* [PATCH v4 1/6] pseries/plpks: fix kernel-doc comment inconsistencies
From: Srish Srinivasan @ 2026-01-15 10:04 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: <20260115100504.488665-1-ssrish@linux.ibm.com>
Fix issues with comments for all the applicable functions to be
consistent with kernel-doc format. Move them before the function
definition as opposed to the function prototype.
Signed-off-by: Srish Srinivasan <ssrish@linux.ibm.com>
---
arch/powerpc/include/asm/plpks.h | 77 ------
arch/powerpc/platforms/pseries/plpks.c | 328 ++++++++++++++++++++++++-
2 files changed, 318 insertions(+), 87 deletions(-)
diff --git a/arch/powerpc/include/asm/plpks.h b/arch/powerpc/include/asm/plpks.h
index 7a84069759b0..f303922bf622 100644
--- a/arch/powerpc/include/asm/plpks.h
+++ b/arch/powerpc/include/asm/plpks.h
@@ -67,122 +67,45 @@ struct plpks_var_name_list {
struct plpks_var_name varlist[];
};
-/**
- * Updates the authenticated variable. It expects NULL as the component.
- */
int plpks_signed_update_var(struct plpks_var *var, u64 flags);
-/**
- * Writes the specified var and its data to PKS.
- * Any caller of PKS driver should present a valid component type for
- * their variable.
- */
int plpks_write_var(struct plpks_var var);
-/**
- * Removes the specified var and its data from PKS.
- */
int plpks_remove_var(char *component, u8 varos,
struct plpks_var_name vname);
-/**
- * Returns the data for the specified os variable.
- *
- * Caller must allocate a buffer in var->data with length in var->datalen.
- * If no buffer is provided, var->datalen will be populated with the object's
- * size.
- */
int plpks_read_os_var(struct plpks_var *var);
-/**
- * Returns the data for the specified firmware variable.
- *
- * Caller must allocate a buffer in var->data with length in var->datalen.
- * If no buffer is provided, var->datalen will be populated with the object's
- * size.
- */
int plpks_read_fw_var(struct plpks_var *var);
-/**
- * Returns the data for the specified bootloader variable.
- *
- * Caller must allocate a buffer in var->data with length in var->datalen.
- * If no buffer is provided, var->datalen will be populated with the object's
- * size.
- */
int plpks_read_bootloader_var(struct plpks_var *var);
-/**
- * Returns if PKS is available on this LPAR.
- */
bool plpks_is_available(void);
-/**
- * Returns version of the Platform KeyStore.
- */
u8 plpks_get_version(void);
-/**
- * Returns hypervisor storage overhead per object, not including the size of
- * the object or label. Only valid for config version >= 2
- */
u16 plpks_get_objoverhead(void);
-/**
- * Returns maximum password size. Must be >= 32 bytes
- */
u16 plpks_get_maxpwsize(void);
-/**
- * Returns maximum object size supported by Platform KeyStore.
- */
u16 plpks_get_maxobjectsize(void);
-/**
- * Returns maximum object label size supported by Platform KeyStore.
- */
u16 plpks_get_maxobjectlabelsize(void);
-/**
- * Returns total size of the configured Platform KeyStore.
- */
u32 plpks_get_totalsize(void);
-/**
- * Returns used space from the total size of the Platform KeyStore.
- */
u32 plpks_get_usedspace(void);
-/**
- * Returns bitmask of policies supported by the hypervisor.
- */
u32 plpks_get_supportedpolicies(void);
-/**
- * Returns maximum byte size of a single object supported by the hypervisor.
- * Only valid for config version >= 3
- */
u32 plpks_get_maxlargeobjectsize(void);
-/**
- * Returns bitmask of signature algorithms supported for signed updates.
- * Only valid for config version >= 3
- */
u64 plpks_get_signedupdatealgorithms(void);
-/**
- * Returns the length of the PLPKS password in bytes.
- */
u16 plpks_get_passwordlen(void);
-/**
- * Called in early init to retrieve and clear the PLPKS password from the DT.
- */
void plpks_early_init_devtree(void);
-/**
- * Populates the FDT with the PLPKS password to prepare for kexec.
- */
int plpks_populate_fdt(void *fdt);
#else // CONFIG_PSERIES_PLPKS
static inline bool plpks_is_available(void) { return false; }
diff --git a/arch/powerpc/platforms/pseries/plpks.c b/arch/powerpc/platforms/pseries/plpks.c
index b1667ed05f98..03722fabf9c3 100644
--- a/arch/powerpc/platforms/pseries/plpks.c
+++ b/arch/powerpc/platforms/pseries/plpks.c
@@ -312,40 +312,107 @@ static int _plpks_get_config(void)
return rc;
}
+/**
+ * plpks_get_version() - Get the version of the PLPKS config structure.
+ *
+ * Successful execution of the H_PKS_GET_CONFIG HCALL during initialization
+ * reads the PLPKS config structure version and saves it in a file local static
+ * version variable.
+ *
+ * Returns: On success the saved PLPKS config structure version is returned, 0
+ * if not.
+ */
u8 plpks_get_version(void)
{
return version;
}
+/**
+ * plpks_get_objoverhead() - Get the hypervisor storage overhead per object.
+ *
+ * Successful execution of the H_PKS_GET_CONFIG HCALL during initialization
+ * reads the per object hypervisor storage overhead in bytes into the local
+ * static objoverhead variable, excluding the size of the object or the label.
+ * This value can be treated as valid only when the PLPKS config structure
+ * version >= 2.
+ *
+ * Returns: If PLPKS config structure version >= 2 then the storage overhead is
+ * returned, 0 otherwise.
+ */
u16 plpks_get_objoverhead(void)
{
return objoverhead;
}
+/**
+ * plpks_get_maxpwsize() - Get the maximum password size.
+ *
+ * Successful execution of the H_PKS_GET_CONFIG HCALL during initialization
+ * reads the maximum password size and checks if it is 32 bytes at the least
+ * before storing it in the local static maxpwsize variable.
+ *
+ * Returns: On success the maximum password size is returned, 0 if not.
+ */
u16 plpks_get_maxpwsize(void)
{
return maxpwsize;
}
+/**
+ * plpks_get_maxobjectsize() - Get the maximum object size supported by the
+ * PLPKS.
+ *
+ * Successful execution of the H_PKS_GET_CONFIG HCALL during initialization
+ * reads the maximum object size into the file local static maxobjsize variable.
+ *
+ * Returns: On success the maximum object size is returned, 0 if not.
+ */
u16 plpks_get_maxobjectsize(void)
{
return maxobjsize;
}
+/**
+ * plpks_get_maxobjectlabelsize() - Get the maximum object label size supported
+ * by the PLPKS.
+ *
+ * Successful execution of the H_PKS_GET_CONFIG HCALL during initialization
+ * reads the maximum object label size into the local static maxobjlabelsize
+ * variable.
+ *
+ * Returns: On success the maximum object label size is returned, 0 if not.
+ */
u16 plpks_get_maxobjectlabelsize(void)
{
return maxobjlabelsize;
}
+/**
+ * plpks_get_totalsize() - Get the total size of the PLPKS that is configured.
+ *
+ * Successful execution of the H_PKS_GET_CONFIG HCALL during initialization
+ * reads the total size of the PLPKS that is configured for the LPAR into the
+ * file local static totalsize variable.
+ *
+ * Returns: On success the total size of the PLPKS configured is returned, 0 if
+ * not.
+ */
u32 plpks_get_totalsize(void)
{
return totalsize;
}
+/**
+ * plpks_get_usedspace() - Get the used space from the total size of the PLPKS.
+ *
+ * Invoke the H_PKS_GET_CONFIG HCALL to refresh the latest value for the used
+ * space as this keeps changing with the creation and removal of objects in the
+ * PLPKS.
+ *
+ * Returns: On success the used space is returned, 0 if not.
+ */
u32 plpks_get_usedspace(void)
{
- // Unlike other config values, usedspace regularly changes as objects
- // are updated, so we need to refresh.
int rc = _plpks_get_config();
if (rc) {
pr_err("Couldn't get config, rc: %d\n", rc);
@@ -354,26 +421,84 @@ u32 plpks_get_usedspace(void)
return usedspace;
}
+/**
+ * plpks_get_supportedpolicies() - Get a bitmask of the policies supported by
+ * the hypervisor.
+ *
+ * Successful execution of the H_PKS_GET_CONFIG HCALL during initialization
+ * reads a bitmask of the policies supported by the hypervisor into the file
+ * local static supportedpolicies variable.
+ *
+ * Returns: On success the bitmask of the policies supported by the hypervisor
+ * are returned, 0 if not.
+ */
u32 plpks_get_supportedpolicies(void)
{
return supportedpolicies;
}
+/**
+ * plpks_get_maxlargeobjectsize() - Get the maximum object size supported for
+ * PLPKS config structure version >= 3
+ *
+ * Successful execution of the H_PKS_GET_CONFIG HCALL during initialization
+ * reads the maximum object size into the local static maxlargeobjectsize
+ * variable for PLPKS config structure version >= 3. This was introduced
+ * starting with PLPKS config structure version 3 to allow for objects of
+ * size >= 64K.
+ *
+ * Returns: If PLPKS config structure version >= 3 then the new maximum object
+ * size is returned, 0 if not.
+ */
u32 plpks_get_maxlargeobjectsize(void)
{
return maxlargeobjectsize;
}
+/**
+ * plpks_get_signedupdatealgorithms() - Get a bitmask of the signature
+ * algorithms supported for signed updates.
+ *
+ * Successful execution of the H_PKS_GET_CONFIG HCALL during initialization
+ * reads a bitmask of the signature algorithms supported for signed updates into
+ * the file local static signedupdatealgorithms variable. This is valid only
+ * when the PLPKS config structure version >= 3.
+ *
+ * Returns: On success the bitmask of the signature algorithms supported for
+ * signed updates is returned, 0 if not.
+ */
u64 plpks_get_signedupdatealgorithms(void)
{
return signedupdatealgorithms;
}
+/**
+ * plpks_get_passwordlen() - Get the length of the PLPKS password in bytes.
+ *
+ * The H_PKS_GEN_PASSWORD HCALL makes the hypervisor generate a random password
+ * for the specified consumer, apply that password to the PLPKS and return it to
+ * the caller. In this process, the password length for the OS consumer is
+ * stored in the local static ospasswordlength variable.
+ *
+ * Returns: On success the password length for the OS consumer in bytes is
+ * returned, 0 if not.
+ */
u16 plpks_get_passwordlen(void)
{
return ospasswordlength;
}
+/**
+ * plpks_is_available() - Get the PLPKS availability status for the LPAR.
+ *
+ * The availability of PLPKS is inferred based upon the successful execution of
+ * the H_PKS_GET_CONFIG HCALL provided the firmware supports this feature. The
+ * H_PKS_GET_CONFIG HCALL reads the configuration and status information related
+ * to the PLPKS. The configuration structure provides a version number to inform
+ * the caller of the supported features.
+ *
+ * Returns: true is returned if PLPKS is available, false if not.
+ */
bool plpks_is_available(void)
{
int rc;
@@ -425,6 +550,35 @@ static int plpks_confirm_object_flushed(struct label *label,
return pseries_status_to_err(rc);
}
+/**
+ * plpks_signed_update_var() - Update the specified authenticated variable.
+ * @var: authenticated variable to be updated
+ * @flags: signed update request operation flags
+ *
+ * The H_PKS_SIGNED_UPDATE HCALL performs a signed update to an object in the
+ * PLPKS. The object must have the signed update policy flag set.
+ *
+ * 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 signed update flags
+ * if invalid input data parameter
+ * if invalid input data len parameter
+ * if invalid continue token parameter
+ * -EPERM if access is denied
+ * -ENOMEM if there is inadequate memory to perform the operation
+ * -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_signed_update_var(struct plpks_var *var, u64 flags)
{
unsigned long retbuf[PLPAR_HCALL9_BUFSIZE] = {0};
@@ -481,6 +635,33 @@ int plpks_signed_update_var(struct plpks_var *var, u64 flags)
return rc;
}
+/**
+ * plpks_write_var() - Write the specified variable and its data to PLPKS.
+ * @var: variable to be written into the PLPKS
+ *
+ * The H_PKS_WRITE_OBJECT HCALL writes an object into the PLPKS. The caller must
+ * provide a valid component type for the variable, and the signed update policy
+ * flag must not be set.
+ *
+ * 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 input data parameter
+ * if invalid input data len parameter
+ * -EPERM if access is denied
+ * -ENOMEM if unable to store the requested object in the space available
+ * -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_write_var(struct plpks_var var)
{
unsigned long retbuf[PLPAR_HCALL_BUFSIZE] = { 0 };
@@ -520,6 +701,30 @@ int plpks_write_var(struct plpks_var var)
return rc;
}
+/**
+ * plpks_remove_var() - Remove the specified variable and its data from PLPKS.
+ * @component: metadata prefix in the object label metadata structure
+ * @varos: metadata OS flags in the object label metadata structure
+ * @vname: object label for the object that needs to be removed
+ *
+ * The H_PKS_REMOVE_OBJECT HCALL removes an object from the PLPKS. The removal
+ * is independent of the policy bits that are set.
+ *
+ * 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
+ * -EPERM if access is denied
+ * -ENOENT if the requested object was not found
+ * -EBUSY if unable to handle the request
+ *
+ * Returns: On success 0 is returned, a negative errno if not.
+ */
int plpks_remove_var(char *component, u8 varos, struct plpks_var_name vname)
{
unsigned long retbuf[PLPAR_HCALL_BUFSIZE] = { 0 };
@@ -619,21 +824,119 @@ static int plpks_read_var(u8 consumer, struct plpks_var *var)
return rc;
}
+/**
+ * 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
+ * H_PKS_READ_OBJECT HCALL reads an object from the PLPKS. The caller must
+ * allocate the buffer var->data and specify the length for this buffer in
+ * var->datalen. If no buffer is provided, var->datalen will be populated with
+ * the requested object's size.
+ *
+ * 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 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 output data parameter
+ * if invalid output data len parameter
+ * -EPERM if access is denied
+ * -ENOENT if the requested object was not found
+ * -EFBIG if the requested object couldn't be
+ * stored in the buffer provided
+ * -EBUSY if unable to handle the request
+ *
+ * Returns: On success 0 is returned, a negative errno if not.
+ */
int plpks_read_os_var(struct plpks_var *var)
{
return plpks_read_var(PLPKS_OS_OWNER, var);
}
+/**
+ * plpks_read_fw_var() - Fetch the data for the specified variable that is
+ * owned by the firmware consumer.
+ * @var: variable to be read from the PLPKS
+ *
+ * The consumer or the owner of the object is the firmware. The
+ * H_PKS_READ_OBJECT HCALL reads an object from the PLPKS. The caller must
+ * allocate the buffer var->data and specify the length for this buffer in
+ * var->datalen. If no buffer is provided, var->datalen will be populated with
+ * the requested object's size.
+ *
+ * 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 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 output data parameter
+ * if invalid output data len parameter
+ * -EPERM if access is denied
+ * -ENOENT if the requested object was not found
+ * -EFBIG if the requested object couldn't be
+ * stored in the buffer provided
+ * -EBUSY if unable to handle the request
+ *
+ * Returns: On success 0 is returned, a negative errno if not.
+ */
int plpks_read_fw_var(struct plpks_var *var)
{
return plpks_read_var(PLPKS_FW_OWNER, var);
}
+/**
+ * plpks_read_bootloader_var() - Fetch the data for the specified variable
+ * owned by the bootloader consumer.
+ * @var: variable to be read from the PLPKS
+ *
+ * The consumer or the owner of the object is the bootloader. The
+ * H_PKS_READ_OBJECT HCALL reads an object from the PLPKS. The caller must
+ * allocate the buffer var->data and specify the length for this buffer in
+ * var->datalen. If no buffer is provided, var->datalen will be populated with
+ * the requested object's size.
+ *
+ * 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 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 output data parameter
+ * if invalid output data len parameter
+ * -EPERM if access is denied
+ * -ENOENT if the requested object was not found
+ * -EFBIG if the requested object couldn't be
+ * stored in the buffer provided
+ * -EBUSY if unable to handle the request
+ *
+ * Returns: On success 0 is returned, a negative errno if not.
+ */
int plpks_read_bootloader_var(struct plpks_var *var)
{
return plpks_read_var(PLPKS_BOOTLOADER_OWNER, var);
}
+/**
+ * plpks_populate_fdt(): Populates the FDT with the PLPKS password to prepare
+ * for kexec.
+ * @fdt: pointer to the device tree blob
+ *
+ * Upon confirming the existence of the chosen node, invoke fdt_setprop to
+ * populate the device tree with the PLPKS password in order to prepare for
+ * kexec.
+ *
+ * Returns: On success 0 is returned, a negative value if not.
+ */
int plpks_populate_fdt(void *fdt)
{
int chosen_offset = fdt_path_offset(fdt, "/chosen");
@@ -647,14 +950,19 @@ int plpks_populate_fdt(void *fdt)
return fdt_setprop(fdt, chosen_offset, "ibm,plpks-pw", ospassword, ospasswordlength);
}
-// Once a password is registered with the hypervisor it cannot be cleared without
-// rebooting the LPAR, so to keep using the PLPKS across kexec boots we need to
-// recover the previous password from the FDT.
-//
-// There are a few challenges here. We don't want the password to be visible to
-// users, so we need to clear it from the FDT. This has to be done in early boot.
