> + ret = ima_queue_stage_trim(LONG_MAX, false);
> + break;
> + case 'D':
> + if (datalen != 2 || req[1] != '\0')
> + return -EINVAL;
> +
> + ret = ima_queue_delete_staged_trimmed(false);
> + break;
> + case '-':
> + trim = true;
> + req_ptr++;
> + fallthrough;
> + default:
> + ret = kstrtoul(req_ptr, 0, &req_value);
> + if (ret < 0)
> + return ret;
> +
> + ret = ima_queue_stage_trim(req_value, trim);
> + }
> +
> + if (ret < 0)
> + return ret;
> +
> + return datalen;
> +}
> +
> +static const struct file_operations ima_measurements_staged_ops = {
> + .open = ima_measurements_staged_open,
> + .read = ima_measurements_staged_read,
> + .write = ima_measurements_staged_write,
> + .llseek = seq_lseek,
> + .release = ima_measurements_release,
> };
>
> void ima_print_digest(struct seq_file *m, u8 *digest, u32 size)
> @@ -279,14 +445,37 @@ static const struct seq_operations ima_ascii_measurements_seqops = {
>
> static int ima_ascii_measurements_open(struct inode *inode, struct file *file)
> {
> - return seq_open(file, &ima_ascii_measurements_seqops);
> + return _ima_measurements_open(inode, file,
> + &ima_ascii_measurements_seqops);
> }
>
> static const struct file_operations ima_ascii_measurements_ops = {
> .open = ima_ascii_measurements_open,
> .read = seq_read,
> .llseek = seq_lseek,
> - .release = seq_release,
> + .release = ima_measurements_release,
> +};
> +
> +static const struct seq_operations ima_ascii_measurements_staged_seqops = {
> + .start = ima_measurements_staged_start,
> + .next = ima_measurements_staged_next,
> + .stop = ima_measurements_stop,
> + .show = ima_ascii_measurements_show
> +};
> +
> +static int ima_ascii_measurements_staged_open(struct inode *inode,
> + struct file *file)
> +{
> + return _ima_measurements_open(inode, file,
> + &ima_ascii_measurements_staged_seqops);
> +}
> +
> +static const struct file_operations ima_ascii_measurements_staged_ops = {
> + .open = ima_ascii_measurements_staged_open,
> + .read = ima_measurements_staged_read,
> + .write = ima_measurements_staged_write,
> + .llseek = seq_lseek,
> + .release = ima_measurements_release,
> };
>
> static ssize_t ima_read_policy(char *path)
> @@ -419,6 +608,25 @@ static int __init create_securityfs_measurement_lists(void)
> &ima_measurements_ops);
> if (IS_ERR(dentry))
> return PTR_ERR(dentry);
> +
> + sprintf(file_name, "ascii_runtime_measurements_staged_%s",
> + hash_algo_name[algo]);
> + dentry = securityfs_create_file(file_name,
> + S_IRUSR | S_IRGRP | S_IWUSR | S_IWGRP,
> + ima_dir, (void *)(uintptr_t)i,
> + &ima_ascii_measurements_staged_ops);
> + if (IS_ERR(dentry))
> + return PTR_ERR(dentry);
> +
> + sprintf(file_name, "binary_runtime_measurements_staged_%s",
> + hash_algo_name[algo]);
> + dentry = securityfs_create_file(file_name,
> + S_IRUSR | S_IRGRP |
> + S_IWUSR | S_IWGRP,
> + ima_dir, (void *)(uintptr_t)i,
> + &ima_measurements_staged_ops);
> + if (IS_ERR(dentry))
> + return PTR_ERR(dentry);
> }
>
> return 0;
> @@ -528,6 +736,20 @@ int __init ima_fs_init(void)
> goto out;
> }
>
> + dentry = securityfs_create_symlink("binary_runtime_measurements_staged",
> + ima_dir, "binary_runtime_measurements_staged_sha1", NULL);
> + if (IS_ERR(dentry)) {
> + ret = PTR_ERR(dentry);
> + goto out;
> + }
> +
> + dentry = securityfs_create_symlink("ascii_runtime_measurements_staged",
> + ima_dir, "ascii_runtime_measurements_staged_sha1", NULL);
> + if (IS_ERR(dentry)) {
> + ret = PTR_ERR(dentry);
> + goto out;
> + }
> +
> dentry = securityfs_create_file("runtime_measurements_count",
> S_IRUSR | S_IRGRP, ima_dir, NULL,
> &ima_measurements_count_ops);
> diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c
> index 7362f68f2d8b..13c7e78aeefd 100644
> --- a/security/integrity/ima/ima_kexec.c
> +++ b/security/integrity/ima/ima_kexec.c
> @@ -40,8 +40,8 @@ void ima_measure_kexec_event(const char *event_name)
> long len;
> int n;
>
> - buf_size = ima_get_binary_runtime_size();
> - len = atomic_long_read(&ima_htable.len);
> + buf_size = ima_get_binary_runtime_size(BINARY_SIZE_FULL);
> + len = atomic_long_read(&ima_htable.len[BINARY_SIZE_FULL]);
>
> n = scnprintf(ima_kexec_event, IMA_KEXEC_EVENT_LEN,
> "kexec_segment_size=%lu;ima_binary_runtime_size=%lu;"
> @@ -78,6 +78,17 @@ static int ima_alloc_kexec_file_buf(size_t segment_size)
> return 0;
> }
>
> +static int ima_dump_measurement(struct ima_kexec_hdr *khdr,
> + struct ima_queue_entry *qe)
> +{
> + if (ima_kexec_file.count >= ima_kexec_file.size)
> + return -EINVAL;
> +
> + khdr->count++;
> + ima_measurements_show(&ima_kexec_file, qe);
> + return 0;
> +}
> +
> static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer,
> unsigned long segment_size)
> {
> @@ -93,17 +104,25 @@ static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer,
>
> memset(&khdr, 0, sizeof(khdr));
> khdr.version = 1;
> - /* This is an append-only list, no need to hold the RCU read lock */
> - list_for_each_entry_rcu(qe, &ima_measurements, later, true) {
> - if (ima_kexec_file.count < ima_kexec_file.size) {
> - khdr.count++;
> - ima_measurements_show(&ima_kexec_file, qe);
> - } else {
> - ret = -EINVAL;
> +
> + /* It can race with ima_queue_stage_trim(). */
> + mutex_lock(&ima_extend_list_mutex);
> +
> + list_for_each_entry(qe, &ima_measurements_staged, later) {
> + ret = ima_dump_measurement(&khdr, qe);
> + if (ret < 0)
> + break;
> + }
> +
> + list_for_each_entry(qe, &ima_measurements, later) {
> + if (!ret)
> + ret = ima_dump_measurement(&khdr, qe);
> + if (ret < 0)
> break;
> - }
> }
>
> + mutex_unlock(&ima_extend_list_mutex);
> +
> /*
> * fill in reserved space with some buffer details
> * (eg. version, buffer size, number of measurements)
> @@ -157,7 +176,8 @@ void ima_add_kexec_buffer(struct kimage *image)
> else
> extra_memory = CONFIG_IMA_KEXEC_EXTRA_MEMORY_KB * 1024;
>
> - binary_runtime_size = ima_get_binary_runtime_size() + extra_memory;
> + binary_runtime_size = ima_get_binary_runtime_size(BINARY_SIZE_STAGED) +
> + extra_memory;
>
> if (binary_runtime_size >= ULONG_MAX - PAGE_SIZE)
> kexec_segment_size = ULONG_MAX;
> diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c
> index 590637e81ad1..7dfa24b8ae31 100644
> --- a/security/integrity/ima/ima_queue.c
> +++ b/security/integrity/ima/ima_queue.c
> @@ -22,19 +22,32 @@
>
> #define AUDIT_CAUSE_LEN_MAX 32
>
> +bool ima_flush_htable;
> +static int __init ima_flush_htable_setup(char *str)
> +{
> + ima_flush_htable = true;
> + return 1;
> +}
> +__setup("ima_flush_htable", ima_flush_htable_setup);
> +
> /* pre-allocated array of tpm_digest structures to extend a PCR */
> static struct tpm_digest *digests;
>
> LIST_HEAD(ima_measurements); /* list of all measurements */
> +LIST_HEAD(ima_measurements_staged); /* list of staged measurements */
> +static LIST_HEAD(ima_measurements_trim); /* list of measurements to trim */
> +bool ima_measurements_staged_exist; /* If there are staged measurements */
> #ifdef CONFIG_IMA_KEXEC
> -static unsigned long binary_runtime_size;
> +static unsigned long binary_runtime_size[BINARY__LAST];
> #else
> -static unsigned long binary_runtime_size = ULONG_MAX;
> +static unsigned long binary_runtime_size[BINARY_SIZE] = ULONG_MAX;
> +static unsigned long binary_runtime_size[BINARY_SIZE_FULL] = ULONG_MAX;
> +static unsigned long binary_runtime_size[BINARY_SIZE_STAGED] = ULONG_MAX;
> #endif
>
> /* key: inode (before secure-hashing a file) */
> struct ima_h_table ima_htable = {
> - .len = ATOMIC_LONG_INIT(0),
> + .len = { ATOMIC_LONG_INIT(0) },
> .violations = ATOMIC_LONG_INIT(0),
> .queue[0 ... IMA_MEASURE_HTABLE_SIZE - 1] = HLIST_HEAD_INIT
> };
> @@ -43,7 +56,7 @@ struct ima_h_table ima_htable = {
> * and extending the TPM PCR aggregate. Since tpm_extend can take
> * long (and the tpm driver uses a mutex), we can't use the spinlock.
> */
> -static DEFINE_MUTEX(ima_extend_list_mutex);
> +DEFINE_MUTEX(ima_extend_list_mutex);
>
> /*
> * Used internally by the kernel to suspend measurements.
> @@ -101,7 +114,7 @@ static int ima_add_digest_entry(struct ima_template_entry *entry,
> bool update_htable)
> {
> struct ima_queue_entry *qe;
> - unsigned int key;
> + unsigned int i, key;
>
> qe = kmalloc(sizeof(*qe), GFP_KERNEL);
> if (qe == NULL) {
> @@ -113,18 +126,23 @@ static int ima_add_digest_entry(struct ima_template_entry *entry,
> INIT_LIST_HEAD(&qe->later);
> list_add_tail_rcu(&qe->later, &ima_measurements);
>
> - atomic_long_inc(&ima_htable.len);
> + for (i = 0; i < BINARY__LAST; i++)
> + atomic_long_inc(&ima_htable.len[i]);
> +
> if (update_htable) {
> key = ima_hash_key(entry->digests[ima_hash_algo_idx].digest);
> hlist_add_head_rcu(&qe->hnext, &ima_htable.queue[key]);
> }
>
> - if (binary_runtime_size != ULONG_MAX) {
> + if (binary_runtime_size[BINARY_SIZE_FULL] != ULONG_MAX) {
> int size;
>
> size = get_binary_runtime_size(entry);
> - binary_runtime_size = (binary_runtime_size < ULONG_MAX - size) ?
> - binary_runtime_size + size : ULONG_MAX;
> +
> + for (i = 0; i < BINARY__LAST; i++)
> + binary_runtime_size[i] =
> + (binary_runtime_size[i] < ULONG_MAX - size) ?
> + binary_runtime_size[i] + size : ULONG_MAX;
> }
> return 0;
> }
> @@ -134,12 +152,18 @@ static int ima_add_digest_entry(struct ima_template_entry *entry,
> * entire binary_runtime_measurement list, including the ima_kexec_hdr
> * structure.
> */
> -unsigned long ima_get_binary_runtime_size(void)
> +unsigned long ima_get_binary_runtime_size(enum binary_size_types type)
> {
> - if (binary_runtime_size >= (ULONG_MAX - sizeof(struct ima_kexec_hdr)))
> + unsigned long val;
> +
> + mutex_lock(&ima_extend_list_mutex);
> + val = binary_runtime_size[type];
> + mutex_unlock(&ima_extend_list_mutex);
> +
> + if (val >= (ULONG_MAX - sizeof(struct ima_kexec_hdr)))
> return ULONG_MAX;
> else
> - return binary_runtime_size + sizeof(struct ima_kexec_hdr);
> + return val + sizeof(struct ima_kexec_hdr);
> }
>
> static int ima_pcr_extend(struct tpm_digest *digests_arg, int pcr)
> @@ -220,6 +244,127 @@ int ima_add_template_entry(struct ima_template_entry *entry, int violation,
> return result;
> }
>
> +int ima_queue_stage_trim(unsigned long req_value, bool trim)
> +{
> + unsigned long req_value_copy = req_value, to_remove = 0;
> + struct list_head *moved = &ima_measurements_staged;
> + struct ima_queue_entry *qe;
> +
> + if (req_value == 0 || req_value > LONG_MAX)
> + return -EINVAL;
> +
> + if (ima_measurements_staged_exist)
> + return -EEXIST;
> +
> + if (trim)
> + moved = &ima_measurements_trim;
> +
> + mutex_lock(&ima_extend_list_mutex);
> + if (list_empty(&ima_measurements)) {
> + mutex_unlock(&ima_extend_list_mutex);
> + return -ENOENT;
> + }
> +
> + if (req_value == LONG_MAX) {
> + list_replace(&ima_measurements, moved);
> + INIT_LIST_HEAD(&ima_measurements);
> + atomic_long_set(&ima_htable.len[BINARY_SIZE], 0);
> + if (IS_ENABLED(CONFIG_IMA_KEXEC))
> + binary_runtime_size[BINARY_SIZE] = 0;
> +
> + if (trim) {
> + atomic_long_set(&ima_htable.len[BINARY_SIZE_STAGED], 0);
> + if (IS_ENABLED(CONFIG_IMA_KEXEC))
> + binary_runtime_size[BINARY_SIZE_STAGED] = 0;
> + }
> + } else {
> + list_for_each_entry(qe, &ima_measurements, later) {
> + to_remove += get_binary_runtime_size(qe->entry);
> + if (--req_value_copy == 0)
> + break;
> + }
> +
> + if (req_value_copy > 0) {
> + mutex_unlock(&ima_extend_list_mutex);
> + return -ENOENT;
> + }
> +
> + __list_cut_position(moved, &ima_measurements, &qe->later);
> + atomic_long_sub(req_value, &ima_htable.len[BINARY_SIZE]);
> + if (IS_ENABLED(CONFIG_IMA_KEXEC))
> + binary_runtime_size[BINARY_SIZE] -= to_remove;
> +
> + if (trim) {
> + atomic_long_sub(req_value,
> + &ima_htable.len[BINARY_SIZE_STAGED]);
> + if (IS_ENABLED(CONFIG_IMA_KEXEC))
> + binary_runtime_size[BINARY_SIZE_STAGED] -=
> + to_remove;
> + }
> + }
> +
> + if (ima_flush_htable)
> + /* Either staged/trimmed entries are removed from hash table. */
> + list_for_each_entry(qe, moved, later)
> + /* It can race with ima_lookup_digest_entry(). */
> + hlist_del_rcu(&qe->hnext);
> +
> + mutex_unlock(&ima_extend_list_mutex);
> + ima_measurements_staged_exist = true;
> +
> + if (ima_flush_htable)
> + synchronize_rcu();
> +
> + if (trim)
> + return ima_queue_delete_staged_trimmed(true);
> +
> + return 0;
> +}
> +
> +int ima_queue_delete_staged_trimmed(bool staged_moved)
> +{
> + struct ima_queue_entry *qe, *qe_tmp;
> + unsigned int i;
> +
> + if (!ima_measurements_staged_exist)
> + return -ENOENT;
> +
> + if (!staged_moved) {
> + mutex_lock(&ima_extend_list_mutex);
> + list_replace(&ima_measurements_staged, &ima_measurements_trim);
> + INIT_LIST_HEAD(&ima_measurements_staged);
> + atomic_long_set(&ima_htable.len[BINARY_SIZE_STAGED], 0);
> + if (IS_ENABLED(CONFIG_IMA_KEXEC))
> + binary_runtime_size[BINARY_SIZE_STAGED] = 0;
> +
> + mutex_unlock(&ima_extend_list_mutex);
> + }
> +
> + list_for_each_entry_safe(qe, qe_tmp, &ima_measurements_trim, later) {
> + /*
> + * Ok because after list delete qe is only accessed by
> + * ima_lookup_digest_entry().
> + */
> + for (i = 0; i < qe->entry->template_desc->num_fields; i++) {
> + kfree(qe->entry->template_data[i].data);
> + qe->entry->template_data[i].data = NULL;
> + qe->entry->template_data[i].len = 0;
> + }
> +
> + list_del(&qe->later);
> +
> + /* No leak if !ima_flush_htable, referenced by ima_htable. */
> + if (ima_flush_htable) {
> + kfree(qe->entry->digests);
> + kfree(qe->entry);
> + kfree(qe);
> + }
> + }
> +
> + ima_measurements_staged_exist = false;
> + return 0;
> +}
> +
> int ima_restore_measurement_entry(struct ima_template_entry *entry)
> {
> int result = 0;
^ permalink raw reply
* Re: [PATCH v2 07/13] mm: update secretmem to use VMA flags on mmap_prepare
From: Lorenzo Stoakes @ 2026-01-28 16:44 UTC (permalink / raw)
To: Andrew Morton
Cc: Jarkko Sakkinen, Dave Hansen, Thomas Gleixner, Ingo Molnar,
Borislav Petkov, x86, H . Peter Anvin, Arnd Bergmann,
Greg Kroah-Hartman, Dan Williams, Vishal Verma, Dave Jiang,
Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, David Airlie,
Simona Vetter, Jani Nikula, Joonas Lahtinen, Rodrigo Vivi,
Tvrtko Ursulin, Christian Koenig, Huang Rui, Matthew Auld,
Matthew Brost, Alexander Viro, Christian Brauner, Jan Kara,
Benjamin LaHaise, Gao Xiang, Chao Yu, Yue Hu, Jeffle Xu,
Sandeep Dhavale, Hongbo Li, Chunhai Guo, Theodore Ts'o,
Andreas Dilger, Muchun Song, Oscar Salvador, David Hildenbrand,
Konstantin Komarov, Mike Marshall, Martin Brandenburg, Tony Luck,
Reinette Chatre, Dave Martin, James Morse, Babu Moger,
Carlos Maiolino, Damien Le Moal, Naohiro Aota, Johannes Thumshirn,
Matthew Wilcox, Liam R . Howlett, Vlastimil Babka, Mike Rapoport,
Suren Baghdasaryan, Michal Hocko, Hugh Dickins, Baolin Wang,
Zi Yan, Nico Pache, Ryan Roberts, Dev Jain, Barry Song,
Lance Yang, Jann Horn, Pedro Falcato, David Howells, Paul Moore,
James Morris, Serge E . Hallyn, Yury Norov, Rasmus Villemoes,
linux-sgx, linux-kernel, nvdimm, linux-cxl, dri-devel, intel-gfx,
linux-fsdevel, linux-aio, linux-erofs, linux-ext4, linux-mm,
ntfs3, devel, linux-xfs, keyrings, linux-security-module,
Jason Gunthorpe
In-Reply-To: <a243a09b0a5d0581e963d696de1735f61f5b2075.1769097829.git.lorenzo.stoakes@oracle.com>
Hi Andrew,
Could you apply the below fix-patch to resolve the issue Chris's AI checks
detected, I missed out one caller of mlock_future_ok() (a very human mistake
;)).
Cheers, Lorenzo
----8<----
From 652146b4d93a31bb6f9da9428ddaab8a4a53e170 Mon Sep 17 00:00:00 2001
From: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Date: Wed, 28 Jan 2026 16:41:55 +0000
Subject: [PATCH] fix
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
---
mm/mmap.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index 354479c95896..5dfe57b6d69a 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -108,7 +108,8 @@ static int check_brk_limits(unsigned long addr, unsigned long len)
if (IS_ERR_VALUE(mapped_addr))
return mapped_addr;
- return mlock_future_ok(current->mm, current->mm->def_flags, len)
+ return mlock_future_ok(current->mm,
+ current->mm->def_flags & VM_LOCKED, len)
? 0 : -EAGAIN;
}
--
2.52.0
^ permalink raw reply related
* Re: [PATCH v2 07/13] mm: update secretmem to use VMA flags on mmap_prepare
From: Lorenzo Stoakes @ 2026-01-28 16:04 UTC (permalink / raw)
To: Chris Mason
Cc: Andrew Morton, Jarkko Sakkinen, Dave Hansen, Thomas Gleixner,
Ingo Molnar, Borislav Petkov, x86, H . Peter Anvin, Arnd Bergmann,
Greg Kroah-Hartman, Dan Williams, Vishal Verma, Dave Jiang,
Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, David Airlie,
Simona Vetter, Jani Nikula, Joonas Lahtinen, Rodrigo Vivi,
Tvrtko Ursulin, Christian Koenig, Huang Rui, Matthew Auld,
Matthew Brost, Alexander Viro, Christian Brauner, Jan Kara,
Benjamin LaHaise, Gao Xiang, Chao Yu, Yue Hu, Jeffle Xu,
Sandeep Dhavale, Hongbo Li, Chunhai Guo, Theodore Ts'o,
Andreas Dilger, Muchun Song, Oscar Salvador, David Hildenbrand,
Konstantin Komarov, Mike Marshall, Martin Brandenburg, Tony Luck,
Reinette Chatre, Dave Martin, James Morse, Babu Moger,
Carlos Maiolino, Damien Le Moal, Naohiro Aota, Johannes Thumshirn,
Matthew Wilcox, Liam R . Howlett, Vlastimil Babka, Mike Rapoport,
Suren Baghdasaryan, Michal Hocko, Hugh Dickins, Baolin Wang,
Zi Yan, Nico Pache, Ryan Roberts, Dev Jain, Barry Song,
Lance Yang, Jann Horn, Pedro Falcato, David Howells, Paul Moore,
James Morris, Serge E . Hallyn, Yury Norov, Rasmus Villemoes,
linux-sgx, linux-kernel, nvdimm, linux-cxl, dri-devel, intel-gfx,
linux-fsdevel, linux-aio, linux-erofs, linux-ext4, linux-mm,
ntfs3, devel, linux-xfs, keyrings, linux-security-module,
Jason Gunthorpe
In-Reply-To: <20260128121200.283932-1-clm@meta.com>
On Wed, Jan 28, 2026 at 04:08:36AM -0800, Chris Mason wrote:
> Lorenzo Stoakes <lorenzo.stoakes@oracle.com> wrote:
> > This patch updates secretmem to use the new vma_flags_t type which will
> > soon supersede vm_flags_t altogether.