-// Clearing it from the FDT would make the FDT's checksum invalid, so we have to
-// manually cause the checksum to be recalculated.
+/**
+ * plpks_early_init_devtree() - Retrieves and clears the PLPKS password from the
+ * DT in early init.
+ *
+ * Once a password is registered with the hypervisor it cannot be cleared
+ * without rebooting the LPAR, so to keep using the PLPKS across kexec boots we
+ * need to recover the previous password from the FDT.
+ *
+ * There are a few challenges here. We don't want the password to be visible to
+ * users, so we need to clear it from the FDT. This has to be done in early
+ * boot. Clearing it from the FDT would make the FDT's checksum invalid, so we
+ * have to manually cause the checksum to be recalculated.
+ */
void __init plpks_early_init_devtree(void)
{
void *fdt = initial_boot_params;
--
2.47.3
^ permalink raw reply related
* [PATCH v4 0/6] Extend "trusted" keys to support a new trust source named the PowerVM Key Wrapping Module (PKWM)
From: Srish Srinivasan @ 2026-01-15 10:04 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
Power11 has introduced a feature called the PowerVM Key Wrapping Module
(PKWM), where PowerVM in combination with Power LPAR Platform KeyStore
(PLPKS) [1] supports a new feature called "Key Wrapping" [2] to protect
user secrets by wrapping them using a hypervisor generated wrapping key.
This wrapping key is an AES-GCM-256 symmetric key that is stored as an
object in the PLPKS. It has policy based protections that prevents it from
being read out or exposed to the user. This wrapping key can then be used
by the OS to wrap or unwrap secrets via hypervisor calls.
This patchset intends to add the PKWM, which is a combination of IBM
PowerVM and PLPKS, as a new trust source for trusted keys. The wrapping key
does not exist by default and its generation is requested by the kernel at
the time of PKWM initialization. This key is then persisted by the PKWM and
is used for wrapping any kernel provided key, and is never exposed to the
user. The kernel is aware of only the label to this wrapping key.
Along with the PKWM implementation, this patchset includes two preparatory
patches: one fixing the kernel-doc inconsistencies in the PLPKS code and
another reorganizing PLPKS config variables in the sysfs.
Changelog:
v4:
* Patch 5:
- Add a per-backend private data pointer in trusted_key_options
to store a pointer to the backend-specific options structure
- Minor clean-up
v3:
* Patch 2:
- Add Mimi's Reviewed-by tag
* Patch 4:
- Minor tweaks to some print statements
- Fix typos
* Patch 5:
- Fix typos
- Add Mimi's Reviewed-by tag
* Patch 6:
- Add Mimi's Reviewed-by tag
v2:
* Patch 2:
- Fix build warning detected by the kernel test bot
* Patch 5:
- Use pr_debug inside dump_options
- Replace policyhande with wrap_flags inside dump_options
- Provide meaningful error messages with error codes
Nayna Jain (1):
docs: trusted-encryped: add PKWM as a new trust source
Srish Srinivasan (5):
pseries/plpks: fix kernel-doc comment inconsistencies
powerpc/pseries: move the PLPKS config inside its own sysfs directory
pseries/plpks: expose PowerVM wrapping features via the sysfs
pseries/plpks: add HCALLs for PowerVM Key Wrapping Module
keys/trusted_keys: establish PKWM as a trusted source
.../ABI/testing/sysfs-firmware-plpks | 58 ++
Documentation/ABI/testing/sysfs-secvar | 65 --
.../admin-guide/kernel-parameters.txt | 1 +
Documentation/arch/powerpc/papr_hcalls.rst | 43 ++
.../security/keys/trusted-encrypted.rst | 50 ++
MAINTAINERS | 9 +
arch/powerpc/include/asm/hvcall.h | 4 +-
arch/powerpc/include/asm/plpks.h | 95 +--
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 | 96 +++
arch/powerpc/platforms/pseries/plpks.c | 686 +++++++++++++++++-
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 +++++
20 files changed, 1205 insertions(+), 201 deletions(-)
create mode 100644 Documentation/ABI/testing/sysfs-firmware-plpks
create mode 100644 arch/powerpc/platforms/pseries/plpks-sysfs.c
create mode 100644 include/keys/trusted_pkwm.h
create mode 100644 security/keys/trusted-keys/trusted_pkwm.c
--
2.47.3
^ permalink raw reply
* [PATCH 2/3] evm: Don't enable fix mode when secure boot is enabled
From: Coiby Xu @ 2026-01-15 0:43 UTC (permalink / raw)
To: linux-integrity
Cc: Heiko Carstens, Mimi Zohar, Roberto Sassu, Roberto Sassu,
Dmitry Kasatkin, Eric Snowberg, Paul Moore, James Morris,
Serge E. Hallyn, open list:SECURITY SUBSYSTEM, open list
In-Reply-To: <20260115004328.194142-1-coxu@redhat.com>
Similar to IMA fix mode, forbid EVM fix mode when secure boot is
enabled.
Reported-and-suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Suggested-by: Roberto Sassu <roberto.sassu@huaweicloud.com>
Signed-off-by: Coiby Xu <coxu@redhat.com>
---
security/integrity/evm/evm_main.c | 24 +++++++++++++++++-------
1 file changed, 17 insertions(+), 7 deletions(-)
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index 73d500a375cb..00bba266231d 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -72,17 +72,25 @@ static struct xattr_list evm_config_default_xattrnames[] = {
LIST_HEAD(evm_config_xattrnames);
+static char *evm_cmdline __initdata;
+core_param(evm, evm_cmdline, charp, 0);
+
static int evm_fixmode __ro_after_init;
-static int __init evm_set_fixmode(char *str)
+static void __init evm_set_fixmode(void)
{
- if (strncmp(str, "fix", 3) == 0)
- evm_fixmode = 1;
- else
- pr_err("invalid \"%s\" mode", str);
+ if (!evm_cmdline)
+ return;
- return 1;
+ if (strncmp(evm_cmdline, "fix", 3) == 0) {
+ if (arch_integrity_get_secureboot()) {
+ pr_info("Secure boot enabled: ignoring evm=fix");
+ return;
+ }
+ evm_fixmode = 1;
+ } else {
+ pr_err("invalid \"%s\" mode", evm_cmdline);
+ }
}
-__setup("evm=", evm_set_fixmode);
static void __init evm_init_config(void)
{
@@ -1119,6 +1127,8 @@ static int __init init_evm(void)
evm_init_config();
+ evm_set_fixmode();
+
error = integrity_init_keyring(INTEGRITY_KEYRING_EVM);
if (error)
goto error;
--
2.52.0
^ permalink raw reply related
* [PATCH 1/3] integrity: Make arch_ima_get_secureboot integrity-wide
From: Coiby Xu @ 2026-01-15 0:43 UTC (permalink / raw)
To: linux-integrity
Cc: Heiko Carstens, Mimi Zohar, Roberto Sassu, Catalin Marinas,
Will Deacon, Madhavan Srinivasan, Michael Ellerman,
Nicholas Piggin, Christophe Leroy (CS GROUP), Vasily Gorbik,
Alexander Gordeev, Christian Borntraeger, Sven Schnelle,
Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen,
maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT), H. Peter Anvin,
Ard Biesheuvel, Roberto Sassu, Dmitry Kasatkin, Eric Snowberg,
Paul Moore, James Morris, Serge E. Hallyn, Jarkko Sakkinen,
moderated list:ARM64 PORT (AARCH64 ARCHITECTURE), open list,
open list:LINUX FOR POWERPC (32-BIT AND 64-BIT),
open list:S390 ARCHITECTURE,
open list:EXTENSIBLE FIRMWARE INTERFACE (EFI),
open list:SECURITY SUBSYSTEM, open list:KEYS/KEYRINGS_INTEGRITY
In-Reply-To: <20260115004328.194142-1-coxu@redhat.com>
EVM and other LSMs need the ability to query the secure boot status of
the system, without directly calling the IMA arch_ima_get_secureboot
function. Refactor the secure boot status check into a general,
integrity-wide function named arch_integrity_get_secureboot.
Define a new Kconfig option CONFIG_INTEGRITY_SECURE_BOOT, which is
automatically configured by the supported architectures. The existing
IMA_SECURE_AND_OR_TRUSTED_BOOT Kconfig loads the architecture specific
IMA policy based on the refactored secure boot status code.
Reported-and-suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Suggested-by: Roberto Sassu <roberto.sassu@huaweicloud.com>
Signed-off-by: Coiby Xu <coxu@redhat.com>
---
arch/arm64/Kconfig | 1 +
arch/powerpc/Kconfig | 1 +
arch/powerpc/kernel/Makefile | 2 +-
arch/powerpc/kernel/ima_arch.c | 5 --
arch/powerpc/kernel/integrity_sb_arch.c | 13 +++++
arch/s390/Kconfig | 1 +
arch/s390/kernel/Makefile | 1 +
arch/s390/kernel/ima_arch.c | 6 --
arch/s390/kernel/integrity_sb_arch.c | 9 +++
arch/x86/Kconfig | 1 +
arch/x86/include/asm/efi.h | 4 +-
arch/x86/platform/efi/efi.c | 2 +-
include/linux/ima.h | 7 +--
include/linux/integrity.h | 8 +++
security/integrity/Kconfig | 6 ++
security/integrity/Makefile | 3 +
security/integrity/efi_secureboot.c | 56 +++++++++++++++++++
security/integrity/ima/ima_appraise.c | 2 +-
security/integrity/ima/ima_efi.c | 47 +---------------
security/integrity/ima/ima_main.c | 4 +-
security/integrity/platform_certs/load_uefi.c | 2 +-
21 files changed, 111 insertions(+), 70 deletions(-)
create mode 100644 arch/powerpc/kernel/integrity_sb_arch.c
create mode 100644 arch/s390/kernel/integrity_sb_arch.c
create mode 100644 security/integrity/efi_secureboot.c
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 93173f0a09c7..4c265b7386bb 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -2427,6 +2427,7 @@ config EFI
select EFI_STUB
select EFI_GENERIC_STUB
imply IMA_SECURE_AND_OR_TRUSTED_BOOT
+ imply INTEGRITY_SECURE_BOOT
default y
help
This option provides support for runtime services provided
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 9537a61ebae0..878f752c35fb 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -1058,6 +1058,7 @@ config PPC_SECURE_BOOT
depends on PPC_POWERNV || PPC_PSERIES
depends on IMA_ARCH_POLICY
imply IMA_SECURE_AND_OR_TRUSTED_BOOT
+ imply INTEGRITY_SECURE_BOOT
select PSERIES_PLPKS if PPC_PSERIES
help
Systems with firmware secure boot enabled need to define security
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 2f0a2e69c607..3bb1fb9a1e0e 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -168,7 +168,7 @@ ifneq ($(CONFIG_PPC_POWERNV)$(CONFIG_PPC_SVM),)
obj-y += ucall.o
endif
-obj-$(CONFIG_PPC_SECURE_BOOT) += secure_boot.o ima_arch.o secvar-ops.o
+obj-$(CONFIG_PPC_SECURE_BOOT) += secure_boot.o ima_arch.o integrity_sb_arch.o secvar-ops.o
obj-$(CONFIG_PPC_SECVAR_SYSFS) += secvar-sysfs.o
# Disable GCOV, KCOV & sanitizers in odd or sensitive code
diff --git a/arch/powerpc/kernel/ima_arch.c b/arch/powerpc/kernel/ima_arch.c
index b7029beed847..0d8892a03526 100644
--- a/arch/powerpc/kernel/ima_arch.c
+++ b/arch/powerpc/kernel/ima_arch.c
@@ -7,11 +7,6 @@
#include <linux/ima.h>
#include <asm/secure_boot.h>
-bool arch_ima_get_secureboot(void)
-{
- return is_ppc_secureboot_enabled();
-}
-
/*
* The "secure_rules" are enabled only on "secureboot" enabled systems.
* These rules verify the file signatures against known good values.
diff --git a/arch/powerpc/kernel/integrity_sb_arch.c b/arch/powerpc/kernel/integrity_sb_arch.c
new file mode 100644
index 000000000000..29f9494391a3
--- /dev/null
+++ b/arch/powerpc/kernel/integrity_sb_arch.c
@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 IBM Corporation
+ * Author: Nayna Jain
+ */
+
+#include <linux/integrity.h>
+#include <asm/secure_boot.h>
+
+bool arch_integrity_get_secureboot(void)
+{
+ return is_ppc_secureboot_enabled();
+}
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 0e5fad5f06ca..db0383b19493 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -78,6 +78,7 @@ config S390
# Note: keep this list sorted alphabetically
#
imply IMA_SECURE_AND_OR_TRUSTED_BOOT
+ imply INTEGRITY_SECURE_BOOT
select ALTERNATE_USER_ADDRESS_SPACE
select ARCH_32BIT_USTAT_F_TINODE
select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index 42c83d60d6fa..ee976a27e677 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -72,6 +72,7 @@ obj-$(CONFIG_KEXEC_FILE) += machine_kexec_file.o kexec_image.o
obj-$(CONFIG_KEXEC_FILE) += kexec_elf.o
obj-$(CONFIG_CERT_STORE) += cert_store.o
obj-$(CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT) += ima_arch.o
+obj-$(CONFIG_INTEGRITY_SECURE_BOOT) += integrity_sb_arch.o
obj-$(CONFIG_PERF_EVENTS) += perf_event.o
obj-$(CONFIG_PERF_EVENTS) += perf_cpum_cf.o perf_cpum_sf.o
diff --git a/arch/s390/kernel/ima_arch.c b/arch/s390/kernel/ima_arch.c
index f3c3e6e1c5d3..6ccbe34ce408 100644
--- a/arch/s390/kernel/ima_arch.c
+++ b/arch/s390/kernel/ima_arch.c
@@ -1,12 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/ima.h>
-#include <asm/boot_data.h>
-
-bool arch_ima_get_secureboot(void)
-{
- return ipl_secure_flag;
-}
const char * const *arch_get_ima_policy(void)
{
diff --git a/arch/s390/kernel/integrity_sb_arch.c b/arch/s390/kernel/integrity_sb_arch.c
new file mode 100644
index 000000000000..208a28cb9961
--- /dev/null
+++ b/arch/s390/kernel/integrity_sb_arch.c
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/integrity.h>
+#include <asm/boot_data.h>
+
+bool arch_integrity_get_secureboot(void)
+{
+ return ipl_secure_flag;
+}
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 80527299f859..5051cc80309a 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -330,6 +330,7 @@ config X86
select FUNCTION_ALIGNMENT_16B if X86_64 || X86_ALIGNMENT_16
select FUNCTION_ALIGNMENT_4B
imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI
+ imply INTEGRITY_SECURE_BOOT if EFI
select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
select ARCH_SUPPORTS_PT_RECLAIM if X86_64
select ARCH_SUPPORTS_SCHED_SMT if SMP
diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index f227a70ac91f..d409f11da331 100644
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -401,9 +401,9 @@ extern int __init efi_memmap_split_count(efi_memory_desc_t *md,
extern void __init efi_memmap_insert(struct efi_memory_map *old_memmap,
void *buf, struct efi_mem_range *mem);
-extern enum efi_secureboot_mode __x86_ima_efi_boot_mode(void);
+enum efi_secureboot_mode __x86_integrity_efi_boot_mode(void);
-#define arch_ima_efi_boot_mode __x86_ima_efi_boot_mode()
+#define arch_integrity_efi_boot_mode __x86_integrity_efi_boot_mode()
#ifdef CONFIG_EFI_RUNTIME_MAP
int efi_get_runtime_map_size(void);
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 463b784499a8..94704858f17a 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -921,7 +921,7 @@ umode_t efi_attr_is_visible(struct kobject *kobj, struct attribute *attr, int n)
return attr->mode;
}
-enum efi_secureboot_mode __x86_ima_efi_boot_mode(void)
+enum efi_secureboot_mode __x86_integrity_efi_boot_mode(void)
{
return boot_params.secure_boot;
}
diff --git a/include/linux/ima.h b/include/linux/ima.h
index 8e29cb4e6a01..fc0ce1e27a2f 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -11,6 +11,7 @@
#include <linux/fs.h>
#include <linux/security.h>
#include <linux/kexec.h>
+#include <linux/integrity.h>
#include <crypto/hash_info.h>
struct linux_binprm;
@@ -72,14 +73,8 @@ int __init ima_get_kexec_buffer(void **addr, size_t *size);
#endif
#ifdef CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT
-extern bool arch_ima_get_secureboot(void);
extern const char * const *arch_get_ima_policy(void);
#else
-static inline bool arch_ima_get_secureboot(void)
-{
- return false;
-}
-
static inline const char * const *arch_get_ima_policy(void)
{
return NULL;
diff --git a/include/linux/integrity.h b/include/linux/integrity.h
index f5842372359b..39e8961b58dd 100644
--- a/include/linux/integrity.h
+++ b/include/linux/integrity.h
@@ -61,5 +61,13 @@ integrity_inode_attrs_changed(const struct integrity_inode_attributes *attrs,
!inode_eq_iversion(inode, attrs->version));
}
+#ifdef CONFIG_INTEGRITY_SECURE_BOOT
+bool arch_integrity_get_secureboot(void);
+#else
+static inline bool arch_integrity_get_secureboot(void)
+{
+ return false;
+}
+#endif
#endif /* _LINUX_INTEGRITY_H */
diff --git a/security/integrity/Kconfig b/security/integrity/Kconfig
index 916d4f2bfc44..1c3e54df3b73 100644
--- a/security/integrity/Kconfig
+++ b/security/integrity/Kconfig
@@ -97,6 +97,12 @@ config INTEGRITY_CA_MACHINE_KEYRING_MAX
will not be loaded. The remaining MOK keys are loaded into the
.platform keyring.