> >
> > In order to make this change we also have to update mlock_future_ok(), we
> > replace the vm_flags_t parameter with a simple boolean is_vma_locked one,
> > which also simplifies the invocation here.
> >
> > This is laying the groundwork for eliminating the vm_flags_t in
> > vm_area_desc and more broadly throughout the kernel.
> >
>
> Hi everyone,
>
> Running mm-new through AI review flagged this one:
>
> > diff --git a/mm/mmap.c b/mm/mmap.c
> > --- a/mm/mmap.c
> > +++ b/mm/mmap.c
> > @@ -225,12 +225,12 @@ static inline unsigned long round_hint_to_min(unsigned long hint)
> > return hint;
> > }
> >
> > -bool mlock_future_ok(const struct mm_struct *mm, vm_flags_t vm_flags,
> > - unsigned long bytes)
> > +bool mlock_future_ok(const struct mm_struct *mm, bool is_vma_locked,
> > + unsigned long bytes)
> > {
> > unsigned long locked_pages, limit_pages;
> >
> > - if (!(vm_flags & VM_LOCKED) || capable(CAP_IPC_LOCK))
> > + if (!is_vma_locked || capable(CAP_IPC_LOCK))
> > return true;
>
> [ ... ]
>
> > @@ -416,7 +416,7 @@
> > if (!can_do_mlock())
> > return -EPERM;
> >
> > - if (!mlock_future_ok(mm, vm_flags, len))
> > + if (!mlock_future_ok(mm, vm_flags & VM_LOCKED, len))
> > return -EAGAIN;
>
> This looks correct - do_mmap() now extracts the VM_LOCKED bit from
> vm_flags and passes that to mlock_future_ok().
>
> However, it appears check_brk_limits() was not updated when
> mlock_future_ok() changed its signature. The function at mm/mmap.c:111
> still passes the raw def_flags value:
>
> return mlock_future_ok(current->mm, current->mm->def_flags, len)
> ? 0 : -EAGAIN;
Ack, the C 'type system' strikes again :) will send a fix-patch.
>
> When def_flags has any bit set, this converts to true, incorrectly
> triggering mlock limit checks even when VM_LOCKED is not set. Should
> this be passing (current->mm->def_flags & VM_LOCKED) instead?
>
> [ ... ]
>
> Additionally, the test stub at tools/testing/vma/vma_internal.h:1627
> still has the old signature (mm, vm_flags_t vm_flags, bytes) while the
> production code now uses (mm, bool is_vma_locked, bytes). This could
> cause compilation issues or mask bugs in the test suite.
Ack, I can fix that later. The VMA test headers have been split and it's too
much merge pain to address at this point given the tests aren't impacted by this
yet. Is on todo!
>
>
Cheers, Lorenzo
^ permalink raw reply
* Re: [PATCH v2 00/13] mm: add bitmap VMA flag helpers and convert all mmap_prepare to use them
From: Pedro Falcato @ 2026-01-28 15:50 UTC (permalink / raw)
To: Lorenzo Stoakes
Cc: Yury Norov, Andrew Morton, Jarkko Sakkinen, Dave Hansen,
Thomas Gleixner, Ingo Molnar, Borislav Petkov, x86,
H . Peter Anvin, Arnd Bergmann, Greg Kroah-Hartman, Dan Williams,
Vishal Verma, Dave Jiang, Maarten Lankhorst, Maxime Ripard,
Thomas Zimmermann, David Airlie, Simona Vetter, Jani Nikula,
Joonas Lahtinen, Rodrigo Vivi, Tvrtko Ursulin, Christian Koenig,
Huang Rui, Matthew Auld, Matthew Brost, Alexander Viro,
Christian Brauner, Jan Kara, Benjamin LaHaise, Gao Xiang, Chao Yu,
Yue Hu, Jeffle Xu, Sandeep Dhavale, Hongbo Li, Chunhai Guo,
Theodore Ts'o, Andreas Dilger, Muchun Song, Oscar Salvador,
David Hildenbrand, Konstantin Komarov, Mike Marshall,
Martin Brandenburg, Tony Luck, Reinette Chatre, Dave Martin,
James Morse, Babu Moger, Carlos Maiolino, Damien Le Moal,
Naohiro Aota, Johannes Thumshirn, Matthew Wilcox,
Liam R . Howlett, Vlastimil Babka, Mike Rapoport,
Suren Baghdasaryan, Michal Hocko, Hugh Dickins, Baolin Wang,
Zi Yan, Nico Pache, Ryan Roberts, Dev Jain, Barry Song,
Lance Yang, Jann Horn, David Howells, Paul Moore, James Morris,
Serge E . Hallyn, Yury Norov, Rasmus Villemoes, linux-sgx,
linux-kernel, nvdimm, linux-cxl, dri-devel, intel-gfx,
linux-fsdevel, linux-aio, linux-erofs, linux-ext4, linux-mm,
ntfs3, devel, linux-xfs, keyrings, linux-security-module,
Jason Gunthorpe
In-Reply-To: <c7452c5f-e42f-4595-8680-bd1d5726be38@lucifer.local>
On Wed, Jan 28, 2026 at 09:33:44AM +0000, Lorenzo Stoakes wrote:
> On Tue, Jan 27, 2026 at 04:36:44PM -0500, Yury Norov wrote:
> > On Tue, Jan 27, 2026 at 02:40:03PM +0000, Lorenzo Stoakes wrote:
> > > On Tue, Jan 27, 2026 at 08:53:44AM -0500, Yury Norov wrote:
> > > > On Thu, Jan 22, 2026 at 04:06:09PM +0000, Lorenzo Stoakes wrote:
> >
> > ...
> >
> > > > Even if you expect adding more flags, u128 would double your capacity,
> > > > and people will still be able to use language-supported operation on
> > > > the bits in flag. Which looks simpler to me...
> > >
> > > u128 isn't supported on all architectures, VMA flags have to have absolutely
> >
> > What about big integers?
> >
> > typedef unsigned _BitInt(VMA_FLAGS_COUNT) vma_flags_t
>
> There is no use of _BitInt anywhere in the kernel. That seems to be a
> C23-only feature with limited compiler support that we simply couldn't use
> yet.
>
> https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2025/p3639r0.html tells
> me that it's supported in clang 16+ and gcc 14+.
>
> We cannot put such a restriction on compilers in the kernel, obviously.
>
> >
> > > We want to be able to arbitrarily extend this as we please in the future. So
> > > using u64 wouldn't buy us _anything_ except getting the 32-bit kernels in line.
> >
> > So enabling 32-bit arches is a big deal, even if it's a temporary
> > solution. Again, how many flags in your opinion are blocked because of
> > 32-bit integer limitation? How soon 64-bit capacity will get fully
> > used?
>
> In my opinion? I'm not sure where my opinion comes into this? There are 43 VMA
> flags and 32-bits available in 32-bit kernels.
>
> As I said to you before Yury, when adding new flags you have to add a whole
> load of mess of #ifdef CONFIG_64BIT ... #endif etc. around things that have
> nothing to do with 64-bit vs 32-bit architecture as a result.
>
> It's a mess, we've run out.
>
> Also something that might not have occurred to you - there is a chilling
> effect of limited VMA flag availability - the bar to adding flags is
> higher, and features that might have used VMA flags but need general kernel
> support (incl. 32-bit) have to find other ways to store state like this.
>
For the record, I fully agree with all of the points you made. I don't think
it makes sense to hold this change back waiting for a feature that right
now is relatively unobtainable (also IIRC the ABI around _BitInt was a bit
unstable and confusing in general, I don't know if that changed).
The goals are to:
1) get more than sizeof(unsigned long) * 8 flags so we don't have to uglify
and gatekeep things behind 64-bit. Also letting us use VMA flags more freely.
2) not cause any performance/codegen regression
Yes, the current patchset (and the current state of things too) uglifies
things a bit, but it also provides things like type safety which are sorely
needed here. And which 128-bit integers, or N-bit integers would not provide.
And if any of the above suddenly become available to us in the future, it
will be trivial to change because the VMA flags types will be fully
encapsulated with proper accessors.
Or perhaps we'll rewrite it all in rust by the end of the decade and this is
all a moot point, who knows ;)
--
Pedro
^ permalink raw reply
* Re: [PATCH v2 07/13] mm: update secretmem to use VMA flags on mmap_prepare
From: Chris Mason @ 2026-01-28 12:08 UTC (permalink / raw)
To: Lorenzo Stoakes
Cc: Andrew Morton, Jarkko Sakkinen, Dave Hansen, Thomas Gleixner,
Ingo Molnar, Borislav Petkov, x86, H . Peter Anvin, Arnd Bergmann,
Greg Kroah-Hartman, Dan Williams, Vishal Verma, Dave Jiang,
Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, David Airlie,
Simona Vetter, Jani Nikula, Joonas Lahtinen, Rodrigo Vivi,
Tvrtko Ursulin, Christian Koenig, Huang Rui, Matthew Auld,
Matthew Brost, Alexander Viro, Christian Brauner, Jan Kara,
Benjamin LaHaise, Gao Xiang, Chao Yu, Yue Hu, Jeffle Xu,
Sandeep Dhavale, Hongbo Li, Chunhai Guo, Theodore Ts'o,
Andreas Dilger, Muchun Song, Oscar Salvador, David Hildenbrand,
Konstantin Komarov, Mike Marshall, Martin Brandenburg, Tony Luck,
Reinette Chatre, Dave Martin, James Morse, Babu Moger,
Carlos Maiolino, Damien Le Moal, Naohiro Aota, Johannes Thumshirn,
Matthew Wilcox, Liam R . Howlett, Vlastimil Babka, Mike Rapoport,
Suren Baghdasaryan, Michal Hocko, Hugh Dickins, Baolin Wang,
Zi Yan, Nico Pache, Ryan Roberts, Dev Jain, Barry Song,
Lance Yang, Jann Horn, Pedro Falcato, David Howells, Paul Moore,
James Morris, Serge E . Hallyn, Yury Norov, Rasmus Villemoes,
linux-sgx, linux-kernel, nvdimm, linux-cxl, dri-devel, intel-gfx,
linux-fsdevel, linux-aio, linux-erofs, linux-ext4, linux-mm,
ntfs3, devel, linux-xfs, keyrings, linux-security-module,
Jason Gunthorpe
In-Reply-To: <a243a09b0a5d0581e963d696de1735f61f5b2075.1769097829.git.lorenzo.stoakes@oracle.com>
Lorenzo Stoakes <lorenzo.stoakes@oracle.com> wrote:
> This patch updates secretmem to use the new vma_flags_t type which will
> soon supersede vm_flags_t altogether.
>
> In order to make this change we also have to update mlock_future_ok(), we
> replace the vm_flags_t parameter with a simple boolean is_vma_locked one,
> which also simplifies the invocation here.
>
> This is laying the groundwork for eliminating the vm_flags_t in
> vm_area_desc and more broadly throughout the kernel.
>
Hi everyone,
Running mm-new through AI review flagged this one:
> diff --git a/mm/mmap.c b/mm/mmap.c
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -225,12 +225,12 @@ static inline unsigned long round_hint_to_min(unsigned long hint)
> return hint;
> }
>
> -bool mlock_future_ok(const struct mm_struct *mm, vm_flags_t vm_flags,
> - unsigned long bytes)
> +bool mlock_future_ok(const struct mm_struct *mm, bool is_vma_locked,
> + unsigned long bytes)
> {
> unsigned long locked_pages, limit_pages;
>
> - if (!(vm_flags & VM_LOCKED) || capable(CAP_IPC_LOCK))
> + if (!is_vma_locked || capable(CAP_IPC_LOCK))
> return true;
[ ... ]
> @@ -416,7 +416,7 @@
> if (!can_do_mlock())
> return -EPERM;
>
> - if (!mlock_future_ok(mm, vm_flags, len))
> + if (!mlock_future_ok(mm, vm_flags & VM_LOCKED, len))
> return -EAGAIN;
This looks correct - do_mmap() now extracts the VM_LOCKED bit from
vm_flags and passes that to mlock_future_ok().
However, it appears check_brk_limits() was not updated when
mlock_future_ok() changed its signature. The function at mm/mmap.c:111
still passes the raw def_flags value:
return mlock_future_ok(current->mm, current->mm->def_flags, len)
? 0 : -EAGAIN;
When def_flags has any bit set, this converts to true, incorrectly
triggering mlock limit checks even when VM_LOCKED is not set. Should
this be passing (current->mm->def_flags & VM_LOCKED) instead?
[ ... ]
Additionally, the test stub at tools/testing/vma/vma_internal.h:1627
still has the old signature (mm, vm_flags_t vm_flags, bytes) while the
production code now uses (mm, bool is_vma_locked, bytes). This could
cause compilation issues or mask bugs in the test suite.
^ permalink raw reply
* Re: [PATCH] xfrm: kill xfrm_dev_{state,policy}_flush_secctx_check()
From: Tetsuo Handa @ 2026-01-28 10:28 UTC (permalink / raw)
To: Paul Moore, SELinux, linux-security-module
Cc: Steffen Klassert, Herbert Xu, David S. Miller, Eric Dumazet,
Jakub Kicinski, Paolo Abeni, Simon Horman, Network Development
In-Reply-To: <CAHC9VhQq6jY63kYEQCp2t89Vv+_PDqv54RV6TO_TePDQyU6Vug@mail.gmail.com>
On 2026/01/28 6:59, Paul Moore wrote:
> It sounds like we either need to confirm that
> security_xfrm_{policy,state}_delete() is already present in all code
> paths that result in SPD/SAD deletions (in a place that can safely
> fail and return an error),
Yes.
> or we need to place
> xfrm_dev_{policy,state}_flush_secctx_check() in a location that can
> safely fail.
Did you mean xfrm_{policy,state}_flush_secctx_check() ?
Regarding xfrm_policy_flush() as an example, we can observe that we are
calling LSM hooks for must-not-fail callers. If the task_valid argument was
meant to be interpreted as whether to call LSM hooks, xfrm_policy_flush() needs
below change.
int xfrm_policy_flush(struct net *net, u8 type, bool task_valid)
{
(...snipped...)
- err = xfrm_policy_flush_secctx_check(net, type, task_valid);
+ err = task_valid ? xfrm_policy_flush_secctx_check(net, type, task_valid) : 0;
(...snipped...)
}
> The patch doesn't relocate
> xfrm_dev_{policy,state}_flush_secctx_check() and I don't really see
> any mention about security_xfrm_{policy,state}_delete() in the patch
> or description;
> have you verified that the LSM xfrm hooks are still
> being called to authorize the removals?
Please distinguish caller for "delete" and caller for "release".
LSM xfrm hooks need to be called for "delete" callers, but
LSM xfrm hooks need to be bypassed for "release" callers.
Maybe task_valid == true is for "delete" callers and task_valid == false is
for "release" callers; though it seems that some locations are passing wrong
task_valid flag (e.g. xfrm_dev_down() is passing task_valid == true despite
it is a "release" caller).
If 'task_valid == true is for "delete" callers and task_valid == false is for
"release" callers' does not hold, we might need to add a "forced" flag
(which is interpreted as whether LSM hooks must be bypassed) like
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit?h=next-20260123&id=fc0f090e41e652d158f946c616cdd82baed3c8f4
does.
Anyway, this patch which kills xfrm_dev_{state,policy}_flush_secctx_check()
can be applied as-is because all callers are "release" callers.
^ permalink raw reply
* Re: [PATCH v2 00/13] mm: add bitmap VMA flag helpers and convert all mmap_prepare to use them
From: Lorenzo Stoakes @ 2026-01-28 9:33 UTC (permalink / raw)
To: Yury Norov
Cc: Andrew Morton, Jarkko Sakkinen, Dave Hansen, Thomas Gleixner,
Ingo Molnar, Borislav Petkov, x86, H . Peter Anvin, Arnd Bergmann,
Greg Kroah-Hartman, Dan Williams, Vishal Verma, Dave Jiang,
Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, David Airlie,
Simona Vetter, Jani Nikula, Joonas Lahtinen, Rodrigo Vivi,
Tvrtko Ursulin, Christian Koenig, Huang Rui, Matthew Auld,
Matthew Brost, Alexander Viro, Christian Brauner, Jan Kara,
Benjamin LaHaise, Gao Xiang, Chao Yu, Yue Hu, Jeffle Xu,
Sandeep Dhavale, Hongbo Li, Chunhai Guo, Theodore Ts'o,
Andreas Dilger, Muchun Song, Oscar Salvador, David Hildenbrand,
Konstantin Komarov, Mike Marshall, Martin Brandenburg, Tony Luck,
Reinette Chatre, Dave Martin, James Morse, Babu Moger,
Carlos Maiolino, Damien Le Moal, Naohiro Aota, Johannes Thumshirn,
Matthew Wilcox, Liam R . Howlett, Vlastimil Babka, Mike Rapoport,
Suren Baghdasaryan, Michal Hocko, Hugh Dickins, Baolin Wang,
Zi Yan, Nico Pache, Ryan Roberts, Dev Jain, Barry Song,
Lance Yang, Jann Horn, Pedro Falcato, David Howells, Paul Moore,
James Morris, Serge E . Hallyn, Yury Norov, Rasmus Villemoes,
linux-sgx, linux-kernel, nvdimm, linux-cxl, dri-devel, intel-gfx,
linux-fsdevel, linux-aio, linux-erofs, linux-ext4, linux-mm,
ntfs3, devel, linux-xfs, keyrings, linux-security-module,
Jason Gunthorpe
In-Reply-To: <aXkv7DSUbdY-RD5d@yury>
On Tue, Jan 27, 2026 at 04:36:44PM -0500, Yury Norov wrote:
> On Tue, Jan 27, 2026 at 02:40:03PM +0000, Lorenzo Stoakes wrote:
> > On Tue, Jan 27, 2026 at 08:53:44AM -0500, Yury Norov wrote:
> > > On Thu, Jan 22, 2026 at 04:06:09PM +0000, Lorenzo Stoakes wrote:
>
> ...
>
> > > Even if you expect adding more flags, u128 would double your capacity,
> > > and people will still be able to use language-supported operation on
> > > the bits in flag. Which looks simpler to me...
> >
> > u128 isn't supported on all architectures, VMA flags have to have absolutely
>
> What about big integers?
>
> typedef unsigned _BitInt(VMA_FLAGS_COUNT) vma_flags_t
There is no use of _BitInt anywhere in the kernel. That seems to be a
C23-only feature with limited compiler support that we simply couldn't use
yet.
https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2025/p3639r0.html tells
me that it's supported in clang 16+ and gcc 14+.
We cannot put such a restriction on compilers in the kernel, obviously.
>
> > We want to be able to arbitrarily extend this as we please in the future. So
> > using u64 wouldn't buy us _anything_ except getting the 32-bit kernels in line.
>
> So enabling 32-bit arches is a big deal, even if it's a temporary
> solution. Again, how many flags in your opinion are blocked because of
> 32-bit integer limitation? How soon 64-bit capacity will get fully
> used?
In my opinion? I'm not sure where my opinion comes into this? There are 43 VMA
flags and 32-bits available in 32-bit kernels.
As I said to you before Yury, when adding new flags you have to add a whole
load of mess of #ifdef CONFIG_64BIT ... #endif etc. around things that have
nothing to do with 64-bit vs 32-bit architecture as a result.
It's a mess, we've run out.
Also something that might not have occurred to you - there is a chilling
effect of limited VMA flag availability - the bar to adding flags is
higher, and features that might have used VMA flags but need general kernel
support (incl. 32-bit) have to find other ways to store state like this.
>
> > Using an integral value doesn't give us any kind of type safety, nor does it
> > give us as easy a means to track what users are doing with flags - both
> > additional benefits of this change.
>
> I tried the below, and it works OK for me with i386:
>
> $ cat bi.c
> #include <stdio.h>
> #include <limits.h>
>
> int main() {
> unsigned _BitInt(128) a = (_BitInt(128))1 << 65;
> unsigned _BitInt(128) b = (_BitInt(128))1 << 66;
>
> printf("a | b == %llx\n", (unsigned long long)((a | b)>>64));
> printf("BITINT_MAXWIDTH == 0x%x\n", BITINT_MAXWIDTH);
>
> return 0;
> }
>
> $ clang -m32 -std=c2x bi.c
> $ ./a.out
> a | b == 6
> BITINT_MAXWIDTH == 0x800000
I'm not sure why you're replying to my points about type safety,
traceability with this program but OK?
I mean thanks for that, I wasn't aware of the c23 standard (proposal?)
_BitInt(). It's useful to know that.
We can't use it right now, but it's good to know for the future.
>
> I didn't make GCC building it, at least out of the box. So the above
> question about 64-bit capacity has a practical meaning. If we've got a
> few years to let GCC fully support big integers as clang does, we don't
> have to wish anything else.
As long as you assume that all architectures will be supported, all
compilers used by users to build the kernel will support it, and Linus will
be fine with us using this.
That could be years, that could be never.
Also - and here's a really important point - the underlying implementation
_doesn't matter_.
Right now it's bitmaps.
By abstracting the VMA flags into an opaque type and providing helper
functions we also enable the ability to _change the implementation_.
So if this time comes, we can simply switch everything over. Job done.
Your suggested 'do nothing and hope' approach achieves none of this.
>
> I'd like to put it right. I maintain bitmaps, and I like it widely
> adopted. But when it comes to flags, being able to use plain logic
> operations looks so important to me so I'd like to make sure that
> switching to bitmaps is the only working option.
I'm not sure you're making a technical argument here?
From the point of view of mm, the ability to arbitrarily manipulate VMA
flags is a bug not a feature. The other part of this series is to make
changes to the f_op->mmap_prepare feature, which was explicitly implemented
in order to avoid such arbitrarily behaviour from drivers.