+config INTEGRITY_SECURE_BOOT
+ bool
+ help
+ This option is selected by architectures to provide secure boot
+ related helper functions.
+
config LOAD_UEFI_KEYS
depends on INTEGRITY_PLATFORM_KEYRING
depends on EFI
diff --git a/security/integrity/Makefile b/security/integrity/Makefile
index 92b63039c654..08622460e6fd 100644
--- a/security/integrity/Makefile
+++ b/security/integrity/Makefile
@@ -18,6 +18,9 @@ integrity-$(CONFIG_LOAD_IPL_KEYS) += platform_certs/load_ipl_s390.o
integrity-$(CONFIG_LOAD_PPC_KEYS) += platform_certs/efi_parser.o \
platform_certs/load_powerpc.o \
platform_certs/keyring_handler.o
+ifeq ($(CONFIG_EFI),y)
+integrity-$(CONFIG_INTEGRITY_SECURE_BOOT) += efi_secureboot.o
+endif
# The relative order of the 'ima' and 'evm' LSMs depends on the order below.
obj-$(CONFIG_IMA) += ima/
obj-$(CONFIG_EVM) += evm/
diff --git a/security/integrity/efi_secureboot.c b/security/integrity/efi_secureboot.c
new file mode 100644
index 000000000000..93d5086217d2
--- /dev/null
+++ b/security/integrity/efi_secureboot.c
@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: GPL-1.0+
+/*
+ * Copyright (C) 2018 IBM Corporation
+ */
+#include <linux/efi.h>
+#include <linux/integrity.h>
+#include <asm/efi.h>
+
+#ifndef arch_integrity_efi_boot_mode
+#define arch_integrity_efi_boot_mode efi_secureboot_mode_unset
+#endif
+
+static enum efi_secureboot_mode get_sb_mode(void)
+{
+ enum efi_secureboot_mode mode;
+
+ if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE)) {
+ pr_info("integrity: secureboot mode unknown, no efi\n");
+ return efi_secureboot_mode_unknown;
+ }
+
+ mode = efi_get_secureboot_mode(efi.get_variable);
+ if (mode == efi_secureboot_mode_disabled)
+ pr_info("integrity: secureboot mode disabled\n");
+ else if (mode == efi_secureboot_mode_unknown)
+ pr_info("integrity: secureboot mode unknown\n");
+ else
+ pr_info("integrity: secureboot mode enabled\n");
+ return mode;
+}
+
+/*
+ * Query secure boot status
+ *
+ * Note don't call this function too early e.g. in __setup hook otherwise the
+ * kernel may hang when calling efi_get_secureboot_mode.
+ *
+ */
+bool arch_integrity_get_secureboot(void)
+{
+ static enum efi_secureboot_mode sb_mode;
+ static bool initialized;
+
+ if (!initialized && efi_enabled(EFI_BOOT)) {
+ sb_mode = arch_integrity_efi_boot_mode;
+
+ if (sb_mode == efi_secureboot_mode_unset)
+ sb_mode = get_sb_mode();
+ initialized = true;
+ }
+
+ if (sb_mode == efi_secureboot_mode_enabled)
+ return true;
+ else
+ return false;
+}
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 5149ff4fd50d..f45106cad443 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -27,7 +27,7 @@ core_param(ima_appraise, ima_appraise_cmdline_default, charp, 0);
void __init ima_appraise_parse_cmdline(void)
{
const char *str = ima_appraise_cmdline_default;
- bool sb_state = arch_ima_get_secureboot();
+ bool sb_state = arch_integrity_get_secureboot();
int appraisal_state = ima_appraise;
if (!str)
diff --git a/security/integrity/ima/ima_efi.c b/security/integrity/ima/ima_efi.c
index 138029bfcce1..d6545ae446c7 100644
--- a/security/integrity/ima/ima_efi.c
+++ b/security/integrity/ima/ima_efi.c
@@ -2,52 +2,8 @@
/*
* Copyright (C) 2018 IBM Corporation
*/
-#include <linux/efi.h>
#include <linux/module.h>
#include <linux/ima.h>
-#include <asm/efi.h>
-
-#ifndef arch_ima_efi_boot_mode
-#define arch_ima_efi_boot_mode efi_secureboot_mode_unset
-#endif
-
-static enum efi_secureboot_mode get_sb_mode(void)
-{
- enum efi_secureboot_mode mode;
-
- if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE)) {
- pr_info("ima: secureboot mode unknown, no efi\n");
- return efi_secureboot_mode_unknown;
- }
-
- mode = efi_get_secureboot_mode(efi.get_variable);
- if (mode == efi_secureboot_mode_disabled)
- pr_info("ima: secureboot mode disabled\n");
- else if (mode == efi_secureboot_mode_unknown)
- pr_info("ima: secureboot mode unknown\n");
- else
- pr_info("ima: secureboot mode enabled\n");
- return mode;
-}
-
-bool arch_ima_get_secureboot(void)
-{
- static enum efi_secureboot_mode sb_mode;
- static bool initialized;
-
- if (!initialized && efi_enabled(EFI_BOOT)) {
- sb_mode = arch_ima_efi_boot_mode;
-
- if (sb_mode == efi_secureboot_mode_unset)
- sb_mode = get_sb_mode();
- initialized = true;
- }
-
- if (sb_mode == efi_secureboot_mode_enabled)
- return true;
- else
- return false;
-}
/* secureboot arch rules */
static const char * const sb_arch_rules[] = {
@@ -67,7 +23,8 @@ static const char * const sb_arch_rules[] = {
const char * const *arch_get_ima_policy(void)
{
- if (IS_ENABLED(CONFIG_IMA_ARCH_POLICY) && arch_ima_get_secureboot()) {
+ if (IS_ENABLED(CONFIG_IMA_ARCH_POLICY) &&
+ arch_integrity_get_secureboot()) {
if (IS_ENABLED(CONFIG_MODULE_SIG))
set_module_sig_enforced();
if (IS_ENABLED(CONFIG_KEXEC_SIG))
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 5770cf691912..3f267557dfbe 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -949,8 +949,8 @@ static int ima_load_data(enum kernel_load_data_id id, bool contents)
switch (id) {
case LOADING_KEXEC_IMAGE:
- if (IS_ENABLED(CONFIG_KEXEC_SIG)
- && arch_ima_get_secureboot()) {
+ if (IS_ENABLED(CONFIG_KEXEC_SIG) &&
+ arch_integrity_get_secureboot()) {
pr_err("impossible to appraise a kernel image without a file descriptor; try using kexec_file_load syscall.\n");
return -EACCES;
}
diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c
index d1fdd113450a..3042a0c536d6 100644
--- a/security/integrity/platform_certs/load_uefi.c
+++ b/security/integrity/platform_certs/load_uefi.c
@@ -212,7 +212,7 @@ static int __init load_uefi_certs(void)
}
/* the MOK/MOKx can not be trusted when secure boot is disabled */
- if (!arch_ima_get_secureboot())
+ if (!arch_integrity_get_secureboot())
return 0;
mokx = get_cert_list(L"MokListXRT", &mok_var, &mokxsize, &status);
--
2.52.0
^ permalink raw reply related
* Re: [PATCH v6 05/11] tpm2-sessions: Remove AUTH_MAX_NAMES
From: Jarkko Sakkinen @ 2026-01-14 15:55 UTC (permalink / raw)
To: ross.philipson
Cc: linux-integrity, Peter Huewe, Jason Gunthorpe, David Howells,
Paul Moore, James Morris, Serge E. Hallyn, open list,
open list:KEYS/KEYRINGS, open list:SECURITY SUBSYSTEM
In-Reply-To: <b19c064b-9dfe-45d6-b23d-1bfaca6afb02@oracle.com>
On Mon, Jan 12, 2026 at 04:22:24PM -0800, ross.philipson@oracle.com wrote:
> On 12/14/25 7:38 AM, Jarkko Sakkinen wrote:
> > In all of the call sites only one session is ever append. Thus, reduce
> > AUTH_MAX_NAMES, which leads into removing constant completely.
> >
> > Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
> > ---
> > drivers/char/tpm/tpm2-sessions.c | 31 +++++++++++--------------------
> > 1 file changed, 11 insertions(+), 20 deletions(-)
> >
> > diff --git a/drivers/char/tpm/tpm2-sessions.c b/drivers/char/tpm/tpm2-sessions.c
> > index 3bc3c31cf512..37570dc088cf 100644
> > --- a/drivers/char/tpm/tpm2-sessions.c
> > +++ b/drivers/char/tpm/tpm2-sessions.c
> > @@ -72,9 +72,6 @@
> > #include <crypto/sha2.h>
> > #include <crypto/utils.h>
> > -/* maximum number of names the TPM must remember for authorization */
> > -#define AUTH_MAX_NAMES 3
> > -
> > #define AES_KEY_BYTES AES_KEYSIZE_128
> > #define AES_KEY_BITS (AES_KEY_BYTES*8)
> > @@ -136,8 +133,8 @@ struct tpm2_auth {
> > * handle, but they are part of the session by name, which
> > * we must compute and remember
> > */
> > - u8 name[AUTH_MAX_NAMES][TPM2_MAX_NAME_SIZE];
> > - u16 name_size_tbl[AUTH_MAX_NAMES];
> > + u8 name[TPM2_MAX_NAME_SIZE];
> > + u16 name_size;
> > };
> > #ifdef CONFIG_TCG_TPM2_HMAC
> > @@ -261,11 +258,14 @@ EXPORT_SYMBOL_GPL(tpm2_read_public);
> > int tpm_buf_append_name(struct tpm_chip *chip, struct tpm_buf *buf,
> > u32 handle, u8 *name, u16 name_size)
> > {
> > -#ifdef CONFIG_TCG_TPM2_HMAC
>
> Removing CONFIG_TCG_TPM2_HMAC here causes a warning during compile since the
> auth variable is only used in the CONFIG_TCG_TPM2_HMAC block below.
Thanks for the remark, I'll look into this.
I should have next week bandwidth to look into your patch set too (still
rebooting from the holidays)
>
> Ross
>
> > struct tpm2_auth *auth;
> > - int slot;
> > int ret;
> > -#endif
> > +
> > + if (tpm_buf_length(buf) != TPM_HEADER_SIZE) {
> > + dev_err(&chip->dev, "too many handles\n");
> > + ret = -EIO;
> > + goto err;
> > + }
> > if (!tpm2_chip_auth(chip)) {
> > tpm_buf_append_handle(chip, buf, handle);
> > @@ -273,12 +273,6 @@ int tpm_buf_append_name(struct tpm_chip *chip, struct tpm_buf *buf,
> > }
> > #ifdef CONFIG_TCG_TPM2_HMAC
> > - slot = (tpm_buf_length(buf) - TPM_HEADER_SIZE) / 4;
> > - if (slot >= AUTH_MAX_NAMES) {
> > - dev_err(&chip->dev, "too many handles\n");
> > - ret = -EIO;
> > - goto err;
> > - }
> > auth = chip->auth;
> > if (auth->session != tpm_buf_length(buf)) {
> > dev_err(&chip->dev, "session state malformed");
> > @@ -287,16 +281,14 @@ int tpm_buf_append_name(struct tpm_chip *chip, struct tpm_buf *buf,
> > }
> > tpm_buf_append_u32(buf, handle);
> > auth->session += 4;
> > - memcpy(auth->name[slot], name, name_size);
> > - auth->name_size_tbl[slot] = name_size;
> > + memcpy(auth->name, name, name_size);
> > + auth->name_size = name_size;
> > #endif
> > return 0;
> > -#ifdef CONFIG_TCG_TPM2_HMAC
> > err:
> > tpm2_end_auth_session(chip);
> > return ret;
> > -#endif
> > }
> > EXPORT_SYMBOL_GPL(tpm_buf_append_name);
> > @@ -665,8 +657,7 @@ int tpm_buf_fill_hmac_session(struct tpm_chip *chip, struct tpm_buf *buf)
> > /* ordinal is already BE */
> > sha256_update(&sctx, (u8 *)&head->ordinal, sizeof(head->ordinal));
> > /* add the handle names */
> > - for (i = 0; i < handles; i++)
> > - sha256_update(&sctx, auth->name[i], auth->name_size_tbl[i]);
> > + sha256_update(&sctx, auth->name, auth->name_size);
> > if (offset_s != tpm_buf_length(buf))
> > sha256_update(&sctx, &buf->data[offset_s],
> > tpm_buf_length(buf) - offset_s);
>
BR, Jarkko
^ permalink raw reply
* Re: [PATCH v3 5/6] keys/trusted_keys: establish PKWM as a trusted source
From: Jarkko Sakkinen @ 2026-01-14 15:02 UTC (permalink / raw)
To: Srish Srinivasan
Cc: linux-integrity, keyrings, linuxppc-dev, maddy, mpe, npiggin,
christophe.leroy, James.Bottomley, zohar, nayna, rnsastry,
linux-kernel, linux-security-module
In-Reply-To: <b5086ef7-6f4c-4e4c-81d2-a6a663ee891e@linux.ibm.com>
On Fri, Jan 09, 2026 at 02:17:52PM +0530, Srish Srinivasan wrote:
> Hi Jarkko,
> thank you for taking a look.
>
> On 1/8/26 6:57 PM, Jarkko Sakkinen wrote:
> > On Tue, Jan 06, 2026 at 08:35:26PM +0530, Srish Srinivasan wrote:
> > > 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>
> > > ---
> > > MAINTAINERS | 9 ++
> > > include/keys/trusted-type.h | 7 +-
> > > include/keys/trusted_pkwm.h | 22 +++
> > > 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 | 168 ++++++++++++++++++++++
> > > 7 files changed, 220 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 a0dd762f5648..ba51eff21a16 100644
> > > --- a/MAINTAINERS
> > > +++ b/MAINTAINERS
> > > @@ -14003,6 +14003,15 @@ 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_plpks.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..45c6c538df22 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;
> > > + uint16_t wrap_flags;
> > > };
> > We should introduce:
> >
> > void *private;
> >
> > And hold backend specific fields there.
> >
> > This patch set does not necessarily have to migrate TPM fields to this
> > new framework, only start a better convention before this turns into
> > a chaos.
>
>
> Sure,
> thanks for bringing this up.
> I will make the required changes in my next version.
Great! TPM fields are where they are more like through history and
evolution than by design. While not required, of course migrating
also them is a most welcome additional patch :-)
BR, Jarkko
^ permalink raw reply
* Re: [PATCH v2 1/5] lsm: Add hook unix_path_connect
From: Paul Moore @ 2026-01-13 23:30 UTC (permalink / raw)
To: Justin Suess
Cc: Günther Noack, Mickaël Salaün, James Morris,
Serge E . Hallyn, linux-security-module, Tingmao Wang,
Samasth Norway Ananda, Matthieu Buffet, Mikhail Ivanov,
konstantin.meskhidze, Demi Marie Obenour, Alyssa Ross, Jann Horn,
Tahera Fahimi, Simon Horman, netdev, Alexander Viro,
Christian Brauner
In-Reply-To: <CAHC9VhSRiHwLEWfFkQdPEwgB4AXKbXzw_+3u=9hPpvUTnu02Bg@mail.gmail.com>
On Tue, Jan 13, 2026 at 5:51 PM Paul Moore <paul@paul-moore.com> wrote:
> On Sat, Jan 10, 2026 at 11:45 AM Justin Suess <utilityemal77@gmail.com> wrote:
> > On 1/10/26 09:32, Günther Noack wrote:
> > > From: Justin Suess <utilityemal77@gmail.com>
> > >
> > > Adds an LSM hook unix_path_connect.
> > >
> > > This hook is called to check the path of a named unix socket before a
> > > connection is initiated.
> > >
> > > Cc: Günther Noack <gnoack3000@gmail.com>
> > > Signed-off-by: Justin Suess <utilityemal77@gmail.com>
> > > ---
> > > include/linux/lsm_hook_defs.h | 4 ++++
> > > include/linux/security.h | 11 +++++++++++
> > > net/unix/af_unix.c | 9 +++++++++
> > > security/security.c | 20 ++++++++++++++++++++
> > > 4 files changed, 44 insertions(+)
>
> ...
>
> > > +#if defined(CONFIG_SECURITY_NETWORK) && defined(CONFIG_SECURITY_PATH)
> > > +/*
> > > + * security_unix_path_connect() - Check if a named AF_UNIX socket can connect
> > > + * @path: path of the socket being connected to
> > > + * @type: type of the socket
> > > + * @flags: flags associated with the socket
> > > + *
> > > + * This hook is called to check permissions before connecting to a named
> > > + * AF_UNIX socket.
> > > + *
> > > + * Return: Returns 0 if permission is granted.
> > > + */
> > > +int security_unix_path_connect(const struct path *path, int type, int flags)
> > > +{
> > > + return call_int_hook(unix_path_connect, path, type, flags);
> > > +}
> > > +EXPORT_SYMBOL(security_unix_path_connect);
>
> ...
>
> > I'm considering renaming this hook to unix_socket_path_lookup, since as Günther
> > pointed out this hook is not just hit on connect, but also on sendmsg.
>
> I'm not bothered too much ...