It's actually hugely valueable to make this change in such a way as we can
trace, with type safety, VMA flag usage throughout the kernel, and know
that for instance - on mmap setup - we don't need to worry about VMA
stabilisation - which feeds into other work re: killable VMA locks.
In summary, this series represents a workable and sensible means of
addressing all of these issues in one fell swoop, similar to the means
through which mm flags were extended across both 32-bit and 64-bit kernels.
We can in future choose to use _BitInt(), u128, or whatever we please
underneath, and which makes sense to use should conditions change and we
choose to do so for good technical reasons.
Any argument on the basis of 'allow the flags to continue to be manipulated
as they are' is I think mistaken.
Keep in mind that bitmap VMA flags are _already_ a merged feature in the
kernel, and this series only works to add sensible helper functions to
manipulate these flags and moves mmap_prepare to using them exclusively.
If we find cases where somehow the compiler does the wrong thing, we
already have functions in mm_types.h that allow us to address the first
system-word bits of the underlying type and can restrict core flags to
being at system word count or less.
I hope that won't ever be necessary, but we have means of adressing that
should any issue arise like that.
Thanks, Lorenzo
^ permalink raw reply
* Re: [PATCH] ipc: don't audit capability check in ipc_permissions()
From: Serge E. Hallyn @ 2026-01-28 3:26 UTC (permalink / raw)
To: Paul Moore
Cc: Serge E. Hallyn, Ondrej Mosnacek, Andrew Morton,
Eric W . Biederman, Alexey Gladkov, linux-kernel,
linux-security-module, selinux
In-Reply-To: <CAHC9VhSLi2-TBUyayML+tAuC+XF7jCAAL48oCB4qQqTrGXcMyA@mail.gmail.com>
On Tue, Jan 27, 2026 at 05:06:47PM -0500, Paul Moore wrote:
> On Mon, Jan 26, 2026 at 9:01 PM Serge E. Hallyn <serge@hallyn.com> wrote:
> > On Mon, Jan 26, 2026 at 05:50:12PM -0500, Paul Moore wrote:
> > > On Thu, Jan 22, 2026 at 9:56 AM Ondrej Mosnacek <omosnace@redhat.com> wrote:
> > > >
> > > > The IPC sysctls implement the ctl_table_root::permissions hook and
> > > > they override the file access mode based on the CAP_CHECKPOINT_RESTORE
> > > > capability, which is being checked regardless of whether any access is
> > > > actually denied or not, so if an LSM denies the capability, an audit
> > > > record may be logged even when access is in fact granted.
> > > >
> > > > It wouldn't be viable to restructure the sysctl permission logic to only
> > > > check the capability when the access would be actually denied if it's
> > > > not granted. Thus, do the same as in net_ctl_permissions()
> > > > (net/sysctl_net.c) - switch from ns_capable() to ns_capable_noaudit(),
> > > > so that the check never emits an audit record.
> > > >
> > > > Fixes: 0889f44e2810 ("ipc: Check permissions for checkpoint_restart sysctls at open time")
> > > > Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
> > > > ---
> > > > include/linux/capability.h | 6 ++++++
> > > > ipc/ipc_sysctl.c | 2 +-
> > > > 2 files changed, 7 insertions(+), 1 deletion(-)
> > >
> > > This change seems reasonable to me, but I would make sure Serge has a
> > > chance to review/ACK this patch as it has a capability impact.
> >
> > Acked-by: Serge Hallyn <serge@hallyn.com>
> >
> > Thanks - looks good to me.
>
> I don't see a dedicated IPC maintainer/tree, do you want to take this
> via the capabilities tree Serge?
Will do.
-serge
^ permalink raw reply
* [PATCH v3 2/3] landlock: add errata documentation section
From: Samasth Norway Ananda @ 2026-01-28 3:18 UTC (permalink / raw)
To: gnoack, mic; +Cc: linux-security-module, linux-kernel, samasth.norway.ananda
In-Reply-To: <20260128031814.2945394-1-samasth.norway.ananda@oracle.com>
[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset=y, Size: 7466 bytes --]
Add errata section with code examples for querying errata and a warning
that most applications should not check errata. Use kernel-doc directives
to include errata descriptions from the header files instead of manual
links.
Also enhance existing DOC sections in security/landlock/errata/abi-*.h
files with Impact sections, and update the code comment in syscalls.c
to remind developers to update errata documentation when applicable.
This addresses the gap where the kernel implements errata tracking
but provides no user-facing documentation on how to use it, while
improving the existing technical documentation in-place rather than
duplicating it.
Signed-off-by: Samasth Norway Ananda <samasth.norway.ananda@oracle.com>
---
Documentation/userspace-api/landlock.rst | 67 ++++++++++++++++++++++--
security/landlock/errata/abi-1.h | 8 +++
security/landlock/errata/abi-4.h | 7 +++
security/landlock/errata/abi-6.h | 10 ++++
security/landlock/syscalls.c | 4 +-
5 files changed, 91 insertions(+), 5 deletions(-)
diff --git a/Documentation/userspace-api/landlock.rst b/Documentation/userspace-api/landlock.rst
index c8ef1392a0c7..405b2d73e699 100644
--- a/Documentation/userspace-api/landlock.rst
+++ b/Documentation/userspace-api/landlock.rst
@@ -8,7 +8,7 @@ Landlock: unprivileged access control
=====================================
:Author: Mickaël Salaün
-:Date: December 2025
+:Date: January 2026
The goal of Landlock is to enable restriction of ambient rights (e.g. global
filesystem or network access) for a set of processes. Because Landlock
@@ -492,9 +492,68 @@ system call:
printf("Landlock supports LANDLOCK_ACCESS_FS_REFER.\n");
}
-The following kernel interfaces are implicitly supported by the first ABI
-version. Features only supported from a specific version are explicitly marked
-as such.
+All Landlock kernel interfaces are supported by the first ABI version unless
+explicitly noted in their documentation.
+
+Landlock errata
+---------------
+
+In addition to ABI versions, Landlock provides an errata mechanism to track
+fixes for issues that may affect backwards compatibility or require userspace
+awareness. The errata bitmask can be queried using:
+
+.. code-block:: c
+
+ int errata;
+
+ errata = landlock_create_ruleset(NULL, 0, LANDLOCK_CREATE_RULESET_ERRATA);
+ if (errata < 0) {
+ /* Landlock not available or disabled */
+ return 0;
+ }
+
+The returned value is a bitmask where each bit represents a specific erratum.
+If bit N is set (``errata & (1 << (N - 1))``), then erratum N has been fixed
+in the running kernel.
+
+.. warning::
+
+ **Most applications should NOT check errata.** In 99.9% of cases, checking
+ errata is unnecessary, increases code complexity, and can potentially
+ decrease protection if misused. For example, disabling the sandbox when an
+ erratum is not fixed could leave the system less secure than using
+ Landlock's best-effort protection. When in doubt, ignore errata.
+
+.. kernel-doc:: security/landlock/errata/abi-4.h
+ :doc: erratum_1
+
+.. kernel-doc:: security/landlock/errata/abi-6.h
+ :doc: erratum_2
+
+.. kernel-doc:: security/landlock/errata/abi-1.h
+ :doc: erratum_3
+
+How to check for errata
+~~~~~~~~~~~~~~~~~~~~~~~
+
+If you determine that your application needs to check for specific errata,
+use this pattern:
+
+.. code-block:: c
+
+ int errata = landlock_create_ruleset(NULL, 0, LANDLOCK_CREATE_RULESET_ERRATA);
+ if (errata >= 0) {
+ /* Check for specific erratum (1-indexed) */
+ if (errata & (1 << (erratum_number - 1))) {
+ /* Erratum N is fixed in this kernel */
+ } else {
+ /* Erratum N is NOT fixed - consider implications for your use case */
+ }
+ }
+
+**Important:** Only check errata if your application specifically relies on
+behavior that changed due to the fix. The fixes generally make Landlock less
+restrictive or more correct, not more restrictive.
Kernel interface
================
diff --git a/security/landlock/errata/abi-1.h b/security/landlock/errata/abi-1.h
index e8a2bff2e5b6..3f099555f059 100644
--- a/security/landlock/errata/abi-1.h
+++ b/security/landlock/errata/abi-1.h
@@ -12,5 +12,13 @@
* hierarchy down to its filesystem root and those from the related mount point
* hierarchy. This prevents access right widening through rename or link
* actions.
+ *
+ * Impact:
+ *
+ * Without this fix, it was possible to widen access rights through rename or
+ * link actions involving disconnected directories, potentially bypassing
+ * ``LANDLOCK_ACCESS_FS_REFER`` restrictions. This could allow privilege
+ * escalation in complex mount scenarios where directories become disconnected
+ * from their original mount points.
*/
LANDLOCK_ERRATUM(3)
diff --git a/security/landlock/errata/abi-4.h b/security/landlock/errata/abi-4.h
index c052ee54f89f..fe11ec7d7ddf 100644
--- a/security/landlock/errata/abi-4.h
+++ b/security/landlock/errata/abi-4.h
@@ -11,5 +11,12 @@
* :manpage:`bind(2)` and :manpage:`connect(2)` operations. This change ensures
* that only TCP sockets are subject to TCP access rights, allowing other
* protocols to operate without unnecessary restrictions.
+ *
+ * Impact:
+ *
+ * In kernels without this fix, using ``LANDLOCK_ACCESS_NET_BIND_TCP`` or
+ * ``LANDLOCK_ACCESS_NET_CONNECT_TCP`` would incorrectly restrict non-TCP
+ * stream protocols (SMC, MPTCP, SCTP), potentially breaking applications
+ * that rely on these protocols while using Landlock network restrictions.
*/
LANDLOCK_ERRATUM(1)
diff --git a/security/landlock/errata/abi-6.h b/security/landlock/errata/abi-6.h
index 5113a829f87e..5cb1475c7ea8 100644
--- a/security/landlock/errata/abi-6.h
+++ b/security/landlock/errata/abi-6.h
@@ -15,5 +15,15 @@
* interaction between threads of the same process should always be allowed.
* This change ensures that any thread is allowed to send signals to any other
* thread within the same process, regardless of their domain.
+ *
+ * Impact:
+ *
+ * This problem only manifests when the userspace process is itself using
+ * :manpage:`libpsx(3)` or an equivalent mechanism to enforce a Landlock policy
+ * on multiple already-running threads at once. Programs which enforce a
+ * Landlock policy at startup time and only then become multithreaded are not
+ * affected. Without this fix, signal scoping could break multi-threaded
+ * applications that expect threads within the same process to freely signal
+ * each other.
*/
LANDLOCK_ERRATUM(2)
diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c
index 8eaec8d35c44..9b7a7f39f26c 100644
--- a/security/landlock/syscalls.c
+++ b/security/landlock/syscalls.c
@@ -158,9 +158,11 @@ static const struct file_operations ruleset_fops = {
/*
* The Landlock ABI version should be incremented for each new Landlock-related
* user space visible change (e.g. Landlock syscalls). This version should
- * only be incremented once per Linux release, and the date in
+ * only be incremented once per Linux release. When incrementing, the date in
* Documentation/userspace-api/landlock.rst should be updated to reflect the
* UAPI change.
+ * If the change involves a fix that requires userspace awareness, also update
+ * the errata documentation in Documentation/userspace-api/landlock.rst.
*/
const int landlock_abi_version = 9;
--
2.50.1
^ permalink raw reply related
* [PATCH v3 3/3] landlock: Document audit blocker field format
From: Samasth Norway Ananda @ 2026-01-28 3:18 UTC (permalink / raw)
To: gnoack, mic; +Cc: linux-security-module, linux-kernel, samasth.norway.ananda
In-Reply-To: <20260128031814.2945394-1-samasth.norway.ananda@oracle.com>
[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset=y, Size: 3176 bytes --]
Add comprehensive documentation for the ``blockers`` field format
in AUDIT_LANDLOCK_ACCESS records, including all possible prefixes
(fs., net., scope.) and their meanings.
Also fix a typo and update the documentation date to reflect these
changes.
Signed-off-by: Samasth Norway Ananda <samasth.norway.ananda@oracle.com>
---
Documentation/admin-guide/LSM/landlock.rst | 35 ++++++++++++++++++++--
1 file changed, 33 insertions(+), 2 deletions(-)
diff --git a/Documentation/admin-guide/LSM/landlock.rst b/Documentation/admin-guide/LSM/landlock.rst
index 9e61607def08..9923874e2156 100644
--- a/Documentation/admin-guide/LSM/landlock.rst
+++ b/Documentation/admin-guide/LSM/landlock.rst
@@ -6,7 +6,7 @@ Landlock: system-wide management
================================
:Author: Mickaël Salaün
-:Date: March 2025
+:Date: January 2026
Landlock can leverage the audit framework to log events.
@@ -38,6 +38,37 @@ AUDIT_LANDLOCK_ACCESS
domain=195ba459b blockers=fs.refer path="/usr/bin" dev="vda2" ino=351
domain=195ba459b blockers=fs.make_reg,fs.refer path="/usr/local" dev="vda2" ino=365
+
+ The ``blockers`` field uses dot-separated prefixes to indicate the type of
+ restriction that caused the denial:
+
+ **fs.*** - Filesystem access rights (ABI 1+):
+ - fs.execute, fs.write_file, fs.read_file, fs.read_dir
+ - fs.remove_dir, fs.remove_file
+ - fs.make_char, fs.make_dir, fs.make_reg, fs.make_sock
+ - fs.make_fifo, fs.make_block, fs.make_sym
+ - fs.refer (ABI 2+)
+ - fs.truncate (ABI 3+)
+ - fs.ioctl_dev (ABI 5+)
+
+ **net.*** - Network access rights (ABI 4+):
+ - net.bind_tcp - TCP port binding was denied
+ - net.connect_tcp - TCP connection was denied
+
+ **scope.*** - IPC scoping restrictions (ABI 6+):
+ - scope.abstract_unix_socket - Abstract UNIX socket connection denied
+ - scope.signal - Signal sending denied
+
+ Multiple blockers can appear in a single event (comma-separated) when
+ multiple access rights are missing. For example, creating a regular file
+ in a directory that lacks both ``make_reg`` and ``refer`` rights would show
+ ``blockers=fs.make_reg,fs.refer``.
+
+ The object identification fields (path, dev, ino for filesystem; opid,
+ ocomm for signals) depend on the type of access being blocked and provide
+ context about what resource was involved in the denial.
+
+
AUDIT_LANDLOCK_DOMAIN
This record type describes the status of a Landlock domain. The ``status``
field can be either ``allocated`` or ``deallocated``.
@@ -86,7 +117,7 @@ This command generates two events, each identified with a unique serial
number following a timestamp (``msg=audit(1729738800.268:30)``). The first
event (serial ``30``) contains 4 records. The first record
(``type=LANDLOCK_ACCESS``) shows an access denied by the domain `1a6fdc66f`.
-The cause of this denial is signal scopping restriction
+The cause of this denial is signal scoping restriction
(``blockers=scope.signal``). The process that would have receive this signal
is the init process (``opid=1 ocomm="systemd"``).
--
2.50.1
^ permalink raw reply related
* [PATCH v3 0/3] landlock: documentation improvements
From: Samasth Norway Ananda @ 2026-01-28 3:18 UTC (permalink / raw)
To: gnoack, mic; +Cc: linux-security-module, linux-kernel, samasth.norway.ananda
This patch series improves Landlock documentation by addressing gaps in
ABI compatibility examples, adding errata documentation, and documenting
the audit blockers field format.
Changes since v2:
=================
Patch 1/3:
- Handle restrict_flags in a separate code block, not in the switch
- Clear all three ABI v7 logging flags for a generic example
- Reference sys_landlock_restrict_self() for available flags
- Use restrict_flags in landlock_restrict_self()
Patch 2/3:
- Use kernel-doc directives to include errata from header files
- Move rephrased ABI version text before errata section
Patch 3/3:
- No changes
Changes since v1:
=================
Patch 1/3:
- Add backwards compatibility section for restrict flags
- Fix /usr rule description
Patch 2/3:
- Enhance existing DOC sections with Impact descriptions
- Add errata usage documentation
Patch 3/3:
- Document audit blocker field format
Samasth Norway Ananda (3):
landlock: add backwards compatibility for restrict flags
landlock: add errata documentation section
landlock: document audit blockers field format
Documentation/admin-guide/LSM/landlock.rst | 20 ++++-
Documentation/userspace-api/landlock.rst | 97 +++++++++++++++++++---
security/landlock/errata/abi-1.h | 8 ++
security/landlock/errata/abi-4.h | 7 ++
security/landlock/errata/abi-6.h | 10 +++
security/landlock/syscalls.c | 4 +-
6 files changed, 131 insertions(+), 15 deletions(-)
--
2.50.1
^ permalink raw reply
* [PATCH v3 1/3] landlock: add backwards compatibility for restrict flags
From: Samasth Norway Ananda @ 2026-01-28 3:18 UTC (permalink / raw)
To: gnoack, mic; +Cc: linux-security-module, linux-kernel, samasth.norway.ananda
In-Reply-To: <20260128031814.2945394-1-samasth.norway.ananda@oracle.com>
Add backwards compatibility handling for the restrict flags introduced
in ABI version 7. This is shown as a separate code block (similar to
the ruleset_attr handling in the switch statement) because restrict flags
are passed to landlock_restrict_self() rather than being part of the
ruleset attributes.
Also fix misleading description of the /usr rule which incorrectly
stated it "only allow[s] reading" when the code actually allows both
reading and executing (LANDLOCK_ACCESS_FS_EXECUTE is included in
allowed_access).
Signed-off-by: Samasth Norway Ananda <samasth.norway.ananda@oracle.com>
---
Documentation/userspace-api/landlock.rst | 30 +++++++++++++++++-------
1 file changed, 22 insertions(+), 8 deletions(-)
diff --git a/Documentation/userspace-api/landlock.rst b/Documentation/userspace-api/landlock.rst
index 1ed25af0499f..c8ef1392a0c7 100644
--- a/Documentation/userspace-api/landlock.rst
+++ b/Documentation/userspace-api/landlock.rst
@@ -157,11 +157,11 @@ This enables the creation of an inclusive ruleset that will contain our rules.
}
We can now add a new rule to this ruleset thanks to the returned file
-descriptor referring to this ruleset. The rule will only allow reading the
-file hierarchy ``/usr``. Without another rule, write actions would then be
-denied by the ruleset. To add ``/usr`` to the ruleset, we open it with the
-``O_PATH`` flag and fill the &struct landlock_path_beneath_attr with this file
-descriptor.
+descriptor referring to this ruleset. The rule will allow reading and
+executing the file hierarchy ``/usr``. Without another rule, write actions
+would then be denied by the ruleset. To add ``/usr`` to the ruleset, we open
+it with the ``O_PATH`` flag and fill the &struct landlock_path_beneath_attr with
+this file descriptor.
.. code-block:: c
@@ -233,10 +233,24 @@ to effectively block sending UDP datagrams to arbitrary ports.
err = landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_PORT,
&net_port, 0);
+When passing a non-zero ``flags`` argument to ``landlock_restrict_self()``, a
+similar backwards compatibility check is needed for the restrict flags
+(see sys_landlock_restrict_self() documentation for available flags):
+
+.. code-block:: c
+
+ __u32 restrict_flags = LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON;
+ if (abi < 7) {
+ /* Clear logging flags unsupported before ABI 7. */
+ restrict_flags &= ~(LANDLOCK_RESTRICT_SELF_LOG_SAME_EXEC_OFF |
+ LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON |
+ LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF);
+ }
+
The next step is to restrict the current thread from gaining more privileges
(e.g. through a SUID binary). We now have a ruleset with the first rule
-allowing read access to ``/usr`` while denying all other handled accesses for
-the filesystem, and two more rules allowing DNS queries.
+allowing read and execute access to ``/usr`` while denying all other handled
+accesses for the filesystem, and two more rules allowing DNS queries.
.. code-block:: c
@@ -250,7 +264,7 @@ The current thread is now ready to sandbox itself with the ruleset.
.. code-block:: c
- if (landlock_restrict_self(ruleset_fd, 0)) {
+ if (landlock_restrict_self(ruleset_fd, restrict_flags)) {
perror("Failed to enforce ruleset");
close(ruleset_fd);
return 1;
--
2.50.1
^ permalink raw reply related
* Re: [PATCH] ucount: check for CAP_SYS_RESOURCE using ns_capable_noaudit()
From: Paul Moore @ 2026-01-27 22:09 UTC (permalink / raw)
To: Andrew Morton
Cc: Ondrej Mosnacek, Serge E. Hallyn, Eric W . Biederman,
linux-kernel, linux-security-module, selinux
In-Reply-To: <CAFqZXNve_7oKFWydUrskOcvsfbRZVKyWRmLvHKsTzBhG+RmEmQ@mail.gmail.com>
On Tue, Jan 27, 2026 at 3:05 AM Ondrej Mosnacek <omosnace@redhat.com> wrote:
>
> On Tue, Jan 27, 2026 at 2:55 AM Serge E. Hallyn <serge@hallyn.com> wrote:
> >
> > On Mon, Jan 26, 2026 at 05:52:03PM -0500, Paul Moore wrote:
> > > On Thu, Jan 22, 2026 at 9:25 AM Ondrej Mosnacek <omosnace@redhat.com> wrote:
> > > >
> > > > The user.* sysctls implement the ctl_table_root::permissions hook and
> > > > they override the file access mode based on the CAP_SYS_RESOURCE
> > > > capability (at most rwx if capable, at most r-- if not). The capability
> > > > is being checked unconditionally, so if an LSM denies the capability, an
> > > > audit record may be logged even when access is in fact granted.
> > > >
> > > > Given the logic in the set_permissions() function in kernel/ucount.c and
> > > > the unfortunate way the permission checking is implemented, it doesn't
> > > > seem viable to avoid false positive denials by deferring the capability
> > > > check. Thus, do the same as in net_ctl_permissions() (net/sysctl_net.c)
> > > > - switch from ns_capable() to ns_capable_noaudit(), so that the check
> > > > never logs an audit record.
> > > >
> > > > Fixes: dbec28460a89 ("userns: Add per user namespace sysctls.")
> > > > Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
> > > > ---
> > > > kernel/ucount.c | 2 +-
> > > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > Reviewed-by: Paul Moore <paul@paul-moore.com>
> >
> > Acked-by: Serge Hallyn <serge@hallyn.com>
> >
> > Looks good to me. What tree should this go through? Network?
>
> Andrew has already applied the two patches I posted into his
> mm-nonmm-unstable branch, so I assume they are set to go through his
> tree.
Andrew, any chance we can get a reply to these threads when you merge
a patch into your tree?
--
paul-moore.com
^ permalink raw reply
* Re: [PATCH] ipc: don't audit capability check in ipc_permissions()
From: Paul Moore @ 2026-01-27 22:06 UTC (permalink / raw)
To: Serge E. Hallyn
Cc: Ondrej Mosnacek, Andrew Morton, Eric W . Biederman,
Alexey Gladkov, linux-kernel, linux-security-module, selinux
In-Reply-To: <aXgcd81ktMaAHhwj@mail.hallyn.com>
On Mon, Jan 26, 2026 at 9:01 PM Serge E. Hallyn <serge@hallyn.com> wrote:
> On Mon, Jan 26, 2026 at 05:50:12PM -0500, Paul Moore wrote:
> > On Thu, Jan 22, 2026 at 9:56 AM Ondrej Mosnacek <omosnace@redhat.com> wrote:
> > >
> > > The IPC sysctls implement the ctl_table_root::permissions hook and
> > > they override the file access mode based on the CAP_CHECKPOINT_RESTORE
> > > capability, which is being checked regardless of whether any access is
> > > actually denied or not, so if an LSM denies the capability, an audit
> > > record may be logged even when access is in fact granted.
> > >
> > > It wouldn't be viable to restructure the sysctl permission logic to only
> > > check the capability when the access would be actually denied if it's
> > > not granted. Thus, do the same as in net_ctl_permissions()
> > > (net/sysctl_net.c) - switch from ns_capable() to ns_capable_noaudit(),
> > > so that the check never emits an audit record.
> > >
> > > Fixes: 0889f44e2810 ("ipc: Check permissions for checkpoint_restart sysctls at open time")
> > > Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
> > > ---
> > > include/linux/capability.h | 6 ++++++
> > > ipc/ipc_sysctl.c | 2 +-
> > > 2 files changed, 7 insertions(+), 1 deletion(-)
> >
> > This change seems reasonable to me, but I would make sure Serge has a
> > chance to review/ACK this patch as it has a capability impact.
>
> Acked-by: Serge Hallyn <serge@hallyn.com>
>
> Thanks - looks good to me.
I don't see a dedicated IPC maintainer/tree, do you want to take this
via the capabilities tree Serge?
--
paul-moore.com
^ permalink raw reply
* Re: [PATCH] xfrm: kill xfrm_dev_{state,policy}_flush_secctx_check()
From: Paul Moore @ 2026-01-27 21:59 UTC (permalink / raw)
To: Tetsuo Handa
Cc: SELinux, linux-security-module, Steffen Klassert, Herbert Xu,
David S. Miller, Eric Dumazet, Jakub Kicinski, Paolo Abeni,
Simon Horman, Network Development
In-Reply-To: <00ed59a3-a9c9-47c3-97da-5a8e3da1ea82@I-love.SAKURA.ne.jp>
On Mon, Jan 26, 2026 at 10:51 PM Tetsuo Handa
<penguin-kernel@i-love.sakura.ne.jp> wrote:
> On 2026/01/27 7:33, Paul Moore wrote:
> > On Fri, Jan 23, 2026 at 5:13 AM Tetsuo Handa
> > <penguin-kernel@i-love.sakura.ne.jp> wrote:
> >>
> >> Since xfrm_dev_{state,policy}_flush() are called from only NETDEV_DOWN and
> >> NETDEV_UNREGISTER events, making xfrm_dev_{state,policy}_flush() no-op by
> >> returning an error value from xfrm_dev_{state,policy}_flush_secctx_check()
> >> is pointless. Especially, if xfrm_dev_{state,policy}_flush_secctx_check()
> >> returned an error value upon NETDEV_UNREGISTER event, the system will hung
> >> up with
> >>
> >> unregister_netdevice: waiting for $dev to become free. Usage count = $count
> >>
> >> message because the reference to $dev acquired by
> >> xfrm_dev_{state,policy}_add() cannot be released.
> >>
> >> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> >> ---
> >> net/xfrm/xfrm_policy.c | 35 -----------------------------------
> >> net/xfrm/xfrm_state.c | 33 ---------------------------------
> >> 2 files changed, 68 deletions(-)
> >
> > I didn't make it very far into reviewing this patch, because it looks
> > like xfrm_dev_state_flush() is called by the bonding driver's
> > notification handler, and I don't see that reflected in this patch?
>
> xfrm_dev_{state,policy}_flush() are called from only ...
My apologies, I was looking at the patch too quickly and shortened
xfrm_dev_state_flush_secctx_check() into xfrm_dev_state_flush() when
looking at the callers.
> LSM hook for checking whether to allow deleting a file in tmpfs which is still mounted
> makes sense, LSM hook for checking whether to allow starting unmount of tmpfs makes sense,
> but LSM hook for checking whether to allow releasing memory in tmpfs while unmount operation
> is already in progress causes nothing but a resource leak / denial-of-service kernel bug.
>
> What xfrm_dev_{state,policy}_flush_secctx_check() are causing is something like
> "LSM policy is refusing release of memory used by a file in tmpfs which is already under
> unmount operation".
> xfrm_dev_{state,policy}_flush_secctx_check() are too late to make LSM policy decision.
> A must-not-fail operation has already started before LSM hooks are called.
It sounds like we either need to confirm that
security_xfrm_{policy,state}_delete() is already present in all code
paths that result in SPD/SAD deletions (in a place that can safely
fail and return an error), or we need to place
xfrm_dev_{policy,state}_flush_secctx_check() in a location that can
safely fail. The patch doesn't relocate
xfrm_dev_{policy,state}_flush_secctx_check() and I don't really see
any mention about security_xfrm_{policy,state}_delete() in the patch
or description; have you verified that the LSM xfrm hooks are still
being called to authorize the removals?
--
paul-moore.com
^ permalink raw reply
* Re: [PATCH v2 00/13] mm: add bitmap VMA flag helpers and convert all mmap_prepare to use them
From: Yury Norov @ 2026-01-27 21:36 UTC (permalink / raw)
To: Lorenzo Stoakes
Cc: Andrew Morton, Jarkko Sakkinen, Dave Hansen, Thomas Gleixner,
Ingo Molnar, Borislav Petkov, x86, H . Peter Anvin, Arnd Bergmann,
Greg Kroah-Hartman, Dan Williams, Vishal Verma, Dave Jiang,
Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, David Airlie,
Simona Vetter, Jani Nikula, Joonas Lahtinen, Rodrigo Vivi,
Tvrtko Ursulin, Christian Koenig, Huang Rui, Matthew Auld,
Matthew Brost, Alexander Viro, Christian Brauner, Jan Kara,
Benjamin LaHaise, Gao Xiang, Chao Yu, Yue Hu, Jeffle Xu,
Sandeep Dhavale, Hongbo Li, Chunhai Guo, Theodore Ts'o,
Andreas Dilger, Muchun Song, Oscar Salvador, David Hildenbrand,
Konstantin Komarov, Mike Marshall, Martin Brandenburg, Tony Luck,
Reinette Chatre, Dave Martin, James Morse, Babu Moger,
Carlos Maiolino, Damien Le Moal, Naohiro Aota, Johannes Thumshirn,
Matthew Wilcox, Liam R . Howlett, Vlastimil Babka, Mike Rapoport,
Suren Baghdasaryan, Michal Hocko, Hugh Dickins, Baolin Wang,
Zi Yan, Nico Pache, Ryan Roberts, Dev Jain, Barry Song,
Lance Yang, Jann Horn, Pedro Falcato, David Howells, Paul Moore,
James Morris, Serge E . Hallyn, Yury Norov, Rasmus Villemoes,
linux-sgx, linux-kernel, nvdimm, linux-cxl, dri-devel, intel-gfx,
linux-fsdevel, linux-aio, linux-erofs, linux-ext4, linux-mm,
ntfs3, devel, linux-xfs, keyrings, linux-security-module,
Jason Gunthorpe
In-Reply-To: <5f764622-fd45-4c49-8ecb-7dc4d1fa48d6@lucifer.local>
On Tue, Jan 27, 2026 at 02:40:03PM +0000, Lorenzo Stoakes wrote:
> On Tue, Jan 27, 2026 at 08:53:44AM -0500, Yury Norov wrote:
> > On Thu, Jan 22, 2026 at 04:06:09PM +0000, Lorenzo Stoakes wrote:
...
> > Even if you expect adding more flags, u128 would double your capacity,
> > and people will still be able to use language-supported operation on
> > the bits in flag. Which looks simpler to me...
>
> u128 isn't supported on all architectures, VMA flags have to have absolutely
What about big integers?
typedef unsigned _BitInt(VMA_FLAGS_COUNT) vma_flags_t
> We want to be able to arbitrarily extend this as we please in the future. So
> using u64 wouldn't buy us _anything_ except getting the 32-bit kernels in line.
So enabling 32-bit arches is a big deal, even if it's a temporary
solution. Again, how many flags in your opinion are blocked because of
32-bit integer limitation? How soon 64-bit capacity will get fully
used?
> Using an integral value doesn't give us any kind of type safety, nor does it
> give us as easy a means to track what users are doing with flags - both
> additional benefits of this change.
I tried the below, and it works OK for me with i386:
$ cat bi.c
#include <stdio.h>
#include <limits.h>
int main() {
unsigned _BitInt(128) a = (_BitInt(128))1 << 65;
unsigned _BitInt(128) b = (_BitInt(128))1 << 66;
printf("a | b == %llx\n", (unsigned long long)((a | b)>>64));
printf("BITINT_MAXWIDTH == 0x%x\n", BITINT_MAXWIDTH);
return 0;
}
$ clang -m32 -std=c2x bi.c
$ ./a.out
a | b == 6
BITINT_MAXWIDTH == 0x800000
I didn't make GCC building it, at least out of the box. So the above
question about 64-bit capacity has a practical meaning. If we've got a
few years to let GCC fully support big integers as clang does, we don't
have to wish anything else.
I'd like to put it right. I maintain bitmaps, and I like it widely
adopted. But when it comes to flags, being able to use plain logic
operations looks so important to me so I'd like to make sure that
switching to bitmaps is the only working option.
^ permalink raw reply
* Re: [PATCH v3] ima_fs: Avoid creating measurement lists for unsupported hash algos
From: Jonathan McDowell @ 2026-01-27 17:59 UTC (permalink / raw)
To: dima
Cc: Mimi Zohar, Roberto Sassu, Dmitry Kasatkin, Eric Snowberg,
Paul Moore, James Morris, Serge E. Hallyn, Silvia Sisinni,
Enrico Bravi, linux-integrity, linux-security-module,
linux-kernel, stable, Dmitry Safonov
In-Reply-To: <20260127-ima-oob-v3-1-1dd09f4c2a6a@arista.com>
On Tue, Jan 27, 2026 at 02:21:13PM +0000, Dmitry Safonov via B4 Relay wrote:
>From: Dmitry Safonov <dima@arista.com>
>
>ima_init_crypto() skips initializing ima_algo_array[i] if the algorithm
>from ima_tpm_chip->allocated_banks[i].crypto_id is not supported.
>It seems avoid adding the unsupported algorithm to ima_algo_array will
>break all the logic that relies on indexing by NR_BANKS(ima_tpm_chip).
>
>On 6.12.40 I observe the following read out-of-bounds in hash_algo_name:
>
>> ==================================================================
>> BUG: KASAN: global-out-of-bounds in create_securityfs_measurement_lists+0x396/0x440
>> Read of size 8 at addr ffffffff83e18138 by task swapper/0/1
>>
>> CPU: 4 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.40 #3
>> Call Trace:
>> <TASK>
>> dump_stack_lvl+0x61/0x90
>> print_report+0xc4/0x580
>> ? kasan_addr_to_slab+0x26/0x80
>> ? create_securityfs_measurement_lists+0x396/0x440
>> kasan_report+0xc2/0x100
>> ? create_securityfs_measurement_lists+0x396/0x440
>> create_securityfs_measurement_lists+0x396/0x440
>> ima_fs_init+0xa3/0x300
>> ima_init+0x7d/0xd0
>> init_ima+0x28/0x100
>> do_one_initcall+0xa6/0x3e0
>> kernel_init_freeable+0x455/0x740
>> kernel_init+0x24/0x1d0
>> ret_from_fork+0x38/0x80
>> ret_from_fork_asm+0x11/0x20
>> </TASK>
>>
>> The buggy address belongs to the variable:
>> hash_algo_name+0xb8/0x420
>>
>> The buggy address belongs to the physical page:
>> page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x107ce18
>> flags: 0x8000000000002000(reserved|zone=2)
>> raw: 8000000000002000 ffffea0041f38608 ffffea0041f38608 0000000000000000
>> raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
>> page dumped because: kasan: bad access detected
>>
>> Memory state around the buggy address:
>> ffffffff83e18000: 00 01 f9 f9 f9 f9 f9 f9 00 01 f9 f9 f9 f9 f9 f9
>> ffffffff83e18080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>> >ffffffff83e18100: 00 00 00 00 00 00 00 f9 f9 f9 f9 f9 00 05 f9 f9
>> ^
>> ffffffff83e18180: f9 f9 f9 f9 00 00 00 00 00 00 00 04 f9 f9 f9 f9
>> ffffffff83e18200: 00 00 00 00 00 00 00 00 04 f9 f9 f9 f9 f9 f9 f9
>> ==================================================================
>
>Seems like the TPM chip supports sha3_256, which isn't yet in
>tpm_algorithms:
>> tpm tpm0: TPM with unsupported bank algorithm 0x0027
>
>Grepping HASH_ALGO__LAST in security/integrity/ima/ shows that is
>the check other logic relies on, so add files under TPM_ALG_<ID>
>and print 0 as their hash_digest_size.
Can I suggest, for better consistency, it's tpm_alg_<id> (i.e. lower
case, like the rest of the path)?
>This is how it looks on the test machine I have:
>> # ls -1 /sys/kernel/security/ima/
>> ascii_runtime_measurements
>> ascii_runtime_measurements_TPM_ALG_27
>> ascii_runtime_measurements_sha1
>> ascii_runtime_measurements_sha256
>> binary_runtime_measurements
>> binary_runtime_measurements_TPM_ALG_27
>> binary_runtime_measurements_sha1
>> binary_runtime_measurements_sha256
>> policy
>> runtime_measurements_count
>> violations
J.
--
"Why 'maybe' for everything?" "I'm using fluffy logic."
^ permalink raw reply
* Re: [PATCH v4] ima_fs: Avoid creating measurement lists for unsupported hash algos
From: Roberto Sassu @ 2026-01-27 15:20 UTC (permalink / raw)
To: dima, Mimi Zohar, Roberto Sassu, Dmitry Kasatkin, Eric Snowberg,
Paul Moore, James Morris, Serge E. Hallyn, Silvia Sisinni,
Enrico Bravi
Cc: linux-integrity, linux-security-module, linux-kernel, stable,
Dmitry Safonov
In-Reply-To: <20260127-ima-oob-v4-1-bf0cd7f9b4d4@arista.com>
On Tue, 2026-01-27 at 15:03 +0000, Dmitry Safonov via B4 Relay wrote:
> From: Dmitry Safonov <dima@arista.com>
>
> ima_init_crypto() skips initializing ima_algo_array[i] if the algorithm
> from ima_tpm_chip->allocated_banks[i].crypto_id is not supported.
> It seems avoid adding the unsupported algorithm to ima_algo_array will
> break all the logic that relies on indexing by NR_BANKS(ima_tpm_chip).
The patch looks good, although I didn't try yet myself.
I would make the commit message slightly better, with a more fluid
explanation.
ima_tpm_chip->allocated_banks[i].crypto_id is initialized to
HASH_ALGO__LAST if the TPM algorithm is not supported. However there
are places relying on the algorithm to be valid because it is accessed
by hash_algo_name[].
Thus solve the problem by creating a file name that does not depend on
the crypto algorithm to be initialized, ...
Also print the template entry digest as populated by IMA.
Something along these lines.
Also, I have a preference for lower case instead of capital case for
the file name, given the other names.
Could you also avoid the >, otherwise the mailer thinks it is a reply?
Thanks
Roberto
> On 6.12.40 I observe the following read out-of-bounds in hash_algo_name:
>
> > ==================================================================
> > BUG: KASAN: global-out-of-bounds in create_securityfs_measurement_lists+0x396/0x440
> > Read of size 8 at addr ffffffff83e18138 by task swapper/0/1
> >
> > CPU: 4 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.40 #3
> > Call Trace:
> > <TASK>
> > dump_stack_lvl+0x61/0x90
> > print_report+0xc4/0x580
> > ? kasan_addr_to_slab+0x26/0x80
> > ? create_securityfs_measurement_lists+0x396/0x440
> > kasan_report+0xc2/0x100
> > ? create_securityfs_measurement_lists+0x396/0x440
> > create_securityfs_measurement_lists+0x396/0x440
> > ima_fs_init+0xa3/0x300
> > ima_init+0x7d/0xd0
> > init_ima+0x28/0x100
> > do_one_initcall+0xa6/0x3e0
> > kernel_init_freeable+0x455/0x740
> > kernel_init+0x24/0x1d0
> > ret_from_fork+0x38/0x80
> > ret_from_fork_asm+0x11/0x20
> > </TASK>
> >
> > The buggy address belongs to the variable:
> > hash_algo_name+0xb8/0x420
> >
> > The buggy address belongs to the physical page:
> > page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x107ce18
> > flags: 0x8000000000002000(reserved|zone=2)
> > raw: 8000000000002000 ffffea0041f38608 ffffea0041f38608 0000000000000000
> > raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
> > page dumped because: kasan: bad access detected
> >
> > Memory state around the buggy address:
> > ffffffff83e18000: 00 01 f9 f9 f9 f9 f9 f9 00 01 f9 f9 f9 f9 f9 f9
> > ffffffff83e18080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > > ffffffff83e18100: 00 00 00 00 00 00 00 f9 f9 f9 f9 f9 00 05 f9 f9
> > ^
> > ffffffff83e18180: f9 f9 f9 f9 00 00 00 00 00 00 00 04 f9 f9 f9 f9
> > ffffffff83e18200: 00 00 00 00 00 00 00 00 04 f9 f9 f9 f9 f9 f9 f9
> > ==================================================================
>
> Seems like the TPM chip supports sha3_256, which isn't yet in
> tpm_algorithms:
> > tpm tpm0: TPM with unsupported bank algorithm 0x0027
>
> Use TPM_ALG_<ID> as a postfix for file names for unsupported hashing algorithms.
>
> This is how it looks on the test machine I have:
> > # ls -1 /sys/kernel/security/ima/
> > ascii_runtime_measurements
> > ascii_runtime_measurements_TPM_ALG_27
> > ascii_runtime_measurements_sha1
> > ascii_runtime_measurements_sha256
> > binary_runtime_measurements
> > binary_runtime_measurements_TPM_ALG_27
> > binary_runtime_measurements_sha1
> > binary_runtime_measurements_sha256
> > policy
> > runtime_measurements_count
> > violations
>
> Fixes: 9fa8e7625008 ("ima: add crypto agility support for template-hash algorithm")
> Signed-off-by: Dmitry Safonov <dima@arista.com>
> Cc: Enrico Bravi <enrico.bravi@polito.it>
> Cc: Silvia Sisinni <silvia.sisinni@polito.it>
> Cc: Roberto Sassu <roberto.sassu@huawei.com>
> Cc: Mimi Zohar <zohar@linux.ibm.com>
> ---
> Changes in v4:
> - Use ima_tpm_chip->allocated_banks[algo_idx].digest_size instead of hash_digest_size[algo]
> (Roberto Sassu)
> - Link to v3: https://lore.kernel.org/r/20260127-ima-oob-v3-1-1dd09f4c2a6a@arista.com
> Testing note: I test it on v6.12.40 kernel backport, which slightly differs as
> lookup_template_data_hash_algo() was yet present.
>
> Changes in v3:
> - Now fix the spelling *for real* (sorry, messed it up in v2)
> - Link to v2: https://lore.kernel.org/r/20260127-ima-oob-v2-1-f38a18c850cf@arista.com
>
> Changes in v2:
> - Instead of skipping unknown algorithms, add files under their TPM_ALG_ID (Roberto Sassu)
> - Fix spelling (Roberto Sassu)
> - Copy @stable on the fix
> - Link to v1: https://lore.kernel.org/r/20260127-ima-oob-v1-1-2d42f3418e57@arista.com
> ---
> security/integrity/ima/ima_fs.c | 34 ++++++++++++++++++----------------
> 1 file changed, 18 insertions(+), 16 deletions(-)
>
> diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
> index 012a58959ff0..9a00a0547619 100644
> --- a/security/integrity/ima/ima_fs.c
> +++ b/security/integrity/ima/ima_fs.c
> @@ -132,16 +132,12 @@ int ima_measurements_show(struct seq_file *m, void *v)
> char *template_name;
> u32 pcr, namelen, template_data_len; /* temporary fields */
> bool is_ima_template = false;
> - enum hash_algo algo;
> int i, algo_idx;
>
> algo_idx = ima_sha1_idx;
> - algo = HASH_ALGO_SHA1;
>
> - if (m->file != NULL) {
> + if (m->file != NULL)
> algo_idx = (unsigned long)file_inode(m->file)->i_private;
> - algo = ima_algo_array[algo_idx].algo;
> - }
>
> /* get entry */
> e = qe->entry;
> @@ -160,7 +156,8 @@ int ima_measurements_show(struct seq_file *m, void *v)
> ima_putc(m, &pcr, sizeof(e->pcr));
>
> /* 2nd: template digest */
> - ima_putc(m, e->digests[algo_idx].digest, hash_digest_size[algo]);
> + ima_putc(m, e->digests[algo_idx].digest,
> + ima_tpm_chip->allocated_banks[algo_idx].digest_size);
>
> /* 3rd: template name size */
> namelen = !ima_canonical_fmt ? strlen(template_name) :
> @@ -229,16 +226,12 @@ static int ima_ascii_measurements_show(struct seq_file *m, void *v)
> struct ima_queue_entry *qe = v;
> struct ima_template_entry *e;
> char *template_name;
> - enum hash_algo algo;
> int i, algo_idx;
>
> algo_idx = ima_sha1_idx;
> - algo = HASH_ALGO_SHA1;
>
> - if (m->file != NULL) {
> + if (m->file != NULL)
> algo_idx = (unsigned long)file_inode(m->file)->i_private;
> - algo = ima_algo_array[algo_idx].algo;
> - }
>
> /* get entry */
> e = qe->entry;
> @@ -252,7 +245,8 @@ static int ima_ascii_measurements_show(struct seq_file *m, void *v)
> seq_printf(m, "%2d ", e->pcr);
>
> /* 2nd: template hash */
> - ima_print_digest(m, e->digests[algo_idx].digest, hash_digest_size[algo]);
> + ima_print_digest(m, e->digests[algo_idx].digest,
> + ima_tpm_chip->allocated_banks[algo_idx].digest_size);
>
> /* 3th: template name */
> seq_printf(m, " %s", template_name);
> @@ -404,16 +398,24 @@ static int __init create_securityfs_measurement_lists(void)
> char file_name[NAME_MAX + 1];
> struct dentry *dentry;
>
> - sprintf(file_name, "ascii_runtime_measurements_%s",
> - hash_algo_name[algo]);
> + if (algo == HASH_ALGO__LAST)
> + sprintf(file_name, "ascii_runtime_measurements_TPM_ALG_%x",
> + ima_tpm_chip->allocated_banks[i].alg_id);
> + else
> + sprintf(file_name, "ascii_runtime_measurements_%s",
> + hash_algo_name[algo]);
> dentry = securityfs_create_file(file_name, S_IRUSR | S_IRGRP,
> ima_dir, (void *)(uintptr_t)i,
> &ima_ascii_measurements_ops);
> if (IS_ERR(dentry))
> return PTR_ERR(dentry);
>
> - sprintf(file_name, "binary_runtime_measurements_%s",
> - hash_algo_name[algo]);
> + if (algo == HASH_ALGO__LAST)
> + sprintf(file_name, "binary_runtime_measurements_TPM_ALG_%x",
> + ima_tpm_chip->allocated_banks[i].alg_id);
> + else
> + sprintf(file_name, "binary_runtime_measurements_%s",
> + hash_algo_name[algo]);
> dentry = securityfs_create_file(file_name, S_IRUSR | S_IRGRP,
> ima_dir, (void *)(uintptr_t)i,
> &ima_measurements_ops);
>
> ---
> base-commit: 63804fed149a6750ffd28610c5c1c98cce6bd377
> change-id: 20260127-ima-oob-9fa83a634d7b
>
> Best regards,
^ permalink raw reply
* Re: [PATCH v4 08/17] module: Deduplicate signature extraction
From: Petr Pavlu @ 2026-01-27 15:20 UTC (permalink / raw)
To: Thomas Weißschuh
Cc: Nathan Chancellor, Arnd Bergmann, Luis Chamberlain, Sami Tolvanen,
Daniel Gomez, Paul Moore, James Morris, Serge E. Hallyn,
Jonathan Corbet, Madhavan Srinivasan, Michael Ellerman,
Nicholas Piggin, Naveen N Rao, Mimi Zohar, Roberto Sassu,
Dmitry Kasatkin, Eric Snowberg, Nicolas Schier, Daniel Gomez,
Aaron Tomlin, Christophe Leroy (CS GROUP), Nicolas Schier,
Nicolas Bouchinet, Xiu Jianfeng, Fabian Grünbichler,
Arnout Engelen, Mattia Rizzolo, kpcyrd, Christian Heusel,
Câju Mihai-Drosi, Sebastian Andrzej Siewior, linux-kbuild,
linux-kernel, linux-arch, linux-modules, linux-security-module,
linux-doc, linuxppc-dev, linux-integrity
In-Reply-To: <20260113-module-hashes-v4-8-0b932db9b56b@weissschuh.net>
On 1/13/26 1:28 PM, Thomas Weißschuh wrote:
> The logic to extract the signature bits from a module file are
> duplicated between the module core and IMA modsig appraisal.
>
> Unify the implementation.
>
> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
> ---
> include/linux/module_signature.h | 4 +--
> kernel/module/signing.c | 52 +++++++------------------------------
> kernel/module_signature.c | 41 +++++++++++++++++++++++++++--
> security/integrity/ima/ima_modsig.c | 24 ++++-------------
> 4 files changed, 56 insertions(+), 65 deletions(-)
>
> diff --git a/include/linux/module_signature.h b/include/linux/module_signature.h
> index 7eb4b00381ac..186a55effa30 100644
> --- a/include/linux/module_signature.h
> +++ b/include/linux/module_signature.h
> @@ -40,7 +40,7 @@ struct module_signature {
> __be32 sig_len; /* Length of signature data */
> };
>
> -int mod_check_sig(const struct module_signature *ms, size_t file_len,
> - const char *name);
> +int mod_split_sig(const void *buf, size_t *buf_len, bool mangled,
> + size_t *sig_len, const u8 **sig, const char *name);
>
> #endif /* _LINUX_MODULE_SIGNATURE_H */
> diff --git a/kernel/module/signing.c b/kernel/module/signing.c
> index fe3f51ac6199..6d64c0d18d0a 100644
> --- a/kernel/module/signing.c
> +++ b/kernel/module/signing.c
> @@ -37,54 +37,22 @@ void set_module_sig_enforced(void)
> sig_enforce = true;
> }
>
> -/*
> - * Verify the signature on a module.
> - */
> -static int mod_verify_sig(const void *mod, struct load_info *info)
> -{
> - struct module_signature ms;
> - size_t sig_len, modlen = info->len;
> - int ret;
> -
> - pr_devel("==>%s(,%zu)\n", __func__, modlen);
> -
> - if (modlen <= sizeof(ms))
> - return -EBADMSG;
> -
> - memcpy(&ms, mod + (modlen - sizeof(ms)), sizeof(ms));
> -
> - ret = mod_check_sig(&ms, modlen, "module");
> - if (ret)
> - return ret;
> -
> - sig_len = be32_to_cpu(ms.sig_len);
> - modlen -= sig_len + sizeof(ms);
> - info->len = modlen;
> -
> - return verify_pkcs7_signature(mod, modlen, mod + modlen, sig_len,
> - VERIFY_USE_SECONDARY_KEYRING,
> - VERIFYING_MODULE_SIGNATURE,
> - NULL, NULL);
> -}
> -
> int module_sig_check(struct load_info *info, int flags)
> {
> - int err = -ENODATA;
> - const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
> + int err;
> const char *reason;
> const void *mod = info->hdr;
> + size_t sig_len;
> + const u8 *sig;
> bool mangled_module = flags & (MODULE_INIT_IGNORE_MODVERSIONS |
> MODULE_INIT_IGNORE_VERMAGIC);
> - /*
> - * Do not allow mangled modules as a module with version information
> - * removed is no longer the module that was signed.
> - */
> - if (!mangled_module &&
> - info->len > markerlen &&
> - memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
> - /* We truncate the module to discard the signature */
> - info->len -= markerlen;
> - err = mod_verify_sig(mod, info);
> +
> + err = mod_split_sig(info->hdr, &info->len, mangled_module, &sig_len, &sig, "module");
> + if (!err) {
> + err = verify_pkcs7_signature(mod, info->len, sig, sig_len,
> + VERIFY_USE_SECONDARY_KEYRING,
> + VERIFYING_MODULE_SIGNATURE,
> + NULL, NULL);
> if (!err) {
> info->sig_ok = true;
> return 0;
The patch looks to modify the behavior when mangled_module is true.
Previously, module_sig_check() didn't attempt to extract the signature
in such a case and treated the module as unsigned. The err remained set
to -ENODATA and the function subsequently consulted module_sig_check()
and security_locked_down() to determine an appropriate result.
Newly, module_sig_check() calls mod_split_sig(), which skips the
extraction of the marker ("~Module signature appended~\n") from the end
of the module and instead attempts to read it as an actual
module_signature. The value is then passed to mod_check_sig() which
should return -EBADMSG. The error is propagated to module_sig_check()
and treated as fatal, without consulting module_sig_check() and
security_locked_down().
I think the mangled_module flag should not be passed to mod_split_sig()
and it should be handled solely by module_sig_check().
> diff --git a/kernel/module_signature.c b/kernel/module_signature.c
> index 00132d12487c..b2384a73524c 100644
> --- a/kernel/module_signature.c
> +++ b/kernel/module_signature.c
> @@ -8,6 +8,7 @@
>
> #include <linux/errno.h>
> #include <linux/printk.h>
> +#include <linux/string.h>
> #include <linux/module_signature.h>
> #include <asm/byteorder.h>
>
> @@ -18,8 +19,8 @@
> * @file_len: Size of the file to which @ms is appended.
> * @name: What is being checked. Used for error messages.
> */
> -int mod_check_sig(const struct module_signature *ms, size_t file_len,
> - const char *name)
> +static int mod_check_sig(const struct module_signature *ms, size_t file_len,
> + const char *name)
> {
> if (be32_to_cpu(ms->sig_len) >= file_len - sizeof(*ms))
> return -EBADMSG;
> @@ -44,3 +45,39 @@ int mod_check_sig(const struct module_signature *ms, size_t file_len,
>
> return 0;
> }
> +
> +int mod_split_sig(const void *buf, size_t *buf_len, bool mangled,
> + size_t *sig_len, const u8 **sig, const char *name)
> +{
> + const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
> + struct module_signature ms;
> + size_t modlen = *buf_len;
> + int ret;
> +
> + /*
> + * Do not allow mangled modules as a module with version information
> + * removed is no longer the module that was signed.
> + */
> + if (!mangled &&
> + *buf_len > markerlen &&
> + memcmp(buf + modlen - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
> + /* We truncate the module to discard the signature */
> + modlen -= markerlen;
> + }
> +
> + if (modlen <= sizeof(ms))
> + return -EBADMSG;
> +
> + memcpy(&ms, buf + (modlen - sizeof(ms)), sizeof(ms));
> +
> + ret = mod_check_sig(&ms, modlen, name);
> + if (ret)
> + return ret;
> +
> + *sig_len = be32_to_cpu(ms.sig_len);
> + modlen -= *sig_len + sizeof(ms);
> + *buf_len = modlen;
> + *sig = buf + modlen;
> +
> + return 0;
> +}
> diff --git a/security/integrity/ima/ima_modsig.c b/security/integrity/ima/ima_modsig.c
> index 3265d744d5ce..a57342d39b07 100644
> --- a/security/integrity/ima/ima_modsig.c
> +++ b/security/integrity/ima/ima_modsig.c
> @@ -40,44 +40,30 @@ struct modsig {
> int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len,
> struct modsig **modsig)
> {
> - const size_t marker_len = strlen(MODULE_SIG_STRING);
> - const struct module_signature *sig;
> + size_t buf_len_sz = buf_len;
> struct modsig *hdr;
> size_t sig_len;
> - const void *p;
> + const u8 *sig;
> int rc;
>
> - if (buf_len <= marker_len + sizeof(*sig))
> - return -ENOENT;
> -
> - p = buf + buf_len - marker_len;
> - if (memcmp(p, MODULE_SIG_STRING, marker_len))
> - return -ENOENT;
> -
> - buf_len -= marker_len;
> - sig = (const struct module_signature *)(p - sizeof(*sig));
> -
> - rc = mod_check_sig(sig, buf_len, func_tokens[func]);
> + rc = mod_split_sig(buf, &buf_len_sz, true, &sig_len, &sig, func_tokens[func]);
Passing mangled=true to mod_split_sig() seems incorrect here. It causes
that the function doesn't properly extract the signature marker at the
end of the module, no?
> if (rc)
> return rc;
>
> - sig_len = be32_to_cpu(sig->sig_len);
> - buf_len -= sig_len + sizeof(*sig);
> -
> /* Allocate sig_len additional bytes to hold the raw PKCS#7 data. */
> hdr = kzalloc(struct_size(hdr, raw_pkcs7, sig_len), GFP_KERNEL);
> if (!hdr)
> return -ENOMEM;
>
> hdr->raw_pkcs7_len = sig_len;
> - hdr->pkcs7_msg = pkcs7_parse_message(buf + buf_len, sig_len);
> + hdr->pkcs7_msg = pkcs7_parse_message(sig, sig_len);
> if (IS_ERR(hdr->pkcs7_msg)) {
> rc = PTR_ERR(hdr->pkcs7_msg);
> kfree(hdr);
> return rc;
> }
>
> - memcpy(hdr->raw_pkcs7, buf + buf_len, sig_len);
> + memcpy(hdr->raw_pkcs7, sig, sig_len);
>
> /* We don't know the hash algorithm yet. */
> hdr->hash_algo = HASH_ALGO__LAST;
>
--
Thanks,
Petr
^ permalink raw reply
* [PATCH v4] ima_fs: Avoid creating measurement lists for unsupported hash algos
From: Dmitry Safonov via B4 Relay @ 2026-01-27 15:03 UTC (permalink / raw)
To: Mimi Zohar, Roberto Sassu, Dmitry Kasatkin, Eric Snowberg,
Paul Moore, James Morris, Serge E. Hallyn, Silvia Sisinni,
Enrico Bravi
Cc: linux-integrity, linux-security-module, linux-kernel, stable,
Dmitry Safonov, Dmitry Safonov
From: Dmitry Safonov <dima@arista.com>
ima_init_crypto() skips initializing ima_algo_array[i] if the algorithm
from ima_tpm_chip->allocated_banks[i].crypto_id is not supported.
It seems avoid adding the unsupported algorithm to ima_algo_array will
break all the logic that relies on indexing by NR_BANKS(ima_tpm_chip).
On 6.12.40 I observe the following read out-of-bounds in hash_algo_name:
> ==================================================================
> BUG: KASAN: global-out-of-bounds in create_securityfs_measurement_lists+0x396/0x440
> Read of size 8 at addr ffffffff83e18138 by task swapper/0/1
>
> CPU: 4 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.40 #3
> Call Trace:
> <TASK>
> dump_stack_lvl+0x61/0x90
> print_report+0xc4/0x580
> ? kasan_addr_to_slab+0x26/0x80
> ? create_securityfs_measurement_lists+0x396/0x440
> kasan_report+0xc2/0x100
> ? create_securityfs_measurement_lists+0x396/0x440
> create_securityfs_measurement_lists+0x396/0x440
> ima_fs_init+0xa3/0x300
> ima_init+0x7d/0xd0
> init_ima+0x28/0x100
> do_one_initcall+0xa6/0x3e0
> kernel_init_freeable+0x455/0x740
> kernel_init+0x24/0x1d0
> ret_from_fork+0x38/0x80
> ret_from_fork_asm+0x11/0x20
> </TASK>
>
> The buggy address belongs to the variable:
> hash_algo_name+0xb8/0x420
>
> The buggy address belongs to the physical page:
> page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x107ce18
> flags: 0x8000000000002000(reserved|zone=2)
> raw: 8000000000002000 ffffea0041f38608 ffffea0041f38608 0000000000000000
> raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
> page dumped because: kasan: bad access detected
>
> Memory state around the buggy address:
> ffffffff83e18000: 00 01 f9 f9 f9 f9 f9 f9 00 01 f9 f9 f9 f9 f9 f9
> ffffffff83e18080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> >ffffffff83e18100: 00 00 00 00 00 00 00 f9 f9 f9 f9 f9 00 05 f9 f9
> ^
> ffffffff83e18180: f9 f9 f9 f9 00 00 00 00 00 00 00 04 f9 f9 f9 f9
> ffffffff83e18200: 00 00 00 00 00 00 00 00 04 f9 f9 f9 f9 f9 f9 f9
> ==================================================================
Seems like the TPM chip supports sha3_256, which isn't yet in
tpm_algorithms:
> tpm tpm0: TPM with unsupported bank algorithm 0x0027
Use TPM_ALG_<ID> as a postfix for file names for unsupported hashing algorithms.
This is how it looks on the test machine I have:
> # ls -1 /sys/kernel/security/ima/
> ascii_runtime_measurements
> ascii_runtime_measurements_TPM_ALG_27
> ascii_runtime_measurements_sha1
> ascii_runtime_measurements_sha256
> binary_runtime_measurements
> binary_runtime_measurements_TPM_ALG_27
> binary_runtime_measurements_sha1
> binary_runtime_measurements_sha256
> policy
> runtime_measurements_count
> violations
Fixes: 9fa8e7625008 ("ima: add crypto agility support for template-hash algorithm")
Signed-off-by: Dmitry Safonov <dima@arista.com>
Cc: Enrico Bravi <enrico.bravi@polito.it>
Cc: Silvia Sisinni <silvia.sisinni@polito.it>
Cc: Roberto Sassu <roberto.sassu@huawei.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>
---
Changes in v4:
- Use ima_tpm_chip->allocated_banks[algo_idx].digest_size instead of hash_digest_size[algo]
(Roberto Sassu)
- Link to v3: https://lore.kernel.org/r/20260127-ima-oob-v3-1-1dd09f4c2a6a@arista.com
Testing note: I test it on v6.12.40 kernel backport, which slightly differs as
lookup_template_data_hash_algo() was yet present.
Changes in v3:
- Now fix the spelling *for real* (sorry, messed it up in v2)
- Link to v2: https://lore.kernel.org/r/20260127-ima-oob-v2-1-f38a18c850cf@arista.com
Changes in v2:
- Instead of skipping unknown algorithms, add files under their TPM_ALG_ID (Roberto Sassu)
- Fix spelling (Roberto Sassu)
- Copy @stable on the fix
- Link to v1: https://lore.kernel.org/r/20260127-ima-oob-v1-1-2d42f3418e57@arista.com
---
security/integrity/ima/ima_fs.c | 34 ++++++++++++++++++----------------
1 file changed, 18 insertions(+), 16 deletions(-)
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index 012a58959ff0..9a00a0547619 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -132,16 +132,12 @@ int ima_measurements_show(struct seq_file *m, void *v)
char *template_name;
u32 pcr, namelen, template_data_len; /* temporary fields */
bool is_ima_template = false;
- enum hash_algo algo;
int i, algo_idx;
algo_idx = ima_sha1_idx;
- algo = HASH_ALGO_SHA1;
- if (m->file != NULL) {
+ if (m->file != NULL)
algo_idx = (unsigned long)file_inode(m->file)->i_private;
- algo = ima_algo_array[algo_idx].algo;
- }
/* get entry */
e = qe->entry;
@@ -160,7 +156,8 @@ int ima_measurements_show(struct seq_file *m, void *v)
ima_putc(m, &pcr, sizeof(e->pcr));
/* 2nd: template digest */
- ima_putc(m, e->digests[algo_idx].digest, hash_digest_size[algo]);
+ ima_putc(m, e->digests[algo_idx].digest,
+ ima_tpm_chip->allocated_banks[algo_idx].digest_size);
/* 3rd: template name size */
namelen = !ima_canonical_fmt ? strlen(template_name) :
@@ -229,16 +226,12 @@ static int ima_ascii_measurements_show(struct seq_file *m, void *v)
struct ima_queue_entry *qe = v;
struct ima_template_entry *e;
char *template_name;
- enum hash_algo algo;
int i, algo_idx;
algo_idx = ima_sha1_idx;
- algo = HASH_ALGO_SHA1;
- if (m->file != NULL) {
+ if (m->file != NULL)
algo_idx = (unsigned long)file_inode(m->file)->i_private;
- algo = ima_algo_array[algo_idx].algo;
- }
/* get entry */
e = qe->entry;
@@ -252,7 +245,8 @@ static int ima_ascii_measurements_show(struct seq_file *m, void *v)
seq_printf(m, "%2d ", e->pcr);
/* 2nd: template hash */
- ima_print_digest(m, e->digests[algo_idx].digest, hash_digest_size[algo]);
+ ima_print_digest(m, e->digests[algo_idx].digest,
+ ima_tpm_chip->allocated_banks[algo_idx].digest_size);
/* 3th: template name */
seq_printf(m, " %s", template_name);
@@ -404,16 +398,24 @@ static int __init create_securityfs_measurement_lists(void)
char file_name[NAME_MAX + 1];
struct dentry *dentry;
- sprintf(file_name, "ascii_runtime_measurements_%s",
- hash_algo_name[algo]);
+ if (algo == HASH_ALGO__LAST)
+ sprintf(file_name, "ascii_runtime_measurements_TPM_ALG_%x",
+ ima_tpm_chip->allocated_banks[i].alg_id);
+ else
+ sprintf(file_name, "ascii_runtime_measurements_%s",
+ hash_algo_name[algo]);
dentry = securityfs_create_file(file_name, S_IRUSR | S_IRGRP,
ima_dir, (void *)(uintptr_t)i,
&ima_ascii_measurements_ops);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
- sprintf(file_name, "binary_runtime_measurements_%s",
- hash_algo_name[algo]);
+ if (algo == HASH_ALGO__LAST)
+ sprintf(file_name, "binary_runtime_measurements_TPM_ALG_%x",
+ ima_tpm_chip->allocated_banks[i].alg_id);
+ else
+ sprintf(file_name, "binary_runtime_measurements_%s",
+ hash_algo_name[algo]);
dentry = securityfs_create_file(file_name, S_IRUSR | S_IRGRP,
ima_dir, (void *)(uintptr_t)i,
&ima_measurements_ops);
---
base-commit: 63804fed149a6750ffd28610c5c1c98cce6bd377
change-id: 20260127-ima-oob-9fa83a634d7b
Best regards,
--
Dmitry Safonov <dima@arista.com>
^ permalink raw reply related
* [PATCH v5 4/6] pseries/plpks: add HCALLs for PowerVM Key Wrapping Module
From: Srish Srinivasan @ 2026-01-27 14:52 UTC (permalink / raw)
To: linux-integrity, keyrings, linuxppc-dev
Cc: maddy, mpe, npiggin, christophe.leroy, James.Bottomley, jarkko,
zohar, nayna, rnsastry, linux-kernel, linux-security-module,
ssrish
In-Reply-To: <20260127145228.48320-1-ssrish@linux.ibm.com>
The hypervisor generated wrapping key is an AES-GCM-256 symmetric key which
is stored in a non-volatile, secure, and encrypted storage called the Power
LPAR Platform KeyStore. It has policy based protections that prevent it
from being read out or exposed to the user.