I forgot to add that I know you're likely going to do another revision
to this patchset to rename the hook, but I would suggest waiting until
the AppArmor folks have had a chance to look at the hook. I want to
make sure the new hook is reasonable and suitably generic for a
path-based LSM, and while I suspect it is, having another set of
path-based LSM eyes review the hook would be a very good thing.
--
paul-moore.com
^ permalink raw reply
* Re: [PATCH v2 1/5] lsm: Add hook unix_path_connect
From: Paul Moore @ 2026-01-13 23:27 UTC (permalink / raw)
To: Christian Brauner
Cc: Günther Noack, Mickaël Salaün, James Morris,
Serge E . Hallyn, Justin Suess, linux-security-module,
Tingmao Wang, Samasth Norway Ananda, Matthieu Buffet,
Mikhail Ivanov, konstantin.meskhidze, Demi Marie Obenour,
Alyssa Ross, Jann Horn, Tahera Fahimi, Simon Horman, netdev,
Alexander Viro
In-Reply-To: <20260113-kerngesund-etage-86de4a21da24@brauner>
On Tue, Jan 13, 2026 at 4:34 AM Christian Brauner <brauner@kernel.org> wrote:
> On Sat, Jan 10, 2026 at 03:32:57PM +0100, Günther Noack wrote:
> > From: Justin Suess <utilityemal77@gmail.com>
> >
> > Adds an LSM hook unix_path_connect.
> >
> > This hook is called to check the path of a named unix socket before a
> > connection is initiated.
> >
> > Cc: Günther Noack <gnoack3000@gmail.com>
> > Signed-off-by: Justin Suess <utilityemal77@gmail.com>
> > ---
> > include/linux/lsm_hook_defs.h | 4 ++++
> > include/linux/security.h | 11 +++++++++++
> > net/unix/af_unix.c | 9 +++++++++
> > security/security.c | 20 ++++++++++++++++++++
> > 4 files changed, 44 insertions(+)
...
> > diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
> > index 55cdebfa0da0..3aabe2d489ae 100644
> > --- a/net/unix/af_unix.c
> > +++ b/net/unix/af_unix.c
> > @@ -1226,6 +1226,15 @@ static struct sock *unix_find_bsd(struct sockaddr_un *sunaddr, int addr_len,
> > if (!S_ISSOCK(inode->i_mode))
> > goto path_put;
> >
> > + /*
> > + * We call the hook because we know that the inode is a socket
> > + * and we hold a valid reference to it via the path.
> > + */
> > + err = security_unix_path_connect(&path, type, flags);
> > + if (err)
> > + goto path_put;
>
> Couldn't we try reflowing the code here so the path is passed ...
It would be good if you could be a bit more specific about your
desires here. Are you talking about changing the
unix_find_other()/unix_find_bsd() code path such that the path is
available to unix_find_other() callers and not limited to the
unix_find_bsd() scope?
> ... to
> security_unix_stream_connect() and security_unix_may_send() so that all
> LSMs get the same data and we don't have to have different LSMs hooks
> into different callpaths that effectively do the same thing.
>
> I mean the objects are even in two completely different states between
> those hooks. Even what type of sockets get a call to the LSM is
> different between those two hooks.
I'm working on the assumption that you are talking about changing the
UNIX socket code so that the path info is available to the existing
_may_send() and _stream_connect() hooks. If that isn't the case, and
you're thinking of something different, disregard my comments below.
In both the unix_dgram_{connect(),sendmsg()}, aka
security_unix_may_send(), cases and the unix_stream_connect(), aka
security_unix_stream_connect(), case the call to unix_find_other() is
done to lookup the other end of the communication channel, which does
seem reasonably consistent to me. Yes, of course, once you start
getting into the specifics of the UNIX socket handling the unix_dgram_
and unix_stream_ cases are very different, including their
corresponding existing LSM hooks, but that doesn't mean in the context
of unix_find_bsd() that security_unix_path_connect() doesn't have
value.
The alternative would be some rather serious surgery in af_unix.c to
persist the path struct from unix_find_bsd() until the later LSM hooks
are executed. It's certainly not impossible, but I'm not sure it is
necessary or desirable at this point in time. LSMs that wish to
connect the information from _unix_path_connect() to either
_unix_stream_connect() or _unix_may_send() can do so today without
needing to substantially change af_unix.c.
--
paul-moore.com
^ permalink raw reply
* Re: [PATCH v2 1/5] lsm: Add hook unix_path_connect
From: Paul Moore @ 2026-01-13 22:51 UTC (permalink / raw)
To: Justin Suess
Cc: Günther Noack, Mickaël Salaün, James Morris,
Serge E . Hallyn, linux-security-module, Tingmao Wang,
Samasth Norway Ananda, Matthieu Buffet, Mikhail Ivanov,
konstantin.meskhidze, Demi Marie Obenour, Alyssa Ross, Jann Horn,
Tahera Fahimi, Simon Horman, netdev, Alexander Viro,
Christian Brauner
In-Reply-To: <4bc22faa-2927-4ef9-b5dc-67a7575177e9@gmail.com>
On Sat, Jan 10, 2026 at 11:45 AM Justin Suess <utilityemal77@gmail.com> wrote:
> On 1/10/26 09:32, Günther Noack wrote:
> > From: Justin Suess <utilityemal77@gmail.com>
> >
> > Adds an LSM hook unix_path_connect.
> >
> > This hook is called to check the path of a named unix socket before a
> > connection is initiated.
> >
> > Cc: Günther Noack <gnoack3000@gmail.com>
> > Signed-off-by: Justin Suess <utilityemal77@gmail.com>
> > ---
> > include/linux/lsm_hook_defs.h | 4 ++++
> > include/linux/security.h | 11 +++++++++++
> > net/unix/af_unix.c | 9 +++++++++
> > security/security.c | 20 ++++++++++++++++++++
> > 4 files changed, 44 insertions(+)
...
> > +#if defined(CONFIG_SECURITY_NETWORK) && defined(CONFIG_SECURITY_PATH)
> > +/*
> > + * security_unix_path_connect() - Check if a named AF_UNIX socket can connect
> > + * @path: path of the socket being connected to
> > + * @type: type of the socket
> > + * @flags: flags associated with the socket
> > + *
> > + * This hook is called to check permissions before connecting to a named
> > + * AF_UNIX socket.
> > + *
> > + * Return: Returns 0 if permission is granted.
> > + */
> > +int security_unix_path_connect(const struct path *path, int type, int flags)
> > +{
> > + return call_int_hook(unix_path_connect, path, type, flags);
> > +}
> > +EXPORT_SYMBOL(security_unix_path_connect);
...
> I'm considering renaming this hook to unix_socket_path_lookup, since as Günther
> pointed out this hook is not just hit on connect, but also on sendmsg.
I'm not bothered too much by this, either _path_connect() or
_path_lookup() is okay; please don't use
security_unix_socket_path_lookup(), that's longer than it needs to be,
if you've got "_unix_" in there we know you're talking about a socket
:)
While I don't want us to do it often, we can always change established
hook names if the names end up being really awful or misleading.
We've done it in the past.
It would be nice if somehow the hook name reflected the fact that it
is called on the "client" side of the connection, and not the "server"
side, but I wouldn't use either of those terms (client or server), and
to be honest I can't think of anything better than _path_lookup() at
the moment.
--
paul-moore.com
^ permalink raw reply
* Re: [PATCH v4 15/17] module: Introduce hash-based integrity checking
From: Sebastian Andrzej Siewior @ 2026-01-13 14:56 UTC (permalink / raw)
To: Thomas Weißschuh
Cc: Nathan Chancellor, Arnd Bergmann, Luis Chamberlain, Petr Pavlu,
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, linux-kbuild,
linux-kernel, linux-arch, linux-modules, linux-security-module,
linux-doc, linuxppc-dev, linux-integrity
In-Reply-To: <20260113-module-hashes-v4-15-0b932db9b56b@weissschuh.net>
On 2026-01-13 13:28:59 [+0100], Thomas Weißschuh wrote:
> --- /dev/null
> +++ b/scripts/modules-merkle-tree.c
> @@ -0,0 +1,467 @@
…
> +static void build_proof(struct mtree *mt, unsigned int n, int fd)
> +{
> + unsigned char cur[EVP_MAX_MD_SIZE];
> + unsigned char tmp[EVP_MAX_MD_SIZE];
This and a few other instances below could be optimized to avoid
hashing. I probably forgot to let you know.
-> https://git.kernel.org/pub/scm/linux/kernel/git/bigeasy/mtree-hashed-mods.git/commit/?id=10b565c123c731da37befe862de13678b7c54877
> + struct file_entry *fe, *fe_sib;
> +
> + fe = &fh_list[n];
> +
> + if ((n & 1) == 0) {
> + /* No pair, hash with itself */
> + if (n + 1 == num_files)
> + fe_sib = fe;
> + else
> + fe_sib = &fh_list[n + 1];
> + } else {
> + fe_sib = &fh_list[n - 1];
> + }
> + /* First comes the node position into the file */
> + write_be_int(fd, n);
> +
> + if ((n & 1) == 0)
> + hash_entry(fe->hash, fe_sib->hash, cur);
> + else
> + hash_entry(fe_sib->hash, fe->hash, cur);
> +
> + /* Next is the sibling hash, followed by hashes in the tree */
> + write_hash(fd, fe_sib->hash);
> +
> + for (unsigned int i = 0; i < mt->levels - 1; i++) {
> + n >>= 1;
> + if ((n & 1) == 0) {
> + void *h;
> +
> + /* No pair, hash with itself */
> + if (n + 1 == mt->entries[i])
> + h = cur;
> + else
> + h = mt->l[i][n + 1].hash;
> +
> + hash_entry(cur, h, tmp);
> + write_hash(fd, h);
> + } else {
> + hash_entry(mt->l[i][n - 1].hash, cur, tmp);
> + write_hash(fd, mt->l[i][n - 1].hash);
> + }
> + memcpy(cur, tmp, hash_size);
> + }
> +
> + /* After all that, the end hash should match the root hash */
> + if (memcmp(cur, mt->l[mt->levels - 1][0].hash, hash_size))
> + errx(1, "hash mismatch");
> +}
Sebastian
^ permalink raw reply
* [PATCH v4 15/17] module: Introduce hash-based integrity checking
From: Thomas Weißschuh @ 2026-01-13 12:28 UTC (permalink / raw)
To: Nathan Chancellor, Arnd Bergmann, Luis Chamberlain, Petr Pavlu,
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, Nicolas Schier,
Christophe Leroy
Cc: 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, Thomas Weißschuh
In-Reply-To: <20260113-module-hashes-v4-0-0b932db9b56b@weissschuh.net>
The current signature-based module integrity checking has some drawbacks
in combination with reproducible builds. Either the module signing key
is generated at build time, which makes the build unreproducible, or a
static signing key is used, which precludes rebuilds by third parties
and makes the whole build and packaging process much more complicated.
The goal is to reach bit-for-bit reproducibility. Excluding certain
parts of the build output from the reproducibility analysis would be
error-prone and force each downstream consumer to introduce new tooling.
Introduce a new mechanism to ensure only well-known modules are loaded
by embedding a merkle tree root of all modules built as part of the full
kernel build into vmlinux.
Non-builtin modules can be validated as before through signatures.
Normally the .ko module files depend on a fully built vmlinux to be
available for modpost validation and BTF generation. With
CONFIG_MODULE_HASHES, vmlinux now depends on the modules
to build a merkle tree. This introduces a dependency cycle which is
impossible to satisfy. Work around this by building the modules during
link-vmlinux.sh, after vmlinux is complete enough for modpost and BTF
but before the final module hashes are
The PKCS7 format which is used for regular module signatures can not
represent Merkle proofs, so a new kind of module signature is
introduced. As this signature type is only ever used for builtin
modules, no compatibility issues can arise.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
.gitignore | 1 +
Documentation/kbuild/reproducible-builds.rst | 5 +-
Makefile | 8 +-
include/asm-generic/vmlinux.lds.h | 11 +
include/linux/module_hashes.h | 25 ++
include/linux/module_signature.h | 1 +
kernel/module/Kconfig | 21 +-
kernel/module/Makefile | 1 +
kernel/module/hashes.c | 92 ++++++
kernel/module/hashes_root.c | 6 +
kernel/module/internal.h | 1 +
kernel/module/main.c | 4 +-
scripts/.gitignore | 1 +
scripts/Makefile | 3 +
scripts/Makefile.modfinal | 11 +
scripts/Makefile.modinst | 13 +
scripts/Makefile.vmlinux | 5 +
scripts/link-vmlinux.sh | 14 +-
scripts/modules-merkle-tree.c | 467 +++++++++++++++++++++++++++
security/lockdown/Kconfig | 2 +-
20 files changed, 685 insertions(+), 7 deletions(-)
diff --git a/.gitignore b/.gitignore
index 3a7241c941f5..299c54083672 100644
--- a/.gitignore
+++ b/.gitignore
@@ -35,6 +35,7 @@
*.lz4
*.lzma
*.lzo
+*.merkle
*.mod
*.mod.c
*.o
diff --git a/Documentation/kbuild/reproducible-builds.rst b/Documentation/kbuild/reproducible-builds.rst
index 96d208e578cd..bfde81e47b2d 100644
--- a/Documentation/kbuild/reproducible-builds.rst
+++ b/Documentation/kbuild/reproducible-builds.rst
@@ -82,7 +82,10 @@ generate a different temporary key for each build, resulting in the
modules being unreproducible. However, including a signing key with
your source would presumably defeat the purpose of signing modules.
-One approach to this is to divide up the build process so that the
+Instead ``CONFIG_MODULE_HASHES`` can be used to embed a static list
+of valid modules to load.
+
+Another approach to this is to divide up the build process so that the
unreproducible parts can be treated as sources:
1. Generate a persistent signing key. Add the certificate for the key
diff --git a/Makefile b/Makefile
index e404e4767944..841772a5a260 100644
--- a/Makefile
+++ b/Makefile
@@ -1588,8 +1588,10 @@ endif
# is an exception.
ifdef CONFIG_DEBUG_INFO_BTF_MODULES
KBUILD_BUILTIN := y
+ifndef CONFIG_MODULE_HASHES
modules: vmlinux
endif
+endif
modules: modules_prepare
@@ -1981,7 +1983,11 @@ modules.order: $(build-dir)
# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
# This is solely useful to speed up test compiles.
modules: modpost
-ifneq ($(KBUILD_MODPOST_NOFINAL),1)
+ifdef CONFIG_MODULE_HASHES
+ifeq ($(MODULE_HASHES_MODPOST_FINAL), 1)
+ $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
+endif
+else ifneq ($(KBUILD_MODPOST_NOFINAL),1)
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
endif
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 8ca130af301f..d3846845e37b 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -508,6 +508,8 @@
\
PRINTK_INDEX \
\
+ MODULE_HASHES \
+ \
/* Kernel symbol table: Normal symbols */ \
__ksymtab : AT(ADDR(__ksymtab) - LOAD_OFFSET) { \
__start___ksymtab = .; \
@@ -918,6 +920,15 @@
#define PRINTK_INDEX
#endif
+#ifdef CONFIG_MODULE_HASHES
+#define MODULE_HASHES \
+ .module_hashes : AT(ADDR(.module_hashes) - LOAD_OFFSET) { \
+ KEEP(*(SORT(.module_hashes))) \
+ }
+#else
+#define MODULE_HASHES
+#endif
+
/*
* Discard .note.GNU-stack, which is emitted as PROGBITS by the compiler.
* Otherwise, the type of .notes section would become PROGBITS instead of NOTES.
diff --git a/include/linux/module_hashes.h b/include/linux/module_hashes.h
new file mode 100644
index 000000000000..de61072627cc
--- /dev/null
+++ b/include/linux/module_hashes.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef _LINUX_MODULE_HASHES_H
+#define _LINUX_MODULE_HASHES_H
+
+#include <linux/compiler_attributes.h>
+#include <linux/types.h>
+#include <crypto/sha2.h>
+
+#define __module_hashes_section __section(".module_hashes")
+#define MODULE_HASHES_HASH_SIZE SHA256_DIGEST_SIZE
+
+struct module_hashes_proof {
+ __be32 pos;
+ u8 hash_sigs[][MODULE_HASHES_HASH_SIZE];
+} __packed;
+
+struct module_hashes_root {
+ u32 levels;
+ u8 hash[MODULE_HASHES_HASH_SIZE];
+};
+
+extern const struct module_hashes_root module_hashes_root;
+
+#endif /* _LINUX_MODULE_HASHES_H */
diff --git a/include/linux/module_signature.h b/include/linux/module_signature.h
index a45ce3b24403..3b510651830d 100644
--- a/include/linux/module_signature.h
+++ b/include/linux/module_signature.h
@@ -18,6 +18,7 @@ enum pkey_id_type {
PKEY_ID_PGP, /* OpenPGP generated key ID */
PKEY_ID_X509, /* X.509 arbitrary subjectKeyIdentifier */
PKEY_ID_PKCS7, /* Signature in PKCS#7 message */
+ PKEY_ID_MERKLE, /* Merkle proof for modules */
};
/*
diff --git a/kernel/module/Kconfig b/kernel/module/Kconfig
index db3b61fb3e73..c00ca830330c 100644
--- a/kernel/module/Kconfig
+++ b/kernel/module/Kconfig
@@ -271,7 +271,7 @@ config MODULE_SIG
inclusion into an initramfs that wants the module size reduced.
config MODULE_SIG_POLICY
- def_bool MODULE_SIG
+ def_bool MODULE_SIG || MODULE_HASHES
config MODULE_SIG_FORCE
bool "Require modules to be validly signed"
@@ -289,7 +289,7 @@ config MODULE_SIG_ALL
modules must be signed manually, using the scripts/sign-file tool.
comment "Do not forget to sign required modules with scripts/sign-file"
- depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
+ depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL && !MODULE_HASHES
choice
prompt "Hash algorithm to sign modules"
@@ -408,6 +408,23 @@ config MODULE_DECOMPRESS
If unsure, say N.