Implement H_PKS_GEN_KEY, H_PKS_WRAP_OBJECT, and H_PKS_UNWRAP_OBJECT HCALLs
to enable using the PowerVM Key Wrapping Module (PKWM) as a new trust
source for trusted keys. Disallow H_PKS_READ_OBJECT, H_PKS_SIGNED_UPDATE,
and H_PKS_WRITE_OBJECT for objects with the 'wrapping key' policy set.
Capture the availability status for the H_PKS_WRAP_OBJECT interface.
Signed-off-by: Srish Srinivasan <ssrish@linux.ibm.com>
Reviewed-by: Nayna Jain <nayna@linux.ibm.com>
---
Documentation/arch/powerpc/papr_hcalls.rst | 43 +++
arch/powerpc/include/asm/plpks.h | 10 +
arch/powerpc/platforms/pseries/plpks.c | 343 ++++++++++++++++++++-
3 files changed, 394 insertions(+), 2 deletions(-)
diff --git a/Documentation/arch/powerpc/papr_hcalls.rst b/Documentation/arch/powerpc/papr_hcalls.rst
index 805e1cb9bab9..14e39f095a1c 100644
--- a/Documentation/arch/powerpc/papr_hcalls.rst
+++ b/Documentation/arch/powerpc/papr_hcalls.rst
@@ -300,6 +300,49 @@ H_HTM supports setup, configuration, control and dumping of Hardware Trace
Macro (HTM) function and its data. HTM buffer stores tracing data for functions
like core instruction, core LLAT and nest.
+**H_PKS_GEN_KEY**
+
+| Input: authorization, objectlabel, objectlabellen, policy, out, outlen
+| Out: *Hypervisor Generated Key, or None when the wrapping key policy is set*
+| Return Value: *H_SUCCESS, H_Function, H_State, H_R_State, H_Parameter, H_P2,
+ H_P3, H_P4, H_P5, H_P6, H_Authority, H_Nomem, H_Busy, H_Resource,
+ H_Aborted*
+
+H_PKS_GEN_KEY is used to have the hypervisor generate a new random key.
+This key is stored as an object in the Power LPAR Platform KeyStore with
+the provided object label. With the wrapping key policy set the key is only
+visible to the hypervisor, while the key's label would still be visible to
+the user. Generation of wrapping keys is supported only for a key size of
+32 bytes.
+
+**H_PKS_WRAP_OBJECT**
+
+| Input: authorization, wrapkeylabel, wrapkeylabellen, objectwrapflags, in,
+| inlen, out, outlen, continue-token
+| Out: *continue-token, byte size of wrapped object, wrapped object*
+| Return Value: *H_SUCCESS, H_Function, H_State, H_R_State, H_Parameter, H_P2,
+ H_P3, H_P4, H_P5, H_P6, H_P7, H_P8, H_P9, H_Authority, H_Invalid_Key,
+ H_NOT_FOUND, H_Busy, H_LongBusy, H_Aborted*
+
+H_PKS_WRAP_OBJECT is used to wrap an object using a wrapping key stored in the
+Power LPAR Platform KeyStore and return the wrapped object to the caller. The
+caller provides a label to a wrapping key with the 'wrapping key' policy set,
+which must have been previously created with H_PKS_GEN_KEY. The provided object
+is then encrypted with the wrapping key and additional metadata and the result
+is returned to the caller.
+
+
+**H_PKS_UNWRAP_OBJECT**
+
+| Input: authorization, objectwrapflags, in, inlen, out, outlen, continue-token
+| Out: *continue-token, byte size of unwrapped object, unwrapped object*
+| Return Value: *H_SUCCESS, H_Function, H_State, H_R_State, H_Parameter, H_P2,
+ H_P3, H_P4, H_P5, H_P6, H_P7, H_Authority, H_Unsupported, H_Bad_Data,
+ H_NOT_FOUND, H_Invalid_Key, H_Busy, H_LongBusy, H_Aborted*
+
+H_PKS_UNWRAP_OBJECT is used to unwrap an object that was previously warapped with
+H_PKS_WRAP_OBJECT.
+
References
==========
.. [1] "Power Architecture Platform Reference"
diff --git a/arch/powerpc/include/asm/plpks.h b/arch/powerpc/include/asm/plpks.h
index 8f034588fdf7..e87f90e40d4e 100644
--- a/arch/powerpc/include/asm/plpks.h
+++ b/arch/powerpc/include/asm/plpks.h
@@ -113,6 +113,16 @@ void plpks_early_init_devtree(void);
int plpks_populate_fdt(void *fdt);
int plpks_config_create_softlink(struct kobject *from);
+
+bool plpks_wrapping_is_supported(void);
+
+int plpks_gen_wrapping_key(void);
+
+int plpks_wrap_object(u8 **input_buf, u32 input_len, u16 wrap_flags,
+ u8 **output_buf, u32 *output_len);
+
+int plpks_unwrap_object(u8 **input_buf, u32 input_len,
+ u8 **output_buf, u32 *output_len);
#else // CONFIG_PSERIES_PLPKS
static inline bool plpks_is_available(void) { return false; }
static inline u16 plpks_get_passwordlen(void) { BUILD_BUG(); }
diff --git a/arch/powerpc/platforms/pseries/plpks.c b/arch/powerpc/platforms/pseries/plpks.c
index 4a08f51537c8..038ecf8f6d6b 100644
--- a/arch/powerpc/platforms/pseries/plpks.c
+++ b/arch/powerpc/platforms/pseries/plpks.c
@@ -9,6 +9,32 @@
#define pr_fmt(fmt) "plpks: " fmt
+#define PLPKS_WRAPKEY_COMPONENT "PLPKSWR"
+#define PLPKS_WRAPKEY_NAME "default-wrapping-key"
+
+/*
+ * To 4K align the {input, output} buffers to the {UN}WRAP H_CALLs
+ */
+#define PLPKS_WRAPPING_BUF_ALIGN 4096
+
+/*
+ * To ensure the output buffer's length is at least 1024 bytes greater
+ * than the input buffer's length during the WRAP H_CALL
+ */
+#define PLPKS_WRAPPING_BUF_DIFF 1024
+
+#define PLPKS_WRAP_INTERFACE_BIT 3
+#define PLPKS_WRAPPING_KEY_LENGTH 32
+
+#define WRAPFLAG_BE_BIT_SET(be_bit) \
+ BIT_ULL(63 - (be_bit))
+
+#define WRAPFLAG_BE_GENMASK(be_bit_hi, be_bit_lo) \
+ GENMASK_ULL(63 - (be_bit_hi), 63 - (be_bit_lo))
+
+#define WRAPFLAG_BE_FIELD_PREP(be_bit_hi, be_bit_lo, val) \
+ FIELD_PREP(WRAPFLAG_BE_GENMASK(be_bit_hi, be_bit_lo), (val))
+
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/io.h>
@@ -19,6 +45,7 @@
#include <linux/of_fdt.h>
#include <linux/libfdt.h>
#include <linux/memblock.h>
+#include <linux/bitfield.h>
#include <asm/hvcall.h>
#include <asm/machdep.h>
#include <asm/plpks.h>
@@ -39,6 +66,7 @@ static u32 supportedpolicies;
static u32 maxlargeobjectsize;
static u64 signedupdatealgorithms;
static u64 wrappingfeatures;
+static bool wrapsupport;
struct plpks_auth {
u8 version;
@@ -283,6 +311,7 @@ static int _plpks_get_config(void)
maxlargeobjectsize = be32_to_cpu(config->maxlargeobjectsize);
signedupdatealgorithms = be64_to_cpu(config->signedupdatealgorithms);
wrappingfeatures = be64_to_cpu(config->wrappingfeatures);
+ wrapsupport = config->flags & PPC_BIT8(PLPKS_WRAP_INTERFACE_BIT);
// Validate that the numbers we get back match the requirements of the spec
if (maxpwsize < 32) {
@@ -614,6 +643,9 @@ int plpks_signed_update_var(struct plpks_var *var, u64 flags)
if (!(var->policy & PLPKS_SIGNEDUPDATE))
return -EINVAL;
+ if (var->policy & PLPKS_WRAPPINGKEY)
+ return -EINVAL;
+
// Signed updates need the component to be NULL.
if (var->component)
return -EINVAL;
@@ -696,6 +728,9 @@ int plpks_write_var(struct plpks_var var)
if (var.policy & PLPKS_SIGNEDUPDATE)
return -EINVAL;
+ if (var.policy & PLPKS_WRAPPINGKEY)
+ return -EINVAL;
+
auth = construct_auth(PLPKS_OS_OWNER);
if (IS_ERR(auth))
return PTR_ERR(auth);
@@ -790,6 +825,9 @@ static int plpks_read_var(u8 consumer, struct plpks_var *var)
if (var->namelen > PLPKS_MAX_NAME_SIZE)
return -EINVAL;
+ if (var->policy & PLPKS_WRAPPINGKEY)
+ return -EINVAL;
+
auth = construct_auth(consumer);
if (IS_ERR(auth))
return PTR_ERR(auth);
@@ -845,8 +883,309 @@ static int plpks_read_var(u8 consumer, struct plpks_var *var)
}
/**
- * plpks_read_os_var() - Fetch the data for the specified variable that is
- * owned by the OS consumer.
+ * plpks_wrapping_is_supported() - Get the H_PKS_WRAP_OBJECT interface
+ * availability status for the LPAR.
+ *
+ * Successful execution of the H_PKS_GET_CONFIG HCALL during initialization
+ * sets bit 3 of the flags variable in the PLPKS config structure if the
+ * H_PKS_WRAP_OBJECT interface is supported.
+ *
+ * Returns: true if the H_PKS_WRAP_OBJECT interface is supported, false if not.
+ */
+bool plpks_wrapping_is_supported(void)
+{
+ return wrapsupport;
+}
+
+/**
+ * plpks_gen_wrapping_key() - Generate a new random key with the 'wrapping key'
+ * policy set.
+ *
+ * The H_PKS_GEN_KEY HCALL makes the hypervisor generate a new random key and
+ * store the key in a PLPKS object with the provided object label. With the
+ * 'wrapping key' policy set, only the label to the newly generated random key
+ * would be visible to the user.
+ *
+ * Possible reasons for the returned errno values:
+ *
+ * -ENXIO if PLPKS is not supported
+ * -EIO if PLPKS access is blocked due to the LPAR's state
+ * if PLPKS modification is blocked due to the LPAR's state
+ * if an error occurred while processing the request
+ * -EINVAL if invalid authorization parameter
+ * if invalid object label parameter
+ * if invalid object label len parameter
+ * if invalid or unsupported policy declaration
+ * if invalid output buffer parameter
+ * if invalid output buffer length parameter
+ * -EPERM if access is denied
+ * -ENOMEM if there is inadequate memory to perform this operation
+ * -EBUSY if unable to handle the request
+ * -EEXIST if the object label already exists
+ *
+ * Returns: On success 0 is returned, a negative errno if not.
+ */
+int plpks_gen_wrapping_key(void)
+{
+ unsigned long retbuf[PLPAR_HCALL_BUFSIZE] = { 0 };
+ struct plpks_auth *auth;
+ struct label *label;
+ int rc = 0, pseries_status = 0;
+ struct plpks_var var = {
+ .name = PLPKS_WRAPKEY_NAME,
+ .namelen = strlen(var.name),
+ .policy = PLPKS_WRAPPINGKEY,
+ .os = PLPKS_VAR_LINUX,
+ .component = PLPKS_WRAPKEY_COMPONENT
+ };
+
+ auth = construct_auth(PLPKS_OS_OWNER);
+ if (IS_ERR(auth))
+ return PTR_ERR(auth);
+
+ label = construct_label(var.component, var.os, var.name, var.namelen);
+ if (IS_ERR(label)) {
+ rc = PTR_ERR(label);
+ goto out;
+ }
+
+ rc = plpar_hcall(H_PKS_GEN_KEY, retbuf,
+ virt_to_phys(auth), virt_to_phys(label),
+ label->size, var.policy,
+ NULL, PLPKS_WRAPPING_KEY_LENGTH);
+
+ if (!rc)
+ rc = plpks_confirm_object_flushed(label, auth);
+
+ pseries_status = rc;
+ rc = pseries_status_to_err(rc);
+
+ if (rc && rc != -EEXIST) {
+ pr_err("H_PKS_GEN_KEY failed. pseries_status=%d, rc=%d",
+ pseries_status, rc);
+ } else {
+ rc = 0;
+ }
+
+ kfree(label);
+out:
+ kfree(auth);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(plpks_gen_wrapping_key);
+
+/**
+ * plpks_wrap_object() - Wrap an object using the default wrapping key stored in
+ * the PLPKS.
+ * @input_buf: buffer containing the data to be wrapped
+ * @input_len: length of the input buffer
+ * @wrap_flags: object wrapping flags
+ * @output_buf: buffer to store the wrapped data
+ * @output_len: length of the output buffer
+ *
+ * The H_PKS_WRAP_OBJECT HCALL wraps an object using a wrapping key stored in
+ * the PLPKS and returns the wrapped object to the caller. The caller provides a
+ * label to the wrapping key with the 'wrapping key' policy set that must have
+ * been previously created with the H_PKS_GEN_KEY HCALL. The provided object is
+ * then encrypted with the wrapping key and additional metadata and the result
+ * is returned to the user. The metadata includes the wrapping algorithm and the
+ * wrapping key name so those parameters are not required during unwrap.
+ *
+ * Possible reasons for the returned errno values:
+ *
+ * -ENXIO if PLPKS is not supported
+ * -EIO if PLPKS access is blocked due to the LPAR's state
+ * if PLPKS modification is blocked due to the LPAR's state
+ * if an error occurred while processing the request
+ * -EINVAL if invalid authorization parameter
+ * if invalid wrapping key label parameter
+ * if invalid wrapping key label length parameter
+ * if invalid or unsupported object wrapping flags
+ * if invalid input buffer parameter
+ * if invalid input buffer length parameter
+ * if invalid output buffer parameter
+ * if invalid output buffer length parameter
+ * if invalid continue token parameter
+ * if the wrapping key is not compatible with the wrapping
+ * algorithm
+ * -EPERM if access is denied
+ * -ENOENT if the requested wrapping key was not found
+ * -EBUSY if unable to handle the request or long running operation
+ * initiated, retry later.
+ *
+ * Returns: On success 0 is returned, a negative errno if not.
+ */
+int plpks_wrap_object(u8 **input_buf, u32 input_len, u16 wrap_flags,
+ u8 **output_buf, u32 *output_len)
+{
+ unsigned long retbuf[PLPAR_HCALL9_BUFSIZE] = { 0 };
+ struct plpks_auth *auth;
+ struct label *label;
+ u64 continuetoken = 0;
+ u64 objwrapflags = 0;
+ int rc = 0, pseries_status = 0;
+ bool sb_audit_or_enforce_bit = wrap_flags & BIT(0);
+ bool sb_enforce_bit = wrap_flags & BIT(1);
+ struct plpks_var var = {
+ .name = PLPKS_WRAPKEY_NAME,
+ .namelen = strlen(var.name),
+ .os = PLPKS_VAR_LINUX,
+ .component = PLPKS_WRAPKEY_COMPONENT
+ };
+
+ auth = construct_auth(PLPKS_OS_OWNER);
+ if (IS_ERR(auth))
+ return PTR_ERR(auth);
+
+ label = construct_label(var.component, var.os, var.name, var.namelen);
+ if (IS_ERR(label)) {
+ rc = PTR_ERR(label);
+ goto out;
+ }
+
+ /* Set the consumer password requirement bit. A must have. */
+ objwrapflags |= WRAPFLAG_BE_BIT_SET(3);
+
+ /* Set the wrapping algorithm bit. Just one algorithm option for now */
+ objwrapflags |= WRAPFLAG_BE_FIELD_PREP(60, 63, 0x1);
+
+ if (sb_audit_or_enforce_bit & sb_enforce_bit) {
+ pr_err("Cannot set both audit/enforce and enforce bits.");
+ rc = -EINVAL;
+ goto out_free_label;
+ } else if (sb_audit_or_enforce_bit) {
+ objwrapflags |= WRAPFLAG_BE_BIT_SET(1);
+ } else if (sb_enforce_bit) {
+ objwrapflags |= WRAPFLAG_BE_BIT_SET(2);
+ }
+
+ *output_len = input_len + PLPKS_WRAPPING_BUF_DIFF;
+
+ *output_buf = kzalloc(ALIGN(*output_len, PLPKS_WRAPPING_BUF_ALIGN),
+ GFP_KERNEL);
+ if (!(*output_buf)) {
+ pr_err("Output buffer allocation failed. Returning -ENOMEM.");
+ rc = -ENOMEM;
+ goto out_free_label;
+ }
+
+ do {
+ rc = plpar_hcall9(H_PKS_WRAP_OBJECT, retbuf,
+ virt_to_phys(auth), virt_to_phys(label),
+ label->size, objwrapflags,
+ virt_to_phys(*input_buf), input_len,
+ virt_to_phys(*output_buf), *output_len,
+ continuetoken);
+
+ continuetoken = retbuf[0];
+ pseries_status = rc;
+ rc = pseries_status_to_err(rc);
+ } while (rc == -EBUSY);
+
+ if (rc) {
+ pr_err("H_PKS_WRAP_OBJECT failed. pseries_status=%d, rc=%d",
+ pseries_status, rc);
+ kfree(*output_buf);
+ *output_buf = NULL;
+ } else {
+ *output_len = retbuf[1];
+ }
+
+out_free_label:
+ kfree(label);
+out:
+ kfree(auth);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(plpks_wrap_object);
+
+/**
+ * plpks_unwrap_object() - Unwrap an object using the default wrapping key
+ * stored in the PLPKS.
+ * @input_buf: buffer containing the data to be unwrapped
+ * @input_len: length of the input buffer
+ * @output_buf: buffer to store the unwrapped data
+ * @output_len: length of the output buffer
+ *
+ * The H_PKS_UNWRAP_OBJECT HCALL unwraps an object that was previously wrapped
+ * using the H_PKS_WRAP_OBJECT HCALL.
+ *
+ * Possible reasons for the returned errno values:
+ *
+ * -ENXIO if PLPKS is not supported
+ * -EIO if PLPKS access is blocked due to the LPAR's state
+ * if PLPKS modification is blocked due to the LPAR's state
+ * if an error occurred while processing the request
+ * -EINVAL if invalid authorization parameter
+ * if invalid or unsupported object unwrapping flags
+ * if invalid input buffer parameter
+ * if invalid input buffer length parameter
+ * if invalid output buffer parameter
+ * if invalid output buffer length parameter
+ * if invalid continue token parameter
+ * if the wrapping key is not compatible with the wrapping
+ * algorithm
+ * if the wrapped object's format is not supported
+ * if the wrapped object is invalid
+ * -EPERM if access is denied
+ * -ENOENT if the wrapping key for the provided object was not found
+ * -EBUSY if unable to handle the request or long running operation
+ * initiated, retry later.
+ *
+ * Returns: On success 0 is returned, a negative errno if not.
+ */
+int plpks_unwrap_object(u8 **input_buf, u32 input_len, u8 **output_buf,
+ u32 *output_len)
+{
+ unsigned long retbuf[PLPAR_HCALL9_BUFSIZE] = { 0 };
+ struct plpks_auth *auth;
+ u64 continuetoken = 0;
+ u64 objwrapflags = 0;
+ int rc = 0, pseries_status = 0;
+
+ auth = construct_auth(PLPKS_OS_OWNER);
+ if (IS_ERR(auth))
+ return PTR_ERR(auth);
+
+ *output_len = input_len - PLPKS_WRAPPING_BUF_DIFF;
+ *output_buf = kzalloc(ALIGN(*output_len, PLPKS_WRAPPING_BUF_ALIGN),
+ GFP_KERNEL);
+ if (!(*output_buf)) {
+ pr_err("Output buffer allocation failed. Returning -ENOMEM.");
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ do {
+ rc = plpar_hcall9(H_PKS_UNWRAP_OBJECT, retbuf,
+ virt_to_phys(auth), objwrapflags,
+ virt_to_phys(*input_buf), input_len,
+ virt_to_phys(*output_buf), *output_len,
+ continuetoken);
+
+ continuetoken = retbuf[0];
+ pseries_status = rc;
+ rc = pseries_status_to_err(rc);
+ } while (rc == -EBUSY);
+
+ if (rc) {
+ pr_err("H_PKS_UNWRAP_OBJECT failed. pseries_status=%d, rc=%d",
+ pseries_status, rc);
+ kfree(*output_buf);
+ *output_buf = NULL;
+ } else {
+ *output_len = retbuf[1];
+ }
+
+out:
+ kfree(auth);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(plpks_unwrap_object);
+
+/**
+ * plpks_read_os_var() - Fetch the data for the specified variable that is owned
+ * by the OS consumer.
* @var: variable to be read from the PLPKS
*
* The consumer or the owner of the object is the os kernel. The
--
2.47.3
^ permalink raw reply related
* [PATCH v5 6/6] docs: trusted-encryped: add PKWM as a new trust source
From: Srish Srinivasan @ 2026-01-27 14:52 UTC (permalink / raw)
To: linux-integrity, keyrings, linuxppc-dev
Cc: maddy, mpe, npiggin, christophe.leroy, James.Bottomley, jarkko,
zohar, nayna, rnsastry, linux-kernel, linux-security-module,
ssrish
In-Reply-To: <20260127145228.48320-1-ssrish@linux.ibm.com>
From: Nayna Jain <nayna@linux.ibm.com>
Update Documentation/security/keys/trusted-encrypted.rst and Documentation/
admin-guide/kernel-parameters.txt with PowerVM Key Wrapping Module (PKWM)
as a new trust source
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Srish Srinivasan <ssrish@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
---
.../admin-guide/kernel-parameters.txt | 1 +
.../security/keys/trusted-encrypted.rst | 50 +++++++++++++++++++
2 files changed, 51 insertions(+)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 1058f2a6d6a8..aac15079b33d 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -7790,6 +7790,7 @@ Kernel parameters
- "tee"
- "caam"
- "dcp"
+ - "pkwm"
If not specified then it defaults to iterating through
the trust source list starting with TPM and assigns the
first trust source as a backend which is initialized
diff --git a/Documentation/security/keys/trusted-encrypted.rst b/Documentation/security/keys/trusted-encrypted.rst
index eae6a36b1c9a..ddff7c7c2582 100644
--- a/Documentation/security/keys/trusted-encrypted.rst
+++ b/Documentation/security/keys/trusted-encrypted.rst
@@ -81,6 +81,14 @@ safe.
and the UNIQUE key. Default is to use the UNIQUE key, but selecting
the OTP key can be done via a module parameter (dcp_use_otp_key).
+ (5) PKWM (PowerVM Key Wrapping Module: IBM PowerVM + Platform KeyStore)
+
+ Rooted to a unique, per-LPAR key, which is derived from a system-wide,
+ randomly generated LPAR root key. Both the per-LPAR keys and the LPAR
+ root key are stored in hypervisor-owned secure memory at runtime,
+ and the LPAR root key is additionally persisted in secure locations
+ such as the processor SEEPROMs and encrypted NVRAM.
+
* Execution isolation
(1) TPM
@@ -102,6 +110,14 @@ safe.
environment. Only basic blob key encryption is executed there.
The actual key sealing/unsealing is done on main processor/kernel space.
+ (5) PKWM (PowerVM Key Wrapping Module: IBM PowerVM + Platform KeyStore)
+
+ Fixed set of cryptographic operations done on on-chip hardware
+ cryptographic acceleration unit NX. Keys for wrapping and unwrapping
+ are managed by PowerVM Platform KeyStore, which stores keys in an
+ isolated in-memory copy in secure hypervisor memory, as well as in a
+ persistent copy in hypervisor-encrypted NVRAM.
+
* Optional binding to platform integrity state
(1) TPM
@@ -129,6 +145,11 @@ safe.
Relies on Secure/Trusted boot process (called HAB by vendor) for
platform integrity.
+ (5) PKWM (PowerVM Key Wrapping Module: IBM PowerVM + Platform KeyStore)
+
+ Relies on secure and trusted boot process of IBM Power systems for
+ platform integrity.
+
* Interfaces and APIs
(1) TPM
@@ -149,6 +170,11 @@ safe.
Vendor-specific API that is implemented as part of the DCP crypto driver in
``drivers/crypto/mxs-dcp.c``.
+ (5) PKWM (PowerVM Key Wrapping Module: IBM PowerVM + Platform KeyStore)
+
+ Platform Keystore has well documented interfaces in PAPR document.
+ Refer to ``Documentation/arch/powerpc/papr_hcalls.rst``
+
* Threat model
The strength and appropriateness of a particular trust source for a given
@@ -191,6 +217,10 @@ selected trust source:
a dedicated hardware RNG that is independent from DCP which can be enabled
to back the kernel RNG.
+ * PKWM (PowerVM Key Wrapping Module: IBM PowerVM + Platform KeyStore)
+
+ The normal kernel random number generator is used to generate keys.
+
Users may override this by specifying ``trusted.rng=kernel`` on the kernel
command-line to override the used RNG with the kernel's random number pool.
@@ -321,6 +351,26 @@ Usage::
specific to this DCP key-blob implementation. The key length for new keys is
always in bytes. Trusted Keys can be 32 - 128 bytes (256 - 1024 bits).
+Trusted Keys usage: PKWM
+------------------------
+
+Usage::
+
+ keyctl add trusted name "new keylen [options]" ring
+ keyctl add trusted name "load hex_blob" ring
+ keyctl print keyid
+
+ options:
+ wrap_flags= ascii hex value of security policy requirement
+ 0x00: no secure boot requirement (default)
+ 0x01: require secure boot to be in either audit or
+ enforced mode
+ 0x02: require secure boot to be in enforced mode
+
+"keyctl print" returns an ASCII hex copy of the sealed key, which is in format
+specific to PKWM key-blob implementation. The key length for new keys is
+always in bytes. Trusted Keys can be 32 - 128 bytes (256 - 1024 bits).
+
Encrypted Keys usage
--------------------
--
2.47.3
^ permalink raw reply related
* [PATCH v5 5/6] keys/trusted_keys: establish PKWM as a trusted source
From: Srish Srinivasan @ 2026-01-27 14:52 UTC (permalink / raw)
To: linux-integrity, keyrings, linuxppc-dev
Cc: maddy, mpe, npiggin, christophe.leroy, James.Bottomley, jarkko,
zohar, nayna, rnsastry, linux-kernel, linux-security-module,
ssrish
In-Reply-To: <20260127145228.48320-1-ssrish@linux.ibm.com>
The wrapping key does not exist by default and is generated by the
hypervisor as a part of PKWM initialization. This key is then persisted by
the hypervisor and is used to wrap trusted keys. These are variable length
symmetric keys, which in the case of PowerVM Key Wrapping Module (PKWM) are
generated using the kernel RNG. PKWM can be used as a trust source through
the following example keyctl commands:
keyctl add trusted my_trusted_key "new 32" @u
Use the wrap_flags command option to set the secure boot requirement for
the wrapping request through the following keyctl commands
case1: no secure boot requirement. (default)
keyctl usage: keyctl add trusted my_trusted_key "new 32" @u
OR
keyctl add trusted my_trusted_key "new 32 wrap_flags=0x00" @u
case2: secure boot required to in either audit or enforce mode. set bit 0
keyctl usage: keyctl add trusted my_trusted_key "new 32 wrap_flags=0x01" @u
case3: secure boot required to be in enforce mode. set bit 1
keyctl usage: keyctl add trusted my_trusted_key "new 32 wrap_flags=0x02" @u
NOTE:
-> Setting the secure boot requirement is NOT a must.
-> Only either of the secure boot requirement options should be set. Not
both.
-> All the other bits are required to be not set.
-> Set the kernel parameter trusted.source=pkwm to choose PKWM as the
backend for trusted keys implementation.
-> CONFIG_PSERIES_PLPKS must be enabled to build PKWM.
Add PKWM, which is a combination of IBM PowerVM and Power LPAR Platform
KeyStore, as a new trust source for trusted keys.
Signed-off-by: Srish Srinivasan <ssrish@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Nayna Jain <nayna@linux.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
---
MAINTAINERS | 9 +
include/keys/trusted-type.h | 7 +-
include/keys/trusted_pkwm.h | 33 ++++
security/keys/trusted-keys/Kconfig | 8 +
security/keys/trusted-keys/Makefile | 2 +
security/keys/trusted-keys/trusted_core.c | 6 +-
security/keys/trusted-keys/trusted_pkwm.c | 190 ++++++++++++++++++++++
7 files changed, 253 insertions(+), 2 deletions(-)
create mode 100644 include/keys/trusted_pkwm.h
create mode 100644 security/keys/trusted-keys/trusted_pkwm.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 67db88b04537..7ffa45b903d6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14014,6 +14014,15 @@ S: Supported
F: include/keys/trusted_dcp.h
F: security/keys/trusted-keys/trusted_dcp.c
+KEYS-TRUSTED-PLPKS
+M: Srish Srinivasan <ssrish@linux.ibm.com>
+M: Nayna Jain <nayna@linux.ibm.com>
+L: linux-integrity@vger.kernel.org
+L: keyrings@vger.kernel.org
+S: Supported
+F: include/keys/trusted_pkwm.h
+F: security/keys/trusted-keys/trusted_pkwm.c
+
KEYS-TRUSTED-TEE
M: Sumit Garg <sumit.garg@kernel.org>
L: linux-integrity@vger.kernel.org
diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h
index 4eb64548a74f..03527162613f 100644
--- a/include/keys/trusted-type.h
+++ b/include/keys/trusted-type.h
@@ -19,7 +19,11 @@
#define MIN_KEY_SIZE 32
#define MAX_KEY_SIZE 128
-#define MAX_BLOB_SIZE 512
+#if IS_ENABLED(CONFIG_TRUSTED_KEYS_PKWM)
+#define MAX_BLOB_SIZE 1152
+#else
+#define MAX_BLOB_SIZE 512
+#endif
#define MAX_PCRINFO_SIZE 64
#define MAX_DIGEST_SIZE 64
@@ -46,6 +50,7 @@ struct trusted_key_options {
uint32_t policydigest_len;
unsigned char policydigest[MAX_DIGEST_SIZE];
uint32_t policyhandle;
+ void *private;
};
struct trusted_key_ops {
diff --git a/include/keys/trusted_pkwm.h b/include/keys/trusted_pkwm.h
new file mode 100644
index 000000000000..4035b9776394
--- /dev/null
+++ b/include/keys/trusted_pkwm.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PKWM_TRUSTED_KEY_H
+#define __PKWM_TRUSTED_KEY_H
+
+#include <keys/trusted-type.h>
+#include <linux/bitops.h>
+#include <linux/printk.h>
+
+extern struct trusted_key_ops pkwm_trusted_key_ops;
+
+struct trusted_pkwm_options {
+ u16 wrap_flags;
+};
+
+static inline void dump_options(struct trusted_key_options *o)
+{
+ const struct trusted_pkwm_options *pkwm;
+ bool sb_audit_or_enforce_bit;
+ bool sb_enforce_bit;
+
+ pkwm = o->private;
+ sb_audit_or_enforce_bit = pkwm->wrap_flags & BIT(0);
+ sb_enforce_bit = pkwm->wrap_flags & BIT(1);
+
+ if (sb_audit_or_enforce_bit)
+ pr_debug("secure boot mode required: audit or enforce");
+ else if (sb_enforce_bit)
+ pr_debug("secure boot mode required: enforce");
+ else
+ pr_debug("secure boot mode required: disabled");
+}
+
+#endif
diff --git a/security/keys/trusted-keys/Kconfig b/security/keys/trusted-keys/Kconfig
index 204a68c1429d..9e00482d886a 100644
--- a/security/keys/trusted-keys/Kconfig
+++ b/security/keys/trusted-keys/Kconfig
@@ -46,6 +46,14 @@ config TRUSTED_KEYS_DCP
help
Enable use of NXP's DCP (Data Co-Processor) as trusted key backend.
+config TRUSTED_KEYS_PKWM
+ bool "PKWM-based trusted keys"
+ depends on PSERIES_PLPKS >= TRUSTED_KEYS
+ default y
+ select HAVE_TRUSTED_KEYS
+ help
+ Enable use of IBM PowerVM Key Wrapping Module (PKWM) as a trusted key backend.
+
if !HAVE_TRUSTED_KEYS
comment "No trust source selected!"
endif
diff --git a/security/keys/trusted-keys/Makefile b/security/keys/trusted-keys/Makefile
index f0f3b27f688b..5fc053a21dad 100644
--- a/security/keys/trusted-keys/Makefile
+++ b/security/keys/trusted-keys/Makefile
@@ -16,3 +16,5 @@ trusted-$(CONFIG_TRUSTED_KEYS_TEE) += trusted_tee.o
trusted-$(CONFIG_TRUSTED_KEYS_CAAM) += trusted_caam.o
trusted-$(CONFIG_TRUSTED_KEYS_DCP) += trusted_dcp.o
+
+trusted-$(CONFIG_TRUSTED_KEYS_PKWM) += trusted_pkwm.o
diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c
index b1680ee53f86..2d328de170e8 100644
--- a/security/keys/trusted-keys/trusted_core.c
+++ b/security/keys/trusted-keys/trusted_core.c
@@ -12,6 +12,7 @@
#include <keys/trusted_caam.h>
#include <keys/trusted_dcp.h>
#include <keys/trusted_tpm.h>
+#include <keys/trusted_pkwm.h>
#include <linux/capability.h>
#include <linux/err.h>
#include <linux/init.h>
@@ -31,7 +32,7 @@ MODULE_PARM_DESC(rng, "Select trusted key RNG");
static char *trusted_key_source;
module_param_named(source, trusted_key_source, charp, 0);
-MODULE_PARM_DESC(source, "Select trusted keys source (tpm, tee, caam or dcp)");
+MODULE_PARM_DESC(source, "Select trusted keys source (tpm, tee, caam, dcp or pkwm)");
static const struct trusted_key_source trusted_key_sources[] = {
#if defined(CONFIG_TRUSTED_KEYS_TPM)
@@ -46,6 +47,9 @@ static const struct trusted_key_source trusted_key_sources[] = {
#if defined(CONFIG_TRUSTED_KEYS_DCP)
{ "dcp", &dcp_trusted_key_ops },
#endif
+#if defined(CONFIG_TRUSTED_KEYS_PKWM)
+ { "pkwm", &pkwm_trusted_key_ops },
+#endif
};
DEFINE_STATIC_CALL_NULL(trusted_key_seal, *trusted_key_sources[0].ops->seal);
diff --git a/security/keys/trusted-keys/trusted_pkwm.c b/security/keys/trusted-keys/trusted_pkwm.c
new file mode 100644
index 000000000000..4f391b77a907
--- /dev/null
+++ b/security/keys/trusted-keys/trusted_pkwm.c
@@ -0,0 +1,190 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2025 IBM Corporation, Srish Srinivasan <ssrish@linux.ibm.com>
+ */
+
+#include <keys/trusted_pkwm.h>
+#include <keys/trusted-type.h>
+#include <linux/build_bug.h>
+#include <linux/key-type.h>
+#include <linux/parser.h>
+#include <asm/plpks.h>
+
+enum {
+ Opt_err,
+ Opt_wrap_flags,
+};
+
+static const match_table_t key_tokens = {
+ {Opt_wrap_flags, "wrap_flags=%s"},
+ {Opt_err, NULL}
+};
+
+static int getoptions(char *datablob, struct trusted_key_options *opt)
+{
+ substring_t args[MAX_OPT_ARGS];
+ char *p = datablob;
+ int token;
+ int res;
+ u16 wrap_flags;
+ unsigned long token_mask = 0;
+ struct trusted_pkwm_options *pkwm;
+
+ if (!datablob)
+ return 0;
+
+ pkwm = opt->private;
+
+ while ((p = strsep(&datablob, " \t"))) {
+ if (*p == '\0' || *p == ' ' || *p == '\t')
+ continue;
+
+ token = match_token(p, key_tokens, args);
+ if (test_and_set_bit(token, &token_mask))
+ return -EINVAL;
+
+ switch (token) {
+ case Opt_wrap_flags:
+ res = kstrtou16(args[0].from, 16, &wrap_flags);
+ if (res < 0 || wrap_flags > 2)
+ return -EINVAL;
+ pkwm->wrap_flags = wrap_flags;
+ break;
+ default:
+ return -EINVAL;
+ }
+ }
+ return 0;
+}
+
+static struct trusted_key_options *trusted_options_alloc(void)
+{
+ struct trusted_key_options *options;
+ struct trusted_pkwm_options *pkwm;
+
+ options = kzalloc(sizeof(*options), GFP_KERNEL);
+
+ if (options) {
+ pkwm = kzalloc(sizeof(*pkwm), GFP_KERNEL);
+
+ if (!pkwm) {
+ kfree_sensitive(options);
+ options = NULL;
+ } else {
+ options->private = pkwm;
+ }
+ }
+
+ return options;
+}
+
+static int trusted_pkwm_seal(struct trusted_key_payload *p, char *datablob)
+{
+ struct trusted_key_options *options = NULL;
+ struct trusted_pkwm_options *pkwm = NULL;
+ u8 *input_buf, *output_buf;
+ u32 output_len, input_len;
+ int rc;
+
+ options = trusted_options_alloc();
+
+ if (!options)
+ return -ENOMEM;
+
+ rc = getoptions(datablob, options);
+ if (rc < 0)
+ goto out;
+ dump_options(options);
+
+ input_len = p->key_len;
+ input_buf = kmalloc(ALIGN(input_len, 4096), GFP_KERNEL);
+ if (!input_buf) {
+ pr_err("Input buffer allocation failed. Returning -ENOMEM.");
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ memcpy(input_buf, p->key, p->key_len);
+
+ pkwm = options->private;
+
+ rc = plpks_wrap_object(&input_buf, input_len, pkwm->wrap_flags,
+ &output_buf, &output_len);
+ if (!rc) {
+ memcpy(p->blob, output_buf, output_len);
+ p->blob_len = output_len;
+ dump_payload(p);
+ } else {
+ pr_err("Wrapping of payload key failed: %d\n", rc);
+ }
+
+ kfree(input_buf);
+ kfree(output_buf);
+
+out:
+ kfree_sensitive(options->private);
+ kfree_sensitive(options);
+ return rc;
+}
+
+static int trusted_pkwm_unseal(struct trusted_key_payload *p, char *datablob)
+{
+ u8 *input_buf, *output_buf;
+ u32 input_len, output_len;
+ int rc;
+
+ input_len = p->blob_len;
+ input_buf = kmalloc(ALIGN(input_len, 4096), GFP_KERNEL);
+ if (!input_buf) {
+ pr_err("Input buffer allocation failed. Returning -ENOMEM.");
+ return -ENOMEM;
+ }
+
+ memcpy(input_buf, p->blob, p->blob_len);
+
+ rc = plpks_unwrap_object(&input_buf, input_len, &output_buf,
+ &output_len);
+ if (!rc) {
+ memcpy(p->key, output_buf, output_len);
+ p->key_len = output_len;
+ dump_payload(p);
+ } else {
+ pr_err("Unwrapping of payload failed: %d\n", rc);
+ }
+
+ kfree(input_buf);
+ kfree(output_buf);
+
+ return rc;
+}
+
+static int trusted_pkwm_init(void)
+{
+ int ret;
+
+ if (!plpks_wrapping_is_supported()) {
+ pr_err("H_PKS_WRAP_OBJECT interface not supported\n");
+ return -ENODEV;
+ }
+
+ ret = plpks_gen_wrapping_key();
+ if (ret) {
+ pr_err("Failed to generate default wrapping key\n");
+ return -EINVAL;
+ }
+
+ return register_key_type(&key_type_trusted);
+}
+
+static void trusted_pkwm_exit(void)
+{
+ unregister_key_type(&key_type_trusted);
+}
+
+struct trusted_key_ops pkwm_trusted_key_ops = {
+ .migratable = 0, /* non-migratable */
+ .init = trusted_pkwm_init,
+ .seal = trusted_pkwm_seal,
+ .unseal = trusted_pkwm_unseal,
+ .exit = trusted_pkwm_exit,
+};
--
2.47.3
^ permalink raw reply related
* [PATCH v5 3/6] pseries/plpks: expose PowerVM wrapping features via the sysfs
From: Srish Srinivasan @ 2026-01-27 14:52 UTC (permalink / raw)
To: linux-integrity, keyrings, linuxppc-dev
Cc: maddy, mpe, npiggin, christophe.leroy, James.Bottomley, jarkko,
zohar, nayna, rnsastry, linux-kernel, linux-security-module,
ssrish
In-Reply-To: <20260127145228.48320-1-ssrish@linux.ibm.com>
Starting with Power11, PowerVM supports a new feature called "Key Wrapping"
that protects user secrets by wrapping them using a hypervisor generated
wrapping key. The status of this feature can be read by the
H_PKS_GET_CONFIG HCALL.
Expose the Power LPAR Platform KeyStore (PLPKS) wrapping features config
via the sysfs file /sys/firmware/plpks/config/wrapping_features.
Signed-off-by: Srish Srinivasan <ssrish@linux.ibm.com>
Reviewed-by: Nayna Jain <nayna@linux.ibm.com>
---
.../ABI/testing/sysfs-firmware-plpks | 8 ++++++++
arch/powerpc/include/asm/hvcall.h | 4 +++-
arch/powerpc/include/asm/plpks.h | 3 +++
arch/powerpc/platforms/pseries/plpks-sysfs.c | 2 ++
arch/powerpc/platforms/pseries/plpks.c | 20 +++++++++++++++++++
5 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/Documentation/ABI/testing/sysfs-firmware-plpks b/Documentation/ABI/testing/sysfs-firmware-plpks
index af0353f34115..cba061e4eee2 100644
--- a/Documentation/ABI/testing/sysfs-firmware-plpks
+++ b/Documentation/ABI/testing/sysfs-firmware-plpks
@@ -48,3 +48,11 @@ Description: Bitmask of flags indicating which algorithms the hypervisor
supports for signed update of objects, represented as a 16 byte
hexadecimal ASCII string. Consult the hypervisor documentation
for what these flags mean.