+config MODULE_HASHES
+ bool "Module hash validation"
+ depends on !MODULE_SIG_ALL
+ depends on !IMA_APPRAISE_MODSIG
+ select MODULE_SIG_FORMAT
+ select CRYPTO_LIB_SHA256
+ help
+ Validate modules by their hashes.
+ Only modules built together with the main kernel image can be
+ validated that way.
+
+ This is a reproducible-build compatible alternative to a build-time
+ generated module keyring, as enabled by
+ CONFIG_MODULE_SIG_KEY=certs/signing_key.pem.
+
+ Also see the warning in MODULE_SIG about stripping modules.
+
config MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
bool "Allow loading of modules with missing namespace imports"
help
diff --git a/kernel/module/Makefile b/kernel/module/Makefile
index d9e8759a7b05..dd37aaf4a61a 100644
--- a/kernel/module/Makefile
+++ b/kernel/module/Makefile
@@ -25,3 +25,4 @@ obj-$(CONFIG_KGDB_KDB) += kdb.o
obj-$(CONFIG_MODVERSIONS) += version.o
obj-$(CONFIG_MODULE_UNLOAD_TAINT_TRACKING) += tracking.o
obj-$(CONFIG_MODULE_STATS) += stats.o
+obj-$(CONFIG_MODULE_HASHES) += hashes.o hashes_root.o
diff --git a/kernel/module/hashes.c b/kernel/module/hashes.c
new file mode 100644
index 000000000000..23ca9f66652f
--- /dev/null
+++ b/kernel/module/hashes.c
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Module hash-based integrity checker
+ *
+ * Copyright (C) 2025 Thomas Weißschuh <linux@weissschuh.net>
+ * Copyright (C) 2025 Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
+ */
+
+#define pr_fmt(fmt) "module/hash: " fmt
+
+#include <linux/module_hashes.h>
+#include <linux/module.h>
+#include <linux/unaligned.h>
+
+#include <crypto/sha2.h>
+
+#include "internal.h"
+
+static __init __maybe_unused int module_hashes_init(void)
+{
+ pr_debug("root: levels=%u hash=%*phN\n",
+ module_hashes_root.levels,
+ (int)sizeof(module_hashes_root.hash), module_hashes_root.hash);
+
+ return 0;
+}
+
+#if IS_ENABLED(CONFIG_MODULE_DEBUG)
+early_initcall(module_hashes_init);
+#endif
+
+static void hash_entry(const void *left, const void *right, void *out)
+{
+ struct sha256_ctx ctx;
+ u8 magic = 0x02;
+
+ sha256_init(&ctx);
+ sha256_update(&ctx, &magic, sizeof(magic));
+ sha256_update(&ctx, left, MODULE_HASHES_HASH_SIZE);
+ sha256_update(&ctx, right, MODULE_HASHES_HASH_SIZE);
+ sha256_final(&ctx, out);
+}
+
+static void hash_data(const void *d, size_t len, unsigned int pos, void *out)
+{
+ struct sha256_ctx ctx;
+ u8 magic = 0x01;
+ __be32 pos_be;
+
+ pos_be = cpu_to_be32(pos);
+
+ sha256_init(&ctx);
+ sha256_update(&ctx, &magic, sizeof(magic));
+ sha256_update(&ctx, (const u8 *)&pos_be, sizeof(pos_be));
+ sha256_update(&ctx, d, len);
+ sha256_final(&ctx, out);
+}
+
+static bool module_hashes_verify_proof(u32 pos, const u8 hash_sigs[][MODULE_HASHES_HASH_SIZE],
+ u8 *cur)
+{
+ for (unsigned int i = 0; i < module_hashes_root.levels; i++, pos >>= 1) {
+ if ((pos & 1) == 0)
+ hash_entry(cur, hash_sigs[i], cur);
+ else
+ hash_entry(hash_sigs[i], cur, cur);
+ }
+
+ return !memcmp(cur, module_hashes_root.hash, MODULE_HASHES_HASH_SIZE);
+}
+
+int module_hash_check(struct load_info *info, const u8 *sig, size_t sig_len)
+{
+ u8 modhash[MODULE_HASHES_HASH_SIZE];
+ const struct module_hashes_proof *proof;
+ size_t proof_size;
+ u32 pos;
+
+ proof_size = struct_size(proof, hash_sigs, module_hashes_root.levels);
+
+ if (sig_len != proof_size)
+ return -ENOPKG;
+
+ proof = (const struct module_hashes_proof *)sig;
+ pos = get_unaligned_be32(&proof->pos);
+
+ hash_data(info->hdr, info->len, pos, &modhash);
+
+ if (module_hashes_verify_proof(pos, proof->hash_sigs, modhash))
+ info->sig_ok = true;
+
+ return 0;
+}
diff --git a/kernel/module/hashes_root.c b/kernel/module/hashes_root.c
new file mode 100644
index 000000000000..1abfcd3aa679
--- /dev/null
+++ b/kernel/module/hashes_root.c
@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/module_hashes.h>
+
+/* Blank dummy data. Will be overridden by link-vmlinux.sh */
+const struct module_hashes_root module_hashes_root __module_hashes_section = {};
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index e2d49122c2a1..e22837d3ac76 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -338,6 +338,7 @@ void module_mark_ro_after_init(const Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
const char *secstrings);
int module_sig_check(struct load_info *info, const u8 *sig, size_t sig_len);
+int module_hash_check(struct load_info *info, const u8 *sig, size_t sig_len);
#ifdef CONFIG_DEBUG_KMEMLEAK
void kmemleak_load_module(const struct module *mod, const struct load_info *info);
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 2a28a0ece809..fa30b6387936 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -3362,8 +3362,10 @@ static int module_integrity_check(struct load_info *info, int flags)
if (IS_ENABLED(CONFIG_MODULE_SIG) && sig_type == PKEY_ID_PKCS7) {
err = module_sig_check(info, sig, sig_len);
+ } else if (IS_ENABLED(CONFIG_MODULE_HASHES) && sig_type == PKEY_ID_MERKLE) {
+ err = module_hash_check(info, sig, sig_len);
} else {
- pr_err("module: not signed with expected PKCS#7 message\n");
+ pr_err("module: not signed with signature mechanism\n");
err = -ENOPKG;
}
diff --git a/scripts/.gitignore b/scripts/.gitignore
index 4215c2208f7e..8dad9b0d3b2d 100644
--- a/scripts/.gitignore
+++ b/scripts/.gitignore
@@ -5,6 +5,7 @@
/insert-sys-cert
/kallsyms
/module.lds
+/modules-merkle-tree
/recordmcount
/rustdoc_test_builder
/rustdoc_test_gen
diff --git a/scripts/Makefile b/scripts/Makefile
index 0941e5ce7b57..f539e4d93af7 100644
--- a/scripts/Makefile
+++ b/scripts/Makefile
@@ -11,6 +11,7 @@ hostprogs-always-$(CONFIG_MODULE_SIG_FORMAT) += sign-file
hostprogs-always-$(CONFIG_SYSTEM_EXTRA_CERTIFICATE) += insert-sys-cert
hostprogs-always-$(CONFIG_RUST_KERNEL_DOCTESTS) += rustdoc_test_builder
hostprogs-always-$(CONFIG_RUST_KERNEL_DOCTESTS) += rustdoc_test_gen
+hostprogs-always-$(CONFIG_MODULE_HASHES) += modules-merkle-tree
hostprogs-always-$(CONFIG_TRACEPOINTS) += tracepoint-update
sorttable-objs := sorttable.o elf-parse.o
@@ -36,6 +37,8 @@ HOSTLDLIBS_sorttable = -lpthread
HOSTCFLAGS_asn1_compiler.o = -I$(srctree)/include
HOSTCFLAGS_sign-file.o = $(shell $(HOSTPKG_CONFIG) --cflags libcrypto 2> /dev/null)
HOSTLDLIBS_sign-file = $(shell $(HOSTPKG_CONFIG) --libs libcrypto 2> /dev/null || echo -lcrypto)
+HOSTCFLAGS_modules-merkle-tree.o = $(shell $(HOSTPKG_CONFIG) --cflags libcrypto 2> /dev/null)
+HOSTLDLIBS_modules-merkle-tree = $(shell $(HOSTPKG_CONFIG) --libs libcrypto 2> /dev/null || echo -lcrypto)
ifdef CONFIG_UNWINDER_ORC
ifeq ($(ARCH),x86_64)
diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal
index 930db0524a0a..5b8e94170beb 100644
--- a/scripts/Makefile.modfinal
+++ b/scripts/Makefile.modfinal
@@ -63,7 +63,18 @@ ifdef CONFIG_DEBUG_INFO_BTF_MODULES
endif
+$(call cmd,check_tracepoint)
+quiet_cmd_merkle = MERKLE $@
+ cmd_merkle = $(objtree)/scripts/modules-merkle-tree $@ .ko
+
+.tmp_module_hashes.c: $(modules:%.o=%.ko) $(objtree)/scripts/modules-merkle-tree FORCE
+ $(call cmd,merkle)
+
+ifdef CONFIG_MODULE_HASHES
+__modfinal: .tmp_module_hashes.c
+endif
+
targets += $(modules:%.o=%.ko) $(modules:%.o=%.mod.o) .module-common.o
+targets += $(modules:%.o=%.merkle) .tmp_module_hashes.c
# Add FORCE to the prerequisites of a target to force it to be always rebuilt.
# ---------------------------------------------------------------------------
diff --git a/scripts/Makefile.modinst b/scripts/Makefile.modinst
index 9ba45e5b32b1..ba4343b40497 100644
--- a/scripts/Makefile.modinst
+++ b/scripts/Makefile.modinst
@@ -79,6 +79,12 @@ quiet_cmd_install = INSTALL $@
# as the options to the strip command.
ifdef INSTALL_MOD_STRIP
+ifdef CONFIG_MODULE_HASHES
+ifeq ($(KBUILD_EXTMOD),)
+$(error CONFIG_MODULE_HASHES and INSTALL_MOD_STRIP are mutually exclusive)
+endif
+endif
+
ifeq ($(INSTALL_MOD_STRIP),1)
strip-option := --strip-debug
else
@@ -116,6 +122,13 @@ quiet_cmd_sign :=
cmd_sign := :
endif
+ifeq ($(KBUILD_EXTMOD),)
+ifdef CONFIG_MODULE_HASHES
+quiet_cmd_sign = MERKLE [M] $@
+ cmd_sign = cat $(objtree)/$*.merkle >> $@
+endif
+endif
+
# Create necessary directories
$(foreach dir, $(sort $(dir $(install-y))), $(shell mkdir -p $(dir)))
diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux
index cd788cac9d91..f4e38b953b01 100644
--- a/scripts/Makefile.vmlinux
+++ b/scripts/Makefile.vmlinux
@@ -78,6 +78,11 @@ ifdef CONFIG_BUILDTIME_TABLE_SORT
vmlinux.unstripped: scripts/sorttable
endif
+ifdef CONFIG_MODULE_HASHES
+vmlinux.unstripped: $(objtree)/scripts/modules-merkle-tree
+vmlinux.unstripped: modules.order
+endif
+
# vmlinux
# ---------------------------------------------------------------------------
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 8c98f8645a5c..bfeff1f5753d 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -103,7 +103,7 @@ vmlinux_link()
${ld} ${ldflags} -o ${output} \
${wl}--whole-archive ${objs} ${wl}--no-whole-archive \
${wl}--start-group ${libs} ${wl}--end-group \
- ${kallsymso} ${btf_vmlinux_bin_o} ${arch_vmlinux_o} ${ldlibs}
+ ${kallsymso} ${btf_vmlinux_bin_o} ${module_hashes_o} ${arch_vmlinux_o} ${ldlibs}
}
# generate .BTF typeinfo from DWARF debuginfo
@@ -212,6 +212,7 @@ fi
btf_vmlinux_bin_o=
kallsymso=
+module_hashes_o=
strip_debug=
generate_map=
@@ -315,6 +316,17 @@ if is_enabled CONFIG_BUILDTIME_TABLE_SORT; then
fi
fi
+if is_enabled CONFIG_MODULE_HASHES; then
+ info MAKE modules
+ ${MAKE} -f Makefile MODULE_HASHES_MODPOST_FINAL=1 modules
+ module_hashes_o=.tmp_module_hashes.o
+ info CC ${module_hashes_o}
+ ${CC} ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS} ${KBUILD_CFLAGS} \
+ ${KBUILD_CFLAGS_KERNEL} -fno-lto -c -o "${module_hashes_o}" ".tmp_module_hashes.c"
+ ${OBJCOPY} --dump-section .module_hashes=.tmp_module_hashes.bin ${module_hashes_o}
+ ${OBJCOPY} --update-section .module_hashes=.tmp_module_hashes.bin ${VMLINUX}
+fi
+
# step a (see comment above)
if is_enabled CONFIG_KALLSYMS; then
if ! cmp -s System.map "${kallsyms_sysmap}"; then
diff --git a/scripts/modules-merkle-tree.c b/scripts/modules-merkle-tree.c
new file mode 100644
index 000000000000..a6ec0e21213b
--- /dev/null
+++ b/scripts/modules-merkle-tree.c
@@ -0,0 +1,467 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Compute hashes for modules files and build a merkle tree.
+ *
+ * Copyright (C) 2025 Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
+ * Copyright (C) 2025 Thomas Weißschuh <linux@weissschuh.net>
+ *
+ */
+#define _GNU_SOURCE 1
+#include <arpa/inet.h>
+#include <err.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+#include <sys/stat.h>
+#include <sys/mman.h>
+
+#include <openssl/evp.h>
+#include <openssl/err.h>
+
+#include "ssl-common.h"
+
+static int hash_size;
+static EVP_MD_CTX *ctx;
+
+struct module_signature {
+ uint8_t algo; /* Public-key crypto algorithm [0] */
+ uint8_t hash; /* Digest algorithm [0] */
+ uint8_t id_type; /* Key identifier type [PKEY_ID_PKCS7] */
+ uint8_t signer_len; /* Length of signer's name [0] */
+ uint8_t key_id_len; /* Length of key identifier [0] */
+ uint8_t __pad[3];
+ uint32_t sig_len; /* Length of signature data */
+};
+
+#define PKEY_ID_MERKLE 3
+
+static const char magic_number[] = "~Module signature appended~\n";
+
+struct file_entry {
+ char *name;
+ unsigned int pos;
+ unsigned char hash[EVP_MAX_MD_SIZE];
+};
+
+static struct file_entry *fh_list;
+static size_t num_files;
+
+struct leaf_hash {
+ unsigned char hash[EVP_MAX_MD_SIZE];
+};
+
+struct mtree {
+ struct leaf_hash **l;
+ unsigned int *entries;
+ unsigned int levels;
+};
+
+static inline void *xcalloc(size_t n, size_t size)
+{
+ void *p;
+
+ p = calloc(n, size);
+ if (!p)
+ errx(1, "Memory allocation failed");
+
+ return p;
+}
+
+static void *xmalloc(size_t size)
+{
+ void *p;
+
+ p = malloc(size);
+ if (!p)
+ errx(1, "Memory allocation failed");
+
+ return p;
+}
+
+static inline void *xreallocarray(void *oldp, size_t n, size_t size)
+{
+ void *p;
+
+ p = reallocarray(oldp, n, size);
+ if (!p)
+ errx(1, "Memory allocation failed");
+
+ return p;
+}
+
+static inline char *xasprintf(const char *fmt, ...)
+{
+ va_list ap;
+ char *strp;
+ int ret;
+
+ va_start(ap, fmt);
+ ret = vasprintf(&strp, fmt, ap);
+ va_end(ap);
+ if (ret == -1)
+ err(1, "Memory allocation failed");
+
+ return strp;
+}
+
+static unsigned int get_pow2(unsigned int val)
+{
+ return 31 - __builtin_clz(val);
+}
+
+static unsigned int roundup_pow2(unsigned int val)
+{
+ return 1 << (get_pow2(val - 1) + 1);
+}
+
+static unsigned int log2_roundup(unsigned int val)
+{
+ return get_pow2(roundup_pow2(val));
+}
+
+static void hash_data(void *p, unsigned int pos, size_t size, void *ret_hash)
+{
+ unsigned char magic = 0x01;
+ unsigned int pos_be;
+
+ pos_be = htonl(pos);
+
+ ERR(EVP_DigestInit_ex(ctx, NULL, NULL) != 1, "EVP_DigestInit_ex()");
+ ERR(EVP_DigestUpdate(ctx, &magic, sizeof(magic)) != 1, "EVP_DigestUpdate(magic)");
+ ERR(EVP_DigestUpdate(ctx, &pos_be, sizeof(pos_be)) != 1, "EVP_DigestUpdate(pos)");
+ ERR(EVP_DigestUpdate(ctx, p, size) != 1, "EVP_DigestUpdate(data)");
+ ERR(EVP_DigestFinal_ex(ctx, ret_hash, NULL) != 1, "EVP_DigestFinal_ex()");
+}
+
+static void hash_entry(void *left, void *right, void *ret_hash)
+{
+ int hash_size = EVP_MD_CTX_get_size_ex(ctx);
+ unsigned char magic = 0x02;
+
+ ERR(EVP_DigestInit_ex(ctx, NULL, NULL) != 1, "EVP_DigestInit_ex()");
+ ERR(EVP_DigestUpdate(ctx, &magic, sizeof(magic)) != 1, "EVP_DigestUpdate(magic)");
+ ERR(EVP_DigestUpdate(ctx, left, hash_size) != 1, "EVP_DigestUpdate(left)");
+ ERR(EVP_DigestUpdate(ctx, right, hash_size) != 1, "EVP_DigestUpdate(right)");
+ ERR(EVP_DigestFinal_ex(ctx, ret_hash, NULL) != 1, "EVP_DigestFinal_ex()");
+}
+
+static void hash_file(struct file_entry *fe)
+{
+ struct stat sb;
+ int fd, ret;
+ void *mem;
+
+ fd = open(fe->name, O_RDONLY);
+ if (fd < 0)
+ err(1, "Failed to open %s", fe->name);
+
+ ret = fstat(fd, &sb);
+ if (ret)
+ err(1, "Failed to stat %s", fe->name);
+
+ mem = mmap(NULL, sb.st_size, PROT_READ, MAP_SHARED, fd, 0);
+ close(fd);
+
+ if (mem == MAP_FAILED)
+ err(1, "Failed to mmap %s", fe->name);
+
+ hash_data(mem, fe->pos, sb.st_size, fe->hash);
+
+ munmap(mem, sb.st_size);
+}
+
+static struct mtree *build_merkle(struct file_entry *fh, size_t num)
+{
+ struct mtree *mt;
+ unsigned int le;
+
+ if (!num)
+ return NULL;
+
+ mt = xmalloc(sizeof(*mt));
+ mt->levels = log2_roundup(num);
+
+ mt->l = xcalloc(sizeof(*mt->l), mt->levels);
+
+ mt->entries = xcalloc(sizeof(*mt->entries), mt->levels);
+ le = num / 2;
+ if (num & 1)
+ le++;
+ mt->entries[0] = le;
+ mt->l[0] = xcalloc(sizeof(**mt->l), le);
+
+ /* First level of pairs */
+ for (unsigned int i = 0; i < num; i += 2) {
+ if (i == num - 1) {
+ /* Odd number of files, no pair. Hash with itself */
+ hash_entry(fh[i].hash, fh[i].hash, mt->l[0][i / 2].hash);
+ } else {
+ hash_entry(fh[i].hash, fh[i + 1].hash, mt->l[0][i / 2].hash);
+ }
+ }
+ for (unsigned int i = 1; i < mt->levels; i++) {
+ int odd = 0;
+
+ if (le & 1) {
+ le++;
+ odd++;
+ }
+
+ mt->entries[i] = le / 2;
+ mt->l[i] = xcalloc(sizeof(**mt->l), le);
+
+ for (unsigned int n = 0; n < le; n += 2) {
+ if (n == le - 2 && odd) {
+ /* Odd number of pairs, no pair. Hash with itself */
+ hash_entry(mt->l[i - 1][n].hash, mt->l[i - 1][n].hash,
+ mt->l[i][n / 2].hash);
+ } else {
+ hash_entry(mt->l[i - 1][n].hash, mt->l[i - 1][n + 1].hash,
+ mt->l[i][n / 2].hash);
+ }
+ }
+ le = mt->entries[i];
+ }
+ return mt;
+}
+
+static void free_mtree(struct mtree *mt)
+{
+ if (!mt)
+ return;
+
+ for (unsigned int i = 0; i < mt->levels; i++)
+ free(mt->l[i]);
+
+ free(mt->l);
+ free(mt->entries);
+ free(mt);
+}
+
+static void write_be_int(int fd, unsigned int v)
+{
+ unsigned int be_val = htonl(v);
+
+ if (write(fd, &be_val, sizeof(be_val)) != sizeof(be_val))
+ err(1, "Failed writing to file");
+}
+
+static void write_hash(int fd, const void *h)
+{
+ ssize_t wr;
+
+ wr = write(fd, h, hash_size);
+ if (wr != hash_size)
+ err(1, "Failed writing to file");
+}
+
+static void build_proof(struct mtree *mt, unsigned int n, int fd)
+{
+ unsigned char cur[EVP_MAX_MD_SIZE];
+ unsigned char tmp[EVP_MAX_MD_SIZE];
+ struct file_entry *fe, *fe_sib;
+
+ fe = &fh_list[n];
+
+ if ((n & 1) == 0) {
+ /* No pair, hash with itself */
+ if (n + 1 == num_files)
+ fe_sib = fe;
+ else
+ fe_sib = &fh_list[n + 1];
+ } else {
+ fe_sib = &fh_list[n - 1];
+ }
+ /* First comes the node position into the file */
+ write_be_int(fd, n);
+
+ if ((n & 1) == 0)
+ hash_entry(fe->hash, fe_sib->hash, cur);
+ else
+ hash_entry(fe_sib->hash, fe->hash, cur);
+
+ /* Next is the sibling hash, followed by hashes in the tree */
+ write_hash(fd, fe_sib->hash);
+
+ for (unsigned int i = 0; i < mt->levels - 1; i++) {
+ n >>= 1;
+ if ((n & 1) == 0) {
+ void *h;
+
+ /* No pair, hash with itself */
+ if (n + 1 == mt->entries[i])
+ h = cur;
+ else
+ h = mt->l[i][n + 1].hash;
+
+ hash_entry(cur, h, tmp);
+ write_hash(fd, h);
+ } else {
+ hash_entry(mt->l[i][n - 1].hash, cur, tmp);
+ write_hash(fd, mt->l[i][n - 1].hash);
+ }
+ memcpy(cur, tmp, hash_size);
+ }
+
+ /* After all that, the end hash should match the root hash */
+ if (memcmp(cur, mt->l[mt->levels - 1][0].hash, hash_size))
+ errx(1, "hash mismatch");
+}
+
+static void append_module_signature_magic(int fd, unsigned int sig_len)
+{
+ struct module_signature sig_info = {
+ .id_type = PKEY_ID_MERKLE,
+ .sig_len = htonl(sig_len),
+ };
+
+ if (write(fd, &sig_info, sizeof(sig_info)) < 0)
+ err(1, "write(sig_info) failed");
+
+ if (write(fd, &magic_number, sizeof(magic_number) - 1) < 0)
+ err(1, "write(magic_number) failed");
+}
+
+static void write_merkle_root(struct mtree *mt, const char *fp)
+{
+ char buf[1024];
+ unsigned int levels;
+ unsigned char *h;
+ FILE *f;
+
+ if (mt) {
+ levels = mt->levels;
+ h = mt->l[mt->levels - 1][0].hash;
+ } else {
+ levels = 0;
+ h = xcalloc(1, hash_size);
+ }
+
+ f = fopen(fp, "w");
+ if (!f)
+ err(1, "Failed to create %s", buf);
+
+ fprintf(f, "#include <linux/module_hashes.h>\n\n");
+ fprintf(f, "const struct module_hashes_root module_hashes_root __module_hashes_section = {\n");
+
+ fprintf(f, "\t.levels = %u,\n", levels);
+ fprintf(f, "\t.hash = {");
+ for (unsigned int i = 0; i < hash_size; i++) {
+ char *space = "";
+
+ if (!(i % 8))
+ fprintf(f, "\n\t\t");
+
+ if ((i + 1) % 8)
+ space = " ";
+
+ fprintf(f, "0x%02x,%s", h[i], space);
+ }
+ fprintf(f, "\n\t},");
+
+ fprintf(f, "\n};\n");
+ fclose(f);
+
+ if (!mt)
+ free(h);
+}
+
+static char *xstrdup_replace_suffix(const char *str, const char *new_suffix)
+{
+ const char *current_suffix;
+ size_t base_len;
+
+ current_suffix = strchr(str, '.');
+ if (!current_suffix)
+ errx(1, "No existing suffix in '%s'", str);
+
+ base_len = current_suffix - str;
+
+ return xasprintf("%.*s%s", (int)base_len, str, new_suffix);
+}
+
+static void read_modules_order(const char *fname, const char *suffix)
+{
+ char line[PATH_MAX];
+ FILE *in;
+
+ in = fopen(fname, "r");
+ if (!in)
+ err(1, "fopen(%s)", fname);
+
+ while (fgets(line, PATH_MAX, in)) {
+ struct file_entry *entry;
+
+ fh_list = xreallocarray(fh_list, num_files + 1, sizeof(*fh_list));
+ entry = &fh_list[num_files];
+
+ entry->pos = num_files;
+ entry->name = xstrdup_replace_suffix(line, suffix);
+ hash_file(entry);
+
+ num_files++;
+ }
+
+ fclose(in);
+}
+
+static __attribute__((noreturn))
+void format(void)
+{
+ fprintf(stderr,
+ "Usage: scripts/modules-merkle-tree <root definition>\n");
+ exit(2);
+}
+
+int main(int argc, char *argv[])
+{
+ const EVP_MD *hash_evp;
+ struct mtree *mt;
+
+ if (argc != 3)
+ format();
+
+ hash_evp = EVP_get_digestbyname("sha256");
+ ERR(!hash_evp, "EVP_get_digestbyname");
+
+ ctx = EVP_MD_CTX_new();
+ ERR(!ctx, "EVP_MD_CTX_new()");
+
+ hash_size = EVP_MD_get_size(hash_evp);
+ ERR(hash_size <= 0, "EVP_get_digestbyname");
+
+ if (EVP_DigestInit_ex(ctx, hash_evp, NULL) != 1)
+ ERR(1, "EVP_DigestInit_ex()");
+
+ read_modules_order("modules.order", argv[2]);
+
+ mt = build_merkle(fh_list, num_files);
+ write_merkle_root(mt, argv[1]);
+ for (unsigned int i = 0; i < num_files; i++) {
+ char *signame;
+ int fd;
+
+ signame = xstrdup_replace_suffix(fh_list[i].name, ".merkle");
+
+ fd = open(signame, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+ if (fd < 0)
+ err(1, "Can't create %s", signame);
+
+ build_proof(mt, i, fd);
+ append_module_signature_magic(fd, lseek(fd, 0, SEEK_CUR));
+ close(fd);
+ }
+
+ free_mtree(mt);
+ for (unsigned int i = 0; i < num_files; i++)
+ free(fh_list[i].name);
+ free(fh_list);
+
+ EVP_MD_CTX_free(ctx);
+ return 0;
+}
diff --git a/security/lockdown/Kconfig b/security/lockdown/Kconfig
index 155959205b8e..60b240e3ef1f 100644
--- a/security/lockdown/Kconfig
+++ b/security/lockdown/Kconfig
@@ -1,7 +1,7 @@
config SECURITY_LOCKDOWN_LSM
bool "Basic module for enforcing kernel lockdown"
depends on SECURITY
- depends on !MODULES || MODULE_SIG
+ depends on !MODULES || MODULE_SIG || MODULE_HASHES
help
Build support for an LSM that enforces a coarse kernel lockdown
behaviour.
--
2.52.0
^ permalink raw reply related
* [PATCH v4 06/17] kbuild: add stamp file for vmlinux BTF data
From: Thomas Weißschuh @ 2026-01-13 12:28 UTC (permalink / raw)
To: Nathan Chancellor, Arnd Bergmann, Luis Chamberlain, Petr Pavlu,
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, Nicolas Schier,
Christophe Leroy
Cc: 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, Thomas Weißschuh
In-Reply-To: <20260113-module-hashes-v4-0-0b932db9b56b@weissschuh.net>
The upcoming module hashes functionality will build the modules in
between the generation of the BTF data and the final link of vmlinux.
Having a dependency from the modules on vmlinux would make this
impossible as it would mean having a cyclic dependency.
Break this cyclic dependency by introducing a new target.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
scripts/Makefile.modfinal | 4 ++--
scripts/link-vmlinux.sh | 6 ++++++
2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal
index 149e12ff5700..adfef1e002a9 100644
--- a/scripts/Makefile.modfinal
+++ b/scripts/Makefile.modfinal
@@ -56,8 +56,8 @@ if_changed_except = $(if $(call newer_prereqs_except,$(2))$(cmd-check), \
printf '%s\n' 'savedcmd_$@ := $(make-cmd)' > $(dot-target).cmd, @:)
# Re-generate module BTFs if either module's .ko or vmlinux changed
-%.ko: %.o %.mod.o .module-common.o $(objtree)/scripts/module.lds $(and $(CONFIG_DEBUG_INFO_BTF_MODULES),$(KBUILD_BUILTIN),$(objtree)/vmlinux) FORCE
- +$(call if_changed_except,ld_ko_o,$(objtree)/vmlinux)
+%.ko: %.o %.mod.o .module-common.o $(objtree)/scripts/module.lds $(and $(CONFIG_DEBUG_INFO_BTF_MODULES),$(KBUILD_BUILTIN),$(objtree)/.tmp_vmlinux_btf.stamp) FORCE
+ +$(call if_changed_except,ld_ko_o,$(objtree)/.tmp_vmlinux_btf.stamp)
ifdef CONFIG_DEBUG_INFO_BTF_MODULES
+$(if $(newer-prereqs),$(call cmd,btf_ko))
endif
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 4ab44c73da4d..8c98f8645a5c 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -111,6 +111,7 @@ vmlinux_link()
gen_btf()
{
local btf_data=${1}.btf.o
+ local btf_stamp=.tmp_vmlinux_btf.stamp
info BTF "${btf_data}"
LLVM_OBJCOPY="${OBJCOPY}" ${PAHOLE} -J ${PAHOLE_FLAGS} ${1}
@@ -131,6 +132,11 @@ gen_btf()
fi
printf "${et_rel}" | dd of="${btf_data}" conv=notrunc bs=1 seek=16 status=none
+ info STAMP $btf_stamp
+ if ! cmp --silent $btf_data $btf_stamp; then
+ cp $btf_data $btf_stamp
+ fi
+
btf_vmlinux_bin_o=${btf_data}
}
--
2.52.0
^ permalink raw reply related
* [PATCH v4 16/17] kbuild: move handling of module stripping to Makefile.lib
From: Thomas Weißschuh @ 2026-01-13 12:29 UTC (permalink / raw)
To: Nathan Chancellor, Arnd Bergmann, Luis Chamberlain, Petr Pavlu,
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, Nicolas Schier,
Christophe Leroy
Cc: 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, Thomas Weißschuh
In-Reply-To: <20260113-module-hashes-v4-0-0b932db9b56b@weissschuh.net>
To allow CONFIG_MODULE_HASHES in combination with INSTALL_MOD_STRIP,
this logc will also be used by Makefile.modfinal.
Move it to a shared location to enable reuse.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
scripts/Makefile.lib | 32 ++++++++++++++++++++++++++++++++
scripts/Makefile.modinst | 37 +++++--------------------------------
2 files changed, 37 insertions(+), 32 deletions(-)
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 28a1c08e3b22..7fcf3c43e408 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -474,6 +474,38 @@ define sed-offsets
s:->::; p;}'
endef
+#
+# Module Installation
+#
+quiet_cmd_install_mod = INSTALL $@
+ cmd_install_mod = cp $< $@
+
+# Module Strip
+# ---------------------------------------------------------------------------
+#
+# INSTALL_MOD_STRIP, if defined, will cause modules to be stripped after they
+# are installed. If INSTALL_MOD_STRIP is '1', then the default option
+# --strip-debug will be used. Otherwise, INSTALL_MOD_STRIP value will be used
+# as the options to the strip command.
+ifeq ($(INSTALL_MOD_STRIP),1)
+mod-strip-option := --strip-debug
+else
+mod-strip-option := $(INSTALL_MOD_STRIP)
+endif
+
+# Strip
+ifdef INSTALL_MOD_STRIP
+
+quiet_cmd_strip_mod = STRIP $@
+ cmd_strip_mod = $(STRIP) $(mod-strip-option) $@
+
+else
+
+quiet_cmd_strip_mod =
+ cmd_strip_mod = :
+
+endif
+
# Use filechk to avoid rebuilds when a header changes, but the resulting file
# does not
define filechk_offsets
diff --git a/scripts/Makefile.modinst b/scripts/Makefile.modinst
index ba4343b40497..07380c7233a0 100644
--- a/scripts/Makefile.modinst
+++ b/scripts/Makefile.modinst
@@ -8,6 +8,7 @@ __modinst:
include $(objtree)/include/config/auto.conf
include $(srctree)/scripts/Kbuild.include
+include $(srctree)/scripts/Makefile.lib
install-y :=
@@ -36,7 +37,7 @@ install-y += $(addprefix $(MODLIB)/, modules.builtin modules.builtin.modinfo)
install-$(CONFIG_BUILTIN_MODULE_RANGES) += $(MODLIB)/modules.builtin.ranges
$(addprefix $(MODLIB)/, modules.builtin modules.builtin.modinfo modules.builtin.ranges): $(MODLIB)/%: % FORCE
- $(call cmd,install)
+ $(call cmd,install_mod)
endif
@@ -65,40 +66,12 @@ install-$(CONFIG_MODULES) += $(modules)
__modinst: $(install-y)
@:
-#
-# Installation
-#
-quiet_cmd_install = INSTALL $@
- cmd_install = cp $< $@
-
-# Strip
-#
-# INSTALL_MOD_STRIP, if defined, will cause modules to be stripped after they
-# are installed. If INSTALL_MOD_STRIP is '1', then the default option
-# --strip-debug will be used. Otherwise, INSTALL_MOD_STRIP value will be used
-# as the options to the strip command.
-ifdef INSTALL_MOD_STRIP
-
ifdef CONFIG_MODULE_HASHES
ifeq ($(KBUILD_EXTMOD),)
+ifdef INSTALL_MOD_STRIP
$(error CONFIG_MODULE_HASHES and INSTALL_MOD_STRIP are mutually exclusive)
endif
endif
-
-ifeq ($(INSTALL_MOD_STRIP),1)
-strip-option := --strip-debug
-else
-strip-option := $(INSTALL_MOD_STRIP)
-endif
-
-quiet_cmd_strip = STRIP $@
- cmd_strip = $(STRIP) $(strip-option) $@
-
-else
-
-quiet_cmd_strip =
- cmd_strip = :
-
endif
#
@@ -133,8 +106,8 @@ endif
$(foreach dir, $(sort $(dir $(install-y))), $(shell mkdir -p $(dir)))
$(dst)/%.ko: %.ko FORCE
- $(call cmd,install)
- $(call cmd,strip)
+ $(call cmd,install_mod)
+ $(call cmd,strip_mod)
$(call cmd,sign)
ifdef CONFIG_MODULES
--
2.52.0
^ permalink raw reply related
* [PATCH v4 17/17] kbuild: make CONFIG_MODULE_HASHES compatible with module stripping
From: Thomas Weißschuh @ 2026-01-13 12:29 UTC (permalink / raw)
To: Nathan Chancellor, Arnd Bergmann, Luis Chamberlain, Petr Pavlu,
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, Nicolas Schier,
Christophe Leroy
Cc: 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, Thomas Weißschuh
In-Reply-To: <20260113-module-hashes-v4-0-0b932db9b56b@weissschuh.net>
CONFIG_MODULE_HASHES needs to process the modules at build time in the
exact form they will be loaded at runtime. If the modules are stripped
afterwards they will not be loadable anymore.
Also evaluate INSTALL_MOD_STRIP at build time and build the hashes based
on modules stripped this way.
If users specify inconsistent values of INSTALL_MOD_STRIP between build
and installation time, an error is reported.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
.gitignore | 1 +
kernel/module/Kconfig | 5 +++++
scripts/Makefile.modfinal | 9 +++++++--
scripts/Makefile.modinst | 4 ++--
scripts/Makefile.vmlinux | 1 +
5 files changed, 16 insertions(+), 4 deletions(-)
diff --git a/.gitignore b/.gitignore
index 299c54083672..900251c72ade 100644
--- a/.gitignore
+++ b/.gitignore
@@ -29,6 +29,7 @@
*.gz
*.i
*.ko
+*.ko.stripped
*.lex.c
*.ll
*.lst
diff --git a/kernel/module/Kconfig b/kernel/module/Kconfig
index c00ca830330c..9fd34765ce2c 100644
--- a/kernel/module/Kconfig
+++ b/kernel/module/Kconfig
@@ -425,6 +425,11 @@ config MODULE_HASHES
Also see the warning in MODULE_SIG about stripping modules.
+# To validate the consistency of INSTALL_MOD_STRIP for MODULE_HASHES
+config MODULE_INSTALL_STRIP
+ string
+ default "$(INSTALL_MOD_STRIP)"
+
config MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
bool "Allow loading of modules with missing namespace imports"
help
diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal
index 5b8e94170beb..890724edac69 100644
--- a/scripts/Makefile.modfinal
+++ b/scripts/Makefile.modfinal
@@ -63,10 +63,14 @@ ifdef CONFIG_DEBUG_INFO_BTF_MODULES
endif
+$(call cmd,check_tracepoint)
+%.ko.stripped: %.ko $(wildcard include/config/MODULE_INSTALL_STRIP)
+ $(call cmd,install_mod)
+ $(call cmd,strip_mod)
+
quiet_cmd_merkle = MERKLE $@
- cmd_merkle = $(objtree)/scripts/modules-merkle-tree $@ .ko
+ cmd_merkle = $(objtree)/scripts/modules-merkle-tree $@ $(if $(CONFIG_MODULE_INSTALL_STRIP),.ko.stripped,.ko)
-.tmp_module_hashes.c: $(modules:%.o=%.ko) $(objtree)/scripts/modules-merkle-tree FORCE
+.tmp_module_hashes.c: $(if $(CONFIG_MODULE_INSTALL_STRIP),$(modules:%.o=%.ko.stripped),$(modules:%.o=%.ko)) $(objtree)/scripts/modules-merkle-tree $(wildcard include/config/MODULE_INSTALL_STRIP) FORCE
$(call cmd,merkle)
ifdef CONFIG_MODULE_HASHES
@@ -75,6 +79,7 @@ endif
targets += $(modules:%.o=%.ko) $(modules:%.o=%.mod.o) .module-common.o
targets += $(modules:%.o=%.merkle) .tmp_module_hashes.c
+targets += $(modules:%.o=%.ko.stripped)
# Add FORCE to the prerequisites of a target to force it to be always rebuilt.
# ---------------------------------------------------------------------------
diff --git a/scripts/Makefile.modinst b/scripts/Makefile.modinst
index 07380c7233a0..45606f994ad9 100644
--- a/scripts/Makefile.modinst
+++ b/scripts/Makefile.modinst
@@ -68,8 +68,8 @@ __modinst: $(install-y)
ifdef CONFIG_MODULE_HASHES
ifeq ($(KBUILD_EXTMOD),)
-ifdef INSTALL_MOD_STRIP
-$(error CONFIG_MODULE_HASHES and INSTALL_MOD_STRIP are mutually exclusive)
+ifneq ($(INSTALL_MOD_STRIP),$(CONFIG_MODULE_INSTALL_STRIP))
+$(error Inconsistent values for INSTALL_MOD_STRIP between build and installation)
endif
endif
endif
diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux
index f4e38b953b01..4ce849f6253a 100644
--- a/scripts/Makefile.vmlinux
+++ b/scripts/Makefile.vmlinux
@@ -81,6 +81,7 @@ endif
ifdef CONFIG_MODULE_HASHES
vmlinux.unstripped: $(objtree)/scripts/modules-merkle-tree
vmlinux.unstripped: modules.order
+vmlinux.unstripped: $(wildcard include/config/MODULE_INSTALL_STRIP)
endif
# vmlinux
--
2.52.0
^ permalink raw reply related
* [PATCH v4 14/17] lockdown: Make the relationship to MODULE_SIG a dependency
From: Thomas Weißschuh @ 2026-01-13 12:28 UTC (permalink / raw)
To: Nathan Chancellor, Arnd Bergmann, Luis Chamberlain, Petr Pavlu,
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, Nicolas Schier,
Christophe Leroy
Cc: 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, Thomas Weißschuh
In-Reply-To: <20260113-module-hashes-v4-0-0b932db9b56b@weissschuh.net>
The new hash-based module integrity checking will also be able to
satisfy the requirements of lockdown.
Such an alternative is not representable with "select", so use
"depends on" instead.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
security/lockdown/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/security/lockdown/Kconfig b/security/lockdown/Kconfig
index e84ddf484010..155959205b8e 100644
--- a/security/lockdown/Kconfig
+++ b/security/lockdown/Kconfig
@@ -1,7 +1,7 @@
config SECURITY_LOCKDOWN_LSM
bool "Basic module for enforcing kernel lockdown"
depends on SECURITY
- select MODULE_SIG if MODULES
+ depends on !MODULES || MODULE_SIG
help
Build support for an LSM that enforces a coarse kernel lockdown
behaviour.
--
2.52.0
^ permalink raw reply related
* [PATCH v4 13/17] module: Report signature type to users
From: Thomas Weißschuh @ 2026-01-13 12:28 UTC (permalink / raw)
To: Nathan Chancellor, Arnd Bergmann, Luis Chamberlain, Petr Pavlu,
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, Nicolas Schier,
Christophe Leroy
Cc: 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, Thomas Weißschuh
In-Reply-To: <20260113-module-hashes-v4-0-0b932db9b56b@weissschuh.net>
The upcoming CONFIG_MODULE_HASHES will introduce a signature type.
This needs to be handled by callers differently than PKCS7 signatures.
Report the signature type to the caller and let them verify it.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
include/linux/module_signature.h | 2 +-
kernel/module/main.c | 9 +++++++--
kernel/module_signature.c | 14 ++++----------
security/integrity/ima/ima_modsig.c | 8 +++++++-
4 files changed, 19 insertions(+), 14 deletions(-)
diff --git a/include/linux/module_signature.h b/include/linux/module_signature.h
index 186a55effa30..a45ce3b24403 100644
--- a/include/linux/module_signature.h
+++ b/include/linux/module_signature.h
@@ -41,6 +41,6 @@ struct module_signature {
};
int mod_split_sig(const void *buf, size_t *buf_len, bool mangled,
- size_t *sig_len, const u8 **sig, const char *name);
+ enum pkey_id_type *sig_type, size_t *sig_len, const u8 **sig, const char *name);
#endif /* _LINUX_MODULE_SIGNATURE_H */
diff --git a/kernel/module/main.c b/kernel/module/main.c
index d65bc300a78c..2a28a0ece809 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -3348,19 +3348,24 @@ static int module_integrity_check(struct load_info *info, int flags)
{
bool mangled_module = flags & (MODULE_INIT_IGNORE_MODVERSIONS |
MODULE_INIT_IGNORE_VERMAGIC);
+ enum pkey_id_type sig_type;
size_t sig_len;
const u8 *sig;
int err = 0;
if (IS_ENABLED(CONFIG_MODULE_SIG_POLICY)) {
err = mod_split_sig(info->hdr, &info->len, mangled_module,
- &sig_len, &sig, "module");
+ &sig_type, &sig_len, &sig, "module");
if (err)
return err;
}
- if (IS_ENABLED(CONFIG_MODULE_SIG))
+ if (IS_ENABLED(CONFIG_MODULE_SIG) && sig_type == PKEY_ID_PKCS7) {
err = module_sig_check(info, sig, sig_len);
+ } else {
+ pr_err("module: not signed with expected PKCS#7 message\n");
+ err = -ENOPKG;
+ }
if (err)
return err;
diff --git a/kernel/module_signature.c b/kernel/module_signature.c
index b2384a73524c..8e0ac9906c9c 100644
--- a/kernel/module_signature.c
+++ b/kernel/module_signature.c
@@ -19,18 +19,11 @@
* @file_len: Size of the file to which @ms is appended.
* @name: What is being checked. Used for error messages.
*/
-static 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;
- if (ms->id_type != PKEY_ID_PKCS7) {
- pr_err("%s: not signed with expected PKCS#7 message\n",
- name);
- return -ENOPKG;
- }
-
if (ms->algo != 0 ||
ms->hash != 0 ||
ms->signer_len != 0 ||
@@ -38,7 +31,7 @@ static int mod_check_sig(const struct module_signature *ms, size_t file_len,
ms->__pad[0] != 0 ||
ms->__pad[1] != 0 ||
ms->__pad[2] != 0) {
- pr_err("%s: PKCS#7 signature info has unexpected non-zero params\n",
+ pr_err("%s: signature info has unexpected non-zero params\n",
name);
return -EBADMSG;
}
@@ -47,7 +40,7 @@ static int mod_check_sig(const struct module_signature *ms, size_t file_len,
}
int mod_split_sig(const void *buf, size_t *buf_len, bool mangled,
- size_t *sig_len, const u8 **sig, const char *name)
+ enum pkey_id_type *sig_type, size_t *sig_len, const u8 **sig, const char *name)
{
const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
struct module_signature ms;
@@ -74,6 +67,7 @@ int mod_split_sig(const void *buf, size_t *buf_len, bool mangled,
if (ret)
return ret;
+ *sig_type = ms.id_type;
*sig_len = be32_to_cpu(ms.sig_len);
modlen -= *sig_len + sizeof(ms);
*buf_len = modlen;
diff --git a/security/integrity/ima/ima_modsig.c b/security/integrity/ima/ima_modsig.c
index a57342d39b07..a05008324a10 100644
--- a/security/integrity/ima/ima_modsig.c
+++ b/security/integrity/ima/ima_modsig.c
@@ -41,15 +41,21 @@ int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len,
struct modsig **modsig)
{
size_t buf_len_sz = buf_len;
+ enum pkey_id_type sig_type;
struct modsig *hdr;
size_t sig_len;
const u8 *sig;
int rc;
- rc = mod_split_sig(buf, &buf_len_sz, true, &sig_len, &sig, func_tokens[func]);
+ rc = mod_split_sig(buf, &buf_len_sz, true, &sig_type, &sig_len, &sig, func_tokens[func]);
if (rc)
return rc;
+ if (sig_type != PKEY_ID_PKCS7) {
+ pr_err("%s: not signed with expected PKCS#7 message\n", func_tokens[func]);
+ return -ENOPKG;
+ }
+
/* 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)
--
2.52.0
^ permalink raw reply related
* [PATCH v4 12/17] module: Move signature splitting up
From: Thomas Weißschuh @ 2026-01-13 12:28 UTC (permalink / raw)
To: Nathan Chancellor, Arnd Bergmann, Luis Chamberlain, Petr Pavlu,
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, Nicolas Schier,
Christophe Leroy
Cc: 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, Thomas Weißschuh
In-Reply-To: <20260113-module-hashes-v4-0-0b932db9b56b@weissschuh.net>
The signature splitting will also be used by CONFIG_MODULE_HASHES.
Move it up the callchain, so the result can be reused.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
kernel/module/internal.h | 2 +-
kernel/module/main.c | 13 ++++++++++++-
kernel/module/signing.c | 21 +++++++--------------
3 files changed, 20 insertions(+), 16 deletions(-)
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index e053c29a5d08..e2d49122c2a1 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -337,7 +337,7 @@ int module_enforce_rwx_sections(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
void module_mark_ro_after_init(const Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
const char *secstrings);
-int module_sig_check(struct load_info *info, int flags);
+int module_sig_check(struct load_info *info, const u8 *sig, size_t sig_len);
#ifdef CONFIG_DEBUG_KMEMLEAK
void kmemleak_load_module(const struct module *mod, const struct load_info *info);
diff --git a/kernel/module/main.c b/kernel/module/main.c
index c09b25c0166a..d65bc300a78c 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -3346,10 +3346,21 @@ static int early_mod_check(struct load_info *info, int flags)
static int module_integrity_check(struct load_info *info, int flags)
{
+ bool mangled_module = flags & (MODULE_INIT_IGNORE_MODVERSIONS |
+ MODULE_INIT_IGNORE_VERMAGIC);
+ size_t sig_len;
+ const u8 *sig;
int err = 0;
+ if (IS_ENABLED(CONFIG_MODULE_SIG_POLICY)) {
+ err = mod_split_sig(info->hdr, &info->len, mangled_module,
+ &sig_len, &sig, "module");
+ if (err)
+ return err;
+ }
+
if (IS_ENABLED(CONFIG_MODULE_SIG))
- err = module_sig_check(info, flags);
+ err = module_sig_check(info, sig, sig_len);
if (err)
return err;
diff --git a/kernel/module/signing.c b/kernel/module/signing.c
index 8a5f66389116..86164761cac7 100644
--- a/kernel/module/signing.c
+++ b/kernel/module/signing.c
@@ -15,26 +15,19 @@
#include <uapi/linux/module.h>
#include "internal.h"
-int module_sig_check(struct load_info *info, int flags)
+int module_sig_check(struct load_info *info, const u8 *sig, size_t sig_len)
{
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);
- err = mod_split_sig(info->hdr, &info->len, mangled_module, &sig_len, &sig, "module");
+ err = verify_pkcs7_signature(mod, info->len, sig, sig_len,
+ VERIFY_USE_SECONDARY_KEYRING,
+ VERIFYING_MODULE_SIGNATURE,
+ NULL, NULL);
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;
- }
+ info->sig_ok = true;
+ return 0;
}
/*
--
2.52.0
^ permalink raw reply related
* [PATCH v4 08/17] module: Deduplicate signature extraction
From: Thomas Weißschuh @ 2026-01-13 12:28 UTC (permalink / raw)
To: Nathan Chancellor, Arnd Bergmann, Luis Chamberlain, Petr Pavlu,
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, Nicolas Schier,
Christophe Leroy
Cc: 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, Thomas Weißschuh
In-Reply-To: <20260113-module-hashes-v4-0-0b932db9b56b@weissschuh.net>
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;
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]);
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;
--
2.52.0
^ permalink raw reply related
* [PATCH v4 11/17] module: Move lockdown check into generic module loader
From: Thomas Weißschuh @ 2026-01-13 12:28 UTC (permalink / raw)
To: Nathan Chancellor, Arnd Bergmann, Luis Chamberlain, Petr Pavlu,
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, Nicolas Schier,
Christophe Leroy
Cc: 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, Thomas Weißschuh
In-Reply-To: <20260113-module-hashes-v4-0-0b932db9b56b@weissschuh.net>
The lockdown check buried in module_sig_check() will not compose well
with the introduction of hash-based module validation.
Move it into module_integrity_check() which will work better.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
kernel/module/main.c | 6 +++++-
kernel/module/signing.c | 3 +--
2 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 9c570078aa9c..c09b25c0166a 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -3351,7 +3351,11 @@ static int module_integrity_check(struct load_info *info, int flags)
if (IS_ENABLED(CONFIG_MODULE_SIG))
err = module_sig_check(info, flags);
- return err;
+ if (err)
+ return err;
+ if (info->sig_ok)
+ return 0;
+ return security_locked_down(LOCKDOWN_MODULE_SIGNATURE);
}
/*
diff --git a/kernel/module/signing.c b/kernel/module/signing.c
index 66d90784de89..8a5f66389116 100644
--- a/kernel/module/signing.c
+++ b/kernel/module/signing.c
@@ -11,7 +11,6 @@
#include <linux/module_signature.h>
#include <linux/string.h>
#include <linux/verification.h>
-#include <linux/security.h>
#include <crypto/public_key.h>
#include <uapi/linux/module.h>
#include "internal.h"
@@ -68,5 +67,5 @@ int module_sig_check(struct load_info *info, int flags)
return -EKEYREJECTED;
}
- return security_locked_down(LOCKDOWN_MODULE_SIGNATURE);
+ return 0;
}
--
2.52.0
^ permalink raw reply related
* [PATCH v4 04/17] module: Make mod_verify_sig() static
From: Thomas Weißschuh @ 2026-01-13 12:28 UTC (permalink / raw)
To: Nathan Chancellor, Arnd Bergmann, Luis Chamberlain, Petr Pavlu,
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, Nicolas Schier,
Christophe Leroy
Cc: 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, Thomas Weißschuh
In-Reply-To: <20260113-module-hashes-v4-0-0b932db9b56b@weissschuh.net>
It is not used outside of signing.c.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
kernel/module/internal.h | 1 -
kernel/module/signing.c | 2 +-
2 files changed, 1 insertion(+), 2 deletions(-)
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index 618202578b42..e68fbcd60c35 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -119,7 +119,6 @@ struct module_use {
struct module *source, *target;
};
-int mod_verify_sig(const void *mod, struct load_info *info);
int try_to_force_load(struct module *mod, const char *reason);
bool find_symbol(struct find_symbol_arg *fsa);
struct module *find_module_all(const char *name, size_t len, bool even_unformed);
diff --git a/kernel/module/signing.c b/kernel/module/signing.c
index a2ff4242e623..fe3f51ac6199 100644
--- a/kernel/module/signing.c
+++ b/kernel/module/signing.c
@@ -40,7 +40,7 @@ void set_module_sig_enforced(void)
/*
* Verify the signature on a module.
*/
-int mod_verify_sig(const void *mod, struct load_info *info)
+static int mod_verify_sig(const void *mod, struct load_info *info)
{
struct module_signature ms;
size_t sig_len, modlen = info->len;
--
2.52.0
^ permalink raw reply related
* [PATCH v4 10/17] module: Move integrity checks into dedicated function
From: Thomas Weißschuh @ 2026-01-13 12:28 UTC (permalink / raw)
To: Nathan Chancellor, Arnd Bergmann, Luis Chamberlain, Petr Pavlu,
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, Nicolas Schier,
Christophe Leroy
Cc: 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, Thomas Weißschuh
In-Reply-To: <20260113-module-hashes-v4-0-0b932db9b56b@weissschuh.net>
With the addition of hash-based integrity checking, the configuration
matrix is easier to represent in a dedicated function and with explicit
usage of IS_ENABLED().
Drop the now unnecessary stub for module_sig_check().
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
kernel/module/internal.h | 7 -------
kernel/module/main.c | 18 ++++++++++++++----
2 files changed, 14 insertions(+), 11 deletions(-)
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index 037fbb3b7168..e053c29a5d08 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -337,14 +337,7 @@ int module_enforce_rwx_sections(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
void module_mark_ro_after_init(const Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
const char *secstrings);
-#ifdef CONFIG_MODULE_SIG
int module_sig_check(struct load_info *info, int flags);
-#else /* !CONFIG_MODULE_SIG */
-static inline int module_sig_check(struct load_info *info, int flags)
-{
- return 0;
-}
-#endif /* !CONFIG_MODULE_SIG */
#ifdef CONFIG_DEBUG_KMEMLEAK
void kmemleak_load_module(const struct module *mod, const struct load_info *info);
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 4442397a9f92..9c570078aa9c 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -3344,6 +3344,16 @@ static int early_mod_check(struct load_info *info, int flags)
return err;
}
+static int module_integrity_check(struct load_info *info, int flags)
+{
+ int err = 0;
+
+ if (IS_ENABLED(CONFIG_MODULE_SIG))
+ err = module_sig_check(info, flags);
+
+ return err;
+}
+
/*
* Allocate and load the module: note that size of section 0 is always
* zero, and we rely on this for optional sections.
@@ -3357,18 +3367,18 @@ static int load_module(struct load_info *info, const char __user *uargs,
char *after_dashes;
/*
- * Do the signature check (if any) first. All that
- * the signature check needs is info->len, it does
+ * Do the integrity checks (if any) first. All that
+ * they need is info->len, it does
* not need any of the section info. That can be
* set up later. This will minimize the chances
* of a corrupt module causing problems before
- * we even get to the signature check.
+ * we even get to the integrity check.
*
* The check will also adjust info->len by stripping
* off the sig length at the end of the module, making
* checks against info->len more correct.
*/
- err = module_sig_check(info, flags);
+ err = module_integrity_check(info, flags);
if (err)
goto free_copy;
--
2.52.0
^ permalink raw reply related
* [PATCH v4 07/17] kbuild: generate module BTF based on vmlinux.unstripped
From: Thomas Weißschuh @ 2026-01-13 12:28 UTC (permalink / raw)
To: Nathan Chancellor, Arnd Bergmann, Luis Chamberlain, Petr Pavlu,
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, Nicolas Schier,
Christophe Leroy
Cc: 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, Thomas Weißschuh
In-Reply-To: <20260113-module-hashes-v4-0-0b932db9b56b@weissschuh.net>
The upcoming module hashes functionality will build the modules in
between the generation of the BTF data and the final link of vmlinux.
At this point vmlinux is not yet built and therefore can't be used for
module BTF generation. vmlinux.unstripped however is usable and
sufficient for BTF generation.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
scripts/Makefile.modfinal | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal
index adfef1e002a9..930db0524a0a 100644
--- a/scripts/Makefile.modfinal
+++ b/scripts/Makefile.modfinal
@@ -40,11 +40,11 @@ quiet_cmd_ld_ko_o = LD [M] $@
quiet_cmd_btf_ko = BTF [M] $@
cmd_btf_ko = \
- if [ ! -f $(objtree)/vmlinux ]; then \
- printf "Skipping BTF generation for %s due to unavailability of vmlinux\n" $@ 1>&2; \
+ if [ ! -f $(objtree)/vmlinux.unstripped ]; then \
+ printf "Skipping BTF generation for %s due to unavailability of vmlinux.unstripped\n" $@ 1>&2; \
else \
- LLVM_OBJCOPY="$(OBJCOPY)" $(PAHOLE) -J $(PAHOLE_FLAGS) $(MODULE_PAHOLE_FLAGS) --btf_base $(objtree)/vmlinux $@; \
- $(RESOLVE_BTFIDS) -b $(objtree)/vmlinux $@; \
+ LLVM_OBJCOPY="$(OBJCOPY)" $(PAHOLE) -J $(PAHOLE_FLAGS) $(MODULE_PAHOLE_FLAGS) --btf_base $(objtree)/vmlinux.unstripped $@; \
+ $(RESOLVE_BTFIDS) -b $(objtree)/vmlinux.unstripped $@; \
fi;
# Same as newer-prereqs, but allows to exclude specified extra dependencies
--
2.52.0
^ permalink raw reply related
* [PATCH v4 09/17] module: Make module loading policy usable without MODULE_SIG
From: Thomas Weißschuh @ 2026-01-13 12:28 UTC (permalink / raw)
To: Nathan Chancellor, Arnd Bergmann, Luis Chamberlain, Petr Pavlu,
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, Nicolas Schier,
Christophe Leroy
Cc: 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, Thomas Weißschuh
In-Reply-To: <20260113-module-hashes-v4-0-0b932db9b56b@weissschuh.net>
The loading policy functionality will also be used by the hash-based
module validation. Split it out from CONFIG_MODULE_SIG so it is usable
by both.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
include/linux/module.h | 8 ++++----
kernel/module/Kconfig | 5 ++++-
kernel/module/main.c | 26 +++++++++++++++++++++++++-
kernel/module/signing.c | 21 ---------------------
4 files changed, 33 insertions(+), 27 deletions(-)
diff --git a/include/linux/module.h b/include/linux/module.h
index f288ca5cd95b..f9601cba47cd 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -444,7 +444,7 @@ struct module {
const u32 *gpl_crcs;
bool using_gplonly_symbols;
-#ifdef CONFIG_MODULE_SIG
+#ifdef CONFIG_MODULE_SIG_POLICY
/* Signature was verified. */
bool sig_ok;
#endif
@@ -916,7 +916,7 @@ static inline bool retpoline_module_ok(bool has_retpoline)
}
#endif
-#ifdef CONFIG_MODULE_SIG
+#ifdef CONFIG_MODULE_SIG_POLICY
bool is_module_sig_enforced(void);
void set_module_sig_enforced(void);
@@ -925,7 +925,7 @@ static inline bool module_sig_ok(struct module *module)
{
return module->sig_ok;
}
-#else /* !CONFIG_MODULE_SIG */
+#else /* !CONFIG_MODULE_SIG_POLICY */
static inline bool is_module_sig_enforced(void)
{
return false;
@@ -939,7 +939,7 @@ static inline bool module_sig_ok(struct module *module)
{
return true;
}
-#endif /* CONFIG_MODULE_SIG */
+#endif /* CONFIG_MODULE_SIG_POLICY */
#if defined(CONFIG_MODULES) && defined(CONFIG_KALLSYMS)
int module_kallsyms_on_each_symbol(const char *modname,
diff --git a/kernel/module/Kconfig b/kernel/module/Kconfig
index e8bb2c9d917e..db3b61fb3e73 100644
--- a/kernel/module/Kconfig
+++ b/kernel/module/Kconfig
@@ -270,9 +270,12 @@ config MODULE_SIG
debuginfo strip done by some packagers (such as rpmbuild) and
inclusion into an initramfs that wants the module size reduced.
+config MODULE_SIG_POLICY
+ def_bool MODULE_SIG
+
config MODULE_SIG_FORCE
bool "Require modules to be validly signed"
- depends on MODULE_SIG
+ depends on MODULE_SIG_POLICY
help
Reject unsigned modules or signed modules for which we don't have a
key. Without this, such modules will simply taint the kernel.
diff --git a/kernel/module/main.c b/kernel/module/main.c
index a88f95a13e06..4442397a9f92 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -2541,7 +2541,7 @@ static void module_augment_kernel_taints(struct module *mod, struct load_info *i
mod->name);
add_taint_module(mod, TAINT_TEST, LOCKDEP_STILL_OK);
}
-#ifdef CONFIG_MODULE_SIG
+#ifdef CONFIG_MODULE_SIG_POLICY
mod->sig_ok = info->sig_ok;
if (!mod->sig_ok) {
pr_notice_once("%s: module verification failed: signature "
@@ -3921,3 +3921,27 @@ static int module_debugfs_init(void)
}
module_init(module_debugfs_init);
#endif
+
+#ifdef CONFIG_MODULE_SIG_POLICY
+
+#undef MODULE_PARAM_PREFIX
+#define MODULE_PARAM_PREFIX "module."
+
+static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
+module_param(sig_enforce, bool_enable_only, 0644);
+
+/*
+ * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
+ * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
+ */
+bool is_module_sig_enforced(void)
+{
+ return sig_enforce;
+}
+EXPORT_SYMBOL(is_module_sig_enforced);
+
+void set_module_sig_enforced(void)
+{
+ sig_enforce = true;
+}
+#endif
diff --git a/kernel/module/signing.c b/kernel/module/signing.c
index 6d64c0d18d0a..66d90784de89 100644
--- a/kernel/module/signing.c
+++ b/kernel/module/signing.c
@@ -16,27 +16,6 @@
#include <uapi/linux/module.h>
#include "internal.h"
-#undef MODULE_PARAM_PREFIX
-#define MODULE_PARAM_PREFIX "module."
-
-static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
-module_param(sig_enforce, bool_enable_only, 0644);
-
-/*
- * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
- * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
- */
-bool is_module_sig_enforced(void)
-{
- return sig_enforce;
-}
-EXPORT_SYMBOL(is_module_sig_enforced);
-
-void set_module_sig_enforced(void)
-{
- sig_enforce = true;
-}
-
int module_sig_check(struct load_info *info, int flags)
{
int err;
--
2.52.0
^ permalink raw reply related
* [PATCH v4 05/17] module: Switch load_info::len to size_t
From: Thomas Weißschuh @ 2026-01-13 12:28 UTC (permalink / raw)
To: Nathan Chancellor, Arnd Bergmann, Luis Chamberlain, Petr Pavlu,
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, Nicolas Schier,
Christophe Leroy
Cc: 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, Thomas Weißschuh
In-Reply-To: <20260113-module-hashes-v4-0-0b932db9b56b@weissschuh.net>
Switching the types will make some later changes cleaner.
size_t is also the semantically correct type for this field.
As both 'size_t' and 'unsigned int' are always the same size, this
should be risk-free.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
kernel/module/internal.h | 2 +-
kernel/module/main.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index e68fbcd60c35..037fbb3b7168 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -66,7 +66,7 @@ struct load_info {
/* pointer to module in temporary copy, freed at end of load_module() */
struct module *mod;
Elf_Ehdr *hdr;
- unsigned long len;
+ size_t len;
Elf_Shdr *sechdrs;
char *secstrings, *strtab;
unsigned long symoffs, stroffs, init_typeoffs, core_typeoffs;
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 710ee30b3bea..a88f95a13e06 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -1838,7 +1838,7 @@ static int validate_section_offset(const struct load_info *info, Elf_Shdr *shdr)
static int elf_validity_ehdr(const struct load_info *info)
{
if (info->len < sizeof(*(info->hdr))) {
- pr_err("Invalid ELF header len %lu\n", info->len);
+ pr_err("Invalid ELF header len %zu\n", info->len);
return -ENOEXEC;
}
if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0) {
--
2.52.0
^ permalink raw reply related
* [PATCH v4 01/17] module: Only declare set_module_sig_enforced when CONFIG_MODULE_SIG=y
From: Thomas Weißschuh @ 2026-01-13 12:28 UTC (permalink / raw)
To: Nathan Chancellor, Arnd Bergmann, Luis Chamberlain, Petr Pavlu,
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, Nicolas Schier,
Christophe Leroy
Cc: 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, Thomas Weißschuh, Coiby Xu,
kernel test robot
In-Reply-To: <20260113-module-hashes-v4-0-0b932db9b56b@weissschuh.net>
From: Coiby Xu <coxu@redhat.com>
Currently if set_module_sig_enforced is called with CONFIG_MODULE_SIG=n
e.g. [1], it can lead to a linking error,
ld: security/integrity/ima/ima_appraise.o: in function `ima_appraise_measurement':
security/integrity/ima/ima_appraise.c:587:(.text+0xbbb): undefined reference to `set_module_sig_enforced'
This happens because the actual implementation of
set_module_sig_enforced comes from CONFIG_MODULE_SIG but both the
function declaration and the empty stub definition are tied to
CONFIG_MODULES.
So bind set_module_sig_enforced to CONFIG_MODULE_SIG instead. This
allows (future) users to call set_module_sig_enforced directly without
the "if IS_ENABLED(CONFIG_MODULE_SIG)" safeguard.
Note this issue hasn't caused a real problem because all current callers
of set_module_sig_enforced e.g. security/integrity/ima/ima_efi.c
use "if IS_ENABLED(CONFIG_MODULE_SIG)" safeguard.
[1] https://lore.kernel.org/lkml/20250928030358.3873311-1-coxu@redhat.com/
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202510030029.VRKgik99-lkp@intel.com/
Reviewed-by: Aaron Tomlin <atomlin@atomlin.com>
Reviewed-by: Daniel Gomez <da.gomez@samsung.com>
Signed-off-by: Coiby Xu <coxu@redhat.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
---
From modules/modules-next
---
include/linux/module.h | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/include/linux/module.h b/include/linux/module.h
index d80c3ea57472..f288ca5cd95b 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -770,8 +770,6 @@ static inline bool is_livepatch_module(struct module *mod)
#endif
}
-void set_module_sig_enforced(void);
-
void module_for_each_mod(int(*func)(struct module *mod, void *data), void *data);
#else /* !CONFIG_MODULES... */
@@ -866,10 +864,6 @@ static inline bool module_requested_async_probing(struct module *module)
}
-static inline void set_module_sig_enforced(void)
-{
-}
-
/* Dereference module function descriptor */
static inline
void *dereference_module_function_descriptor(struct module *mod, void *ptr)
@@ -925,6 +919,8 @@ static inline bool retpoline_module_ok(bool has_retpoline)
#ifdef CONFIG_MODULE_SIG
bool is_module_sig_enforced(void);
+void set_module_sig_enforced(void);
+
static inline bool module_sig_ok(struct module *module)
{
return module->sig_ok;
@@ -935,6 +931,10 @@ static inline bool is_module_sig_enforced(void)
return false;
}
+static inline void set_module_sig_enforced(void)
+{
+}
+
static inline bool module_sig_ok(struct module *module)
{
return true;
--
2.52.0
^ permalink raw reply related
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