+
+What: /sys/firmware/plpks/config/wrapping_features
+Date: November 2025
+Contact: Srish Srinivasan <ssrish@linux.ibm.com>
+Description: Bitmask of the wrapping features indicating the wrapping
+ algorithms that are supported for the H_PKS_WRAP_OBJECT requests
+ , represented as a 8 byte hexadecimal ASCII string. Consult the
+ hypervisor documentation for what these flags mean.
diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h
index 9aef16149d92..dff90a7d7f70 100644
--- a/arch/powerpc/include/asm/hvcall.h
+++ b/arch/powerpc/include/asm/hvcall.h
@@ -360,7 +360,9 @@
#define H_GUEST_RUN_VCPU 0x480
#define H_GUEST_COPY_MEMORY 0x484
#define H_GUEST_DELETE 0x488
-#define MAX_HCALL_OPCODE H_GUEST_DELETE
+#define H_PKS_WRAP_OBJECT 0x490
+#define H_PKS_UNWRAP_OBJECT 0x494
+#define MAX_HCALL_OPCODE H_PKS_UNWRAP_OBJECT
/* Scope args for H_SCM_UNBIND_ALL */
#define H_UNBIND_SCOPE_ALL (0x1)
diff --git a/arch/powerpc/include/asm/plpks.h b/arch/powerpc/include/asm/plpks.h
index 8829a13bfda0..8f034588fdf7 100644
--- a/arch/powerpc/include/asm/plpks.h
+++ b/arch/powerpc/include/asm/plpks.h
@@ -23,6 +23,7 @@
#define PLPKS_IMMUTABLE PPC_BIT32(5) // Once written, object cannot be removed
#define PLPKS_TRANSIENT PPC_BIT32(6) // Object does not persist through reboot
#define PLPKS_SIGNEDUPDATE PPC_BIT32(7) // Object can only be modified by signed updates
+#define PLPKS_WRAPPINGKEY PPC_BIT32(8) // Object contains a wrapping key
#define PLPKS_HVPROVISIONED PPC_BIT32(28) // Hypervisor has provisioned this object
// Signature algorithm flags from signed_update_algorithms
@@ -103,6 +104,8 @@ u32 plpks_get_maxlargeobjectsize(void);
u64 plpks_get_signedupdatealgorithms(void);
+u64 plpks_get_wrappingfeatures(void);
+
u16 plpks_get_passwordlen(void);
void plpks_early_init_devtree(void);
diff --git a/arch/powerpc/platforms/pseries/plpks-sysfs.c b/arch/powerpc/platforms/pseries/plpks-sysfs.c
index 01d526185783..c2ebcbb41ae3 100644
--- a/arch/powerpc/platforms/pseries/plpks-sysfs.c
+++ b/arch/powerpc/platforms/pseries/plpks-sysfs.c
@@ -30,6 +30,7 @@ PLPKS_CONFIG_ATTR(used_space, "%u\n", plpks_get_usedspace);
PLPKS_CONFIG_ATTR(supported_policies, "%08x\n", plpks_get_supportedpolicies);
PLPKS_CONFIG_ATTR(signed_update_algorithms, "%016llx\n",
plpks_get_signedupdatealgorithms);
+PLPKS_CONFIG_ATTR(wrapping_features, "%016llx\n", plpks_get_wrappingfeatures);
static const struct attribute *config_attrs[] = {
&attr_version.attr,
@@ -38,6 +39,7 @@ static const struct attribute *config_attrs[] = {
&attr_used_space.attr,
&attr_supported_policies.attr,
&attr_signed_update_algorithms.attr,
+ &attr_wrapping_features.attr,
NULL,
};
diff --git a/arch/powerpc/platforms/pseries/plpks.c b/arch/powerpc/platforms/pseries/plpks.c
index 03722fabf9c3..4a08f51537c8 100644
--- a/arch/powerpc/platforms/pseries/plpks.c
+++ b/arch/powerpc/platforms/pseries/plpks.c
@@ -38,6 +38,7 @@ static u32 usedspace;
static u32 supportedpolicies;
static u32 maxlargeobjectsize;
static u64 signedupdatealgorithms;
+static u64 wrappingfeatures;
struct plpks_auth {
u8 version;
@@ -248,6 +249,7 @@ static int _plpks_get_config(void)
__be32 supportedpolicies;
__be32 maxlargeobjectsize;
__be64 signedupdatealgorithms;
+ __be64 wrappingfeatures;
u8 rsvd1[476];
} __packed * config;
size_t size;
@@ -280,6 +282,7 @@ static int _plpks_get_config(void)
supportedpolicies = be32_to_cpu(config->supportedpolicies);
maxlargeobjectsize = be32_to_cpu(config->maxlargeobjectsize);
signedupdatealgorithms = be64_to_cpu(config->signedupdatealgorithms);
+ wrappingfeatures = be64_to_cpu(config->wrappingfeatures);
// Validate that the numbers we get back match the requirements of the spec
if (maxpwsize < 32) {
@@ -472,6 +475,23 @@ u64 plpks_get_signedupdatealgorithms(void)
return signedupdatealgorithms;
}
+/**
+ * plpks_get_wrappingfeatures() - Returns a bitmask of the wrapping features
+ * supported by the hypervisor.
+ *
+ * Successful execution of the H_PKS_GET_CONFIG HCALL during initialization
+ * reads a bitmask of the wrapping features supported by the hypervisor into the
+ * file local static wrappingfeatures variable. This is valid only when the
+ * PLPKS config structure version >= 3.
+ *
+ * Return:
+ * bitmask of the wrapping features supported by the hypervisor
+ */
+u64 plpks_get_wrappingfeatures(void)
+{
+ return wrappingfeatures;
+}
+
/**
* plpks_get_passwordlen() - Get the length of the PLPKS password in bytes.
*
--
2.47.3
^ permalink raw reply related
* [PATCH v5 2/6] powerpc/pseries: move the PLPKS config inside its own sysfs directory
From: Srish Srinivasan @ 2026-01-27 14:52 UTC (permalink / raw)
To: linux-integrity, keyrings, linuxppc-dev
Cc: maddy, mpe, npiggin, christophe.leroy, James.Bottomley, jarkko,
zohar, nayna, rnsastry, linux-kernel, linux-security-module,
ssrish
In-Reply-To: <20260127145228.48320-1-ssrish@linux.ibm.com>
The /sys/firmware/secvar/config directory represents Power LPAR Platform
KeyStore (PLPKS) configuration properties such as max_object_size, signed_
update_algorithms, supported_policies, total_size, used_space, and version.
These attributes describe the PLPKS, and not the secure boot variables
(secvars).
Create /sys/firmware/plpks directory and move the PLPKS config inside this
directory. For backwards compatibility, create a soft link from the secvar
sysfs directory to this config and emit a warning stating that the older
sysfs path has been deprecated. Separate out the plpks specific
documentation from secvar.
Signed-off-by: Srish Srinivasan <ssrish@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Nayna Jain <nayna@linux.ibm.com>
---
.../ABI/testing/sysfs-firmware-plpks | 50 ++++++++++
Documentation/ABI/testing/sysfs-secvar | 65 -------------
arch/powerpc/include/asm/plpks.h | 5 +
arch/powerpc/include/asm/secvar.h | 1 -
arch/powerpc/kernel/secvar-sysfs.c | 21 ++---
arch/powerpc/platforms/pseries/Makefile | 2 +-
arch/powerpc/platforms/pseries/plpks-secvar.c | 29 ------
arch/powerpc/platforms/pseries/plpks-sysfs.c | 94 +++++++++++++++++++
8 files changed, 156 insertions(+), 111 deletions(-)
create mode 100644 Documentation/ABI/testing/sysfs-firmware-plpks
create mode 100644 arch/powerpc/platforms/pseries/plpks-sysfs.c
diff --git a/Documentation/ABI/testing/sysfs-firmware-plpks b/Documentation/ABI/testing/sysfs-firmware-plpks
new file mode 100644
index 000000000000..af0353f34115
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-firmware-plpks
@@ -0,0 +1,50 @@
+What: /sys/firmware/plpks/config
+Date: February 2023
+Contact: Nayna Jain <nayna@linux.ibm.com>
+Description: This optional directory contains read-only config attributes as
+ defined by the PLPKS implementation. All data is in ASCII
+ format.
+
+What: /sys/firmware/plpks/config/version
+Date: February 2023
+Contact: Nayna Jain <nayna@linux.ibm.com>
+Description: Config version as reported by the hypervisor in ASCII decimal
+ format.
+
+What: /sys/firmware/plpks/config/max_object_size
+Date: February 2023
+Contact: Nayna Jain <nayna@linux.ibm.com>
+Description: Maximum allowed size of objects in the keystore in bytes,
+ represented in ASCII decimal format.
+
+ This is not necessarily the same as the max size that can be
+ written to an update file as writes can contain more than
+ object data, you should use the size of the update file for
+ that purpose.
+
+What: /sys/firmware/plpks/config/total_size
+Date: February 2023
+Contact: Nayna Jain <nayna@linux.ibm.com>
+Description: Total size of the PLPKS in bytes, represented in ASCII decimal
+ format.
+
+What: /sys/firmware/plpks/config/used_space
+Date: February 2023
+Contact: Nayna Jain <nayna@linux.ibm.com>
+Description: Current space consumed by the key store, in bytes, represented
+ in ASCII decimal format.
+
+What: /sys/firmware/plpks/config/supported_policies
+Date: February 2023
+Contact: Nayna Jain <nayna@linux.ibm.com>
+Description: Bitmask of supported policy flags by the hypervisor, represented
+ as an 8 byte hexadecimal ASCII string. Consult the hypervisor
+ documentation for what these flags are.
+
+What: /sys/firmware/plpks/config/signed_update_algorithms
+Date: February 2023
+Contact: Nayna Jain <nayna@linux.ibm.com>
+Description: Bitmask of flags indicating which algorithms the hypervisor
+ supports for signed update of objects, represented as a 16 byte
+ hexadecimal ASCII string. Consult the hypervisor documentation
+ for what these flags mean.
diff --git a/Documentation/ABI/testing/sysfs-secvar b/Documentation/ABI/testing/sysfs-secvar
index 1016967a730f..c52a5fd15709 100644
--- a/Documentation/ABI/testing/sysfs-secvar
+++ b/Documentation/ABI/testing/sysfs-secvar
@@ -63,68 +63,3 @@ Contact: Nayna Jain <nayna@linux.ibm.com>
Description: A write-only file that is used to submit the new value for the
variable. The size of the file represents the maximum size of
the variable data that can be written.
-
-What: /sys/firmware/secvar/config
-Date: February 2023
-Contact: Nayna Jain <nayna@linux.ibm.com>
-Description: This optional directory contains read-only config attributes as
- defined by the secure variable implementation. All data is in
- ASCII format. The directory is only created if the backing
- implementation provides variables to populate it, which at
- present is only PLPKS on the pseries platform.
-
-What: /sys/firmware/secvar/config/version
-Date: February 2023
-Contact: Nayna Jain <nayna@linux.ibm.com>
-Description: Config version as reported by the hypervisor in ASCII decimal
- format.
-
- Currently only provided by PLPKS on the pseries platform.
-
-What: /sys/firmware/secvar/config/max_object_size
-Date: February 2023
-Contact: Nayna Jain <nayna@linux.ibm.com>
-Description: Maximum allowed size of objects in the keystore in bytes,
- represented in ASCII decimal format.
-
- This is not necessarily the same as the max size that can be
- written to an update file as writes can contain more than
- object data, you should use the size of the update file for
- that purpose.
-
- Currently only provided by PLPKS on the pseries platform.
-
-What: /sys/firmware/secvar/config/total_size
-Date: February 2023
-Contact: Nayna Jain <nayna@linux.ibm.com>
-Description: Total size of the PLPKS in bytes, represented in ASCII decimal
- format.
-
- Currently only provided by PLPKS on the pseries platform.
-
-What: /sys/firmware/secvar/config/used_space
-Date: February 2023
-Contact: Nayna Jain <nayna@linux.ibm.com>
-Description: Current space consumed by the key store, in bytes, represented
- in ASCII decimal format.
-
- Currently only provided by PLPKS on the pseries platform.
-
-What: /sys/firmware/secvar/config/supported_policies
-Date: February 2023
-Contact: Nayna Jain <nayna@linux.ibm.com>
-Description: Bitmask of supported policy flags by the hypervisor,
- represented as an 8 byte hexadecimal ASCII string. Consult the
- hypervisor documentation for what these flags are.
-
- Currently only provided by PLPKS on the pseries platform.
-
-What: /sys/firmware/secvar/config/signed_update_algorithms
-Date: February 2023
-Contact: Nayna Jain <nayna@linux.ibm.com>
-Description: Bitmask of flags indicating which algorithms the hypervisor
- supports for signed update of objects, represented as a 16 byte
- hexadecimal ASCII string. Consult the hypervisor documentation
- for what these flags mean.
-
- Currently only provided by PLPKS on the pseries platform.
diff --git a/arch/powerpc/include/asm/plpks.h b/arch/powerpc/include/asm/plpks.h
index f303922bf622..8829a13bfda0 100644
--- a/arch/powerpc/include/asm/plpks.h
+++ b/arch/powerpc/include/asm/plpks.h
@@ -13,6 +13,7 @@
#include <linux/types.h>
#include <linux/list.h>
+#include <linux/kobject.h>
// Object policy flags from supported_policies
#define PLPKS_OSSECBOOTAUDIT PPC_BIT32(1) // OS secure boot must be audit/enforce
@@ -107,11 +108,15 @@ u16 plpks_get_passwordlen(void);
void plpks_early_init_devtree(void);
int plpks_populate_fdt(void *fdt);
+
+int plpks_config_create_softlink(struct kobject *from);
#else // CONFIG_PSERIES_PLPKS
static inline bool plpks_is_available(void) { return false; }
static inline u16 plpks_get_passwordlen(void) { BUILD_BUG(); }
static inline void plpks_early_init_devtree(void) { }
static inline int plpks_populate_fdt(void *fdt) { BUILD_BUG(); }
+static inline int plpks_config_create_softlink(struct kobject *from)
+ { return 0; }
#endif // CONFIG_PSERIES_PLPKS
#endif // _ASM_POWERPC_PLPKS_H
diff --git a/arch/powerpc/include/asm/secvar.h b/arch/powerpc/include/asm/secvar.h
index 4828e0ab7e3c..fd5006307f2a 100644
--- a/arch/powerpc/include/asm/secvar.h
+++ b/arch/powerpc/include/asm/secvar.h
@@ -20,7 +20,6 @@ struct secvar_operations {
int (*set)(const char *key, u64 key_len, u8 *data, u64 data_size);
ssize_t (*format)(char *buf, size_t bufsize);
int (*max_size)(u64 *max_size);
- const struct attribute **config_attrs;
// NULL-terminated array of fixed variable names
// Only used if get_next() isn't provided
diff --git a/arch/powerpc/kernel/secvar-sysfs.c b/arch/powerpc/kernel/secvar-sysfs.c
index ec900bce0257..4111b21962eb 100644
--- a/arch/powerpc/kernel/secvar-sysfs.c
+++ b/arch/powerpc/kernel/secvar-sysfs.c
@@ -12,6 +12,7 @@
#include <linux/string.h>
#include <linux/of.h>
#include <asm/secvar.h>
+#include <asm/plpks.h>
#define NAME_MAX_SIZE 1024
@@ -145,19 +146,6 @@ static __init int update_kobj_size(void)
return 0;
}
-static __init int secvar_sysfs_config(struct kobject *kobj)
-{
- struct attribute_group config_group = {
- .name = "config",
- .attrs = (struct attribute **)secvar_ops->config_attrs,
- };
-
- if (secvar_ops->config_attrs)
- return sysfs_create_group(kobj, &config_group);
-
- return 0;
-}
-
static __init int add_var(const char *name)
{
struct kobject *kobj;
@@ -260,12 +248,15 @@ static __init int secvar_sysfs_init(void)
goto err;
}
- rc = secvar_sysfs_config(secvar_kobj);
+ rc = plpks_config_create_softlink(secvar_kobj);
if (rc) {
- pr_err("Failed to create config directory\n");
+ pr_err("Failed to create softlink to PLPKS config directory");
goto err;
}
+ pr_info("/sys/firmware/secvar/config is now deprecated.\n");
+ pr_info("Will be removed in future versions.\n");
+
if (secvar_ops->get_next)
rc = secvar_sysfs_load();
else
diff --git a/arch/powerpc/platforms/pseries/Makefile b/arch/powerpc/platforms/pseries/Makefile
index 931ebaa474c8..3ced289a675b 100644
--- a/arch/powerpc/platforms/pseries/Makefile
+++ b/arch/powerpc/platforms/pseries/Makefile
@@ -30,7 +30,7 @@ obj-$(CONFIG_PAPR_SCM) += papr_scm.o
obj-$(CONFIG_PPC_SPLPAR) += vphn.o
obj-$(CONFIG_PPC_SVM) += svm.o
obj-$(CONFIG_FA_DUMP) += rtas-fadump.o
-obj-$(CONFIG_PSERIES_PLPKS) += plpks.o
+obj-$(CONFIG_PSERIES_PLPKS) += plpks.o plpks-sysfs.o
obj-$(CONFIG_PPC_SECURE_BOOT) += plpks-secvar.o
obj-$(CONFIG_PSERIES_PLPKS_SED) += plpks_sed_ops.o
obj-$(CONFIG_SUSPEND) += suspend.o
diff --git a/arch/powerpc/platforms/pseries/plpks-secvar.c b/arch/powerpc/platforms/pseries/plpks-secvar.c
index f9e9cc40c9d0..a50ff6943d80 100644
--- a/arch/powerpc/platforms/pseries/plpks-secvar.c
+++ b/arch/powerpc/platforms/pseries/plpks-secvar.c
@@ -20,33 +20,6 @@
#include <asm/secvar.h>
#include <asm/plpks.h>
-// Config attributes for sysfs
-#define PLPKS_CONFIG_ATTR(name, fmt, func) \
- static ssize_t name##_show(struct kobject *kobj, \
- struct kobj_attribute *attr, \
- char *buf) \
- { \
- return sysfs_emit(buf, fmt, func()); \
- } \
- static struct kobj_attribute attr_##name = __ATTR_RO(name)
-
-PLPKS_CONFIG_ATTR(version, "%u\n", plpks_get_version);
-PLPKS_CONFIG_ATTR(max_object_size, "%u\n", plpks_get_maxobjectsize);
-PLPKS_CONFIG_ATTR(total_size, "%u\n", plpks_get_totalsize);
-PLPKS_CONFIG_ATTR(used_space, "%u\n", plpks_get_usedspace);
-PLPKS_CONFIG_ATTR(supported_policies, "%08x\n", plpks_get_supportedpolicies);
-PLPKS_CONFIG_ATTR(signed_update_algorithms, "%016llx\n", plpks_get_signedupdatealgorithms);
-
-static const struct attribute *config_attrs[] = {
- &attr_version.attr,
- &attr_max_object_size.attr,
- &attr_total_size.attr,
- &attr_used_space.attr,
- &attr_supported_policies.attr,
- &attr_signed_update_algorithms.attr,
- NULL,
-};
-
static u32 get_policy(const char *name)
{
if ((strcmp(name, "db") == 0) ||
@@ -225,7 +198,6 @@ static const struct secvar_operations plpks_secvar_ops_static = {
.set = plpks_set_variable,
.format = plpks_secvar_format,
.max_size = plpks_max_size,
- .config_attrs = config_attrs,
.var_names = plpks_var_names_static,
};
@@ -234,7 +206,6 @@ static const struct secvar_operations plpks_secvar_ops_dynamic = {
.set = plpks_set_variable,
.format = plpks_secvar_format,
.max_size = plpks_max_size,
- .config_attrs = config_attrs,
.var_names = plpks_var_names_dynamic,
};
diff --git a/arch/powerpc/platforms/pseries/plpks-sysfs.c b/arch/powerpc/platforms/pseries/plpks-sysfs.c
new file mode 100644
index 000000000000..01d526185783
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/plpks-sysfs.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2025 IBM Corporation, Srish Srinivasan <ssrish@linux.ibm.com>
+ *
+ * This code exposes PLPKS config to user via sysfs
+ */
+
+#define pr_fmt(fmt) "plpks-sysfs: "fmt
+
+#include <linux/init.h>
+#include <linux/printk.h>
+#include <linux/types.h>
+#include <asm/machdep.h>
+#include <asm/plpks.h>
+
+/* config attributes for sysfs */
+#define PLPKS_CONFIG_ATTR(name, fmt, func) \
+ static ssize_t name##_show(struct kobject *kobj, \
+ struct kobj_attribute *attr, \
+ char *buf) \
+ { \
+ return sysfs_emit(buf, fmt, func()); \
+ } \
+ static struct kobj_attribute attr_##name = __ATTR_RO(name)
+
+PLPKS_CONFIG_ATTR(version, "%u\n", plpks_get_version);
+PLPKS_CONFIG_ATTR(max_object_size, "%u\n", plpks_get_maxobjectsize);
+PLPKS_CONFIG_ATTR(total_size, "%u\n", plpks_get_totalsize);
+PLPKS_CONFIG_ATTR(used_space, "%u\n", plpks_get_usedspace);
+PLPKS_CONFIG_ATTR(supported_policies, "%08x\n", plpks_get_supportedpolicies);
+PLPKS_CONFIG_ATTR(signed_update_algorithms, "%016llx\n",
+ plpks_get_signedupdatealgorithms);
+
+static const struct attribute *config_attrs[] = {
+ &attr_version.attr,
+ &attr_max_object_size.attr,
+ &attr_total_size.attr,
+ &attr_used_space.attr,
+ &attr_supported_policies.attr,
+ &attr_signed_update_algorithms.attr,
+ NULL,
+};
+
+static struct kobject *plpks_kobj, *plpks_config_kobj;
+
+int plpks_config_create_softlink(struct kobject *from)
+{
+ if (!plpks_config_kobj)
+ return -EINVAL;
+ return sysfs_create_link(from, plpks_config_kobj, "config");
+}
+
+static __init int plpks_sysfs_config(struct kobject *kobj)
+{
+ struct attribute_group config_group = {
+ .name = NULL,
+ .attrs = (struct attribute **)config_attrs,
+ };
+
+ return sysfs_create_group(kobj, &config_group);
+}
+
+static __init int plpks_sysfs_init(void)
+{
+ int rc;
+
+ if (!plpks_is_available())
+ return -ENODEV;
+
+ plpks_kobj = kobject_create_and_add("plpks", firmware_kobj);
+ if (!plpks_kobj) {
+ pr_err("Failed to create plpks kobj\n");
+ return -ENOMEM;
+ }
+
+ plpks_config_kobj = kobject_create_and_add("config", plpks_kobj);
+ if (!plpks_config_kobj) {
+ pr_err("Failed to create plpks config kobj\n");
+ kobject_put(plpks_kobj);
+ return -ENOMEM;
+ }
+
+ rc = plpks_sysfs_config(plpks_config_kobj);
+ if (rc) {
+ pr_err("Failed to create attribute group for plpks config\n");
+ kobject_put(plpks_config_kobj);
+ kobject_put(plpks_kobj);
+ return rc;
+ }
+
+ return 0;
+}
+
+machine_subsys_initcall(pseries, plpks_sysfs_init);
--
2.47.3
^ permalink raw reply related
page: next (older) | prev (newer) | latest
- recent:[subjects (threaded)|topics (new)|topics (active)]
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox