[PATCH 22/59] CRED: Wrap task credential accesses in the eCryptFS filesystem

David Howells
2008-08-27T13:50:00Z

Cc: Mike Halcrow <mhalcrow@us.ibm.com>
Cc: Phillip Hellewell <phillip@hellewell.homeip.net>
Cc: ecryptfs-devel@lists.sourceforge.net
---

fs/ecryptfs/messaging.c | 18 ++++++++++--------
fs/ecryptfs/miscdev.c | 20 ++++++++++++--------
2 files changed, 22 insertions(+), 16 deletions(-)

diff --git a/fs/ecryptfs/messaging.c b/fs/ecryptfs/messaging.c
index 1b5c200..92bf606 100644
--- a/fs/ecryptfs/messaging.c
+++ b/fs/ecryptfs/messaging.c
@@ -377,6 +377,7 @@ int ecryptfs_process_response(struct ecryptfs_message *msg, uid_t euid,
size_t msg_size;
struct nsproxy *nsproxy;
struct user_namespace *current_user_ns;
+ uid_t ctx_euid;
int rc;

if (msg->index >= ecryptfs_message_buf_len) {
@@ -401,8 +402,8 @@ int ecryptfs_process_response(struct ecryptfs_message *msg, uid_t euid,
goto wake_up;
}
current_user_ns = nsproxy->user_ns;
- rc = ecryptfs_find_daemon_by_euid(&daemon, msg_ctx->task->euid,
- current_user_ns);
+ ctx_euid = task_euid(msg_ctx->task);
+ rc = ecryptfs_find_daemon_by_euid(&daemon, ctx_euid, current_user_ns);
rcu_read_unlock();
mutex_unlock(&ecryptfs_daemon_hash_mux);
if (rc) {
@@ -410,14 +411,14 @@ int ecryptfs_process_response(struct ecryptfs_message *msg, uid_t euid,
printk(KERN_WARNING "%s: User [%d] received a "
"message response from process [0x%p] but does "
"not have a registered daemon\n", __func__,
- msg_ctx->task->euid, pid);
+ ctx_euid, pid);
goto wake_up;
}
- if (msg_ctx->task->euid != euid) {
+ if (ctx_euid != euid) {
rc = -EBADMSG;
printk(KERN_WARNING "%s: Received message from user "
"[%d]; expected message from user [%d]\n", __func__,
- euid, msg_ctx->task->euid);
+ euid, ctx_euid);
goto unlock;
}
if (current_user_ns != user_ns) {
@@ -431,7 +432,7 @@ int ecryptfs_process_response(struct ecryptfs_message *msg, uid_t euid,
rc = -EBADMSG;
printk(KERN_ERR "%s: User [%d] sent a message response "
"from an unrecognized process [0x%p]\n",
- __func__, msg_ctx->task->euid, pid);
+ __func__, ctx_euid, pid);
goto unlock;
}
if (msg_ctx->state != ECRYPTFS_MSG_CTX_STATE_PENDING) {
@@ -482,14 +483,15 @@ ecryptfs_send_message_locked(unsigned int transport, char *data, int data_len,
u8 msg_type, struct ecryptfs_msg_ctx **msg_ctx)
{
struct ecryptfs_daemon *daemon;
+ uid_t euid = current_euid();
int rc;

- rc = ecryptfs_find_daemon_by_euid(&daemon, current->euid,
+ rc = ecryptfs_find_daemon_by_euid(&daemon, euid,
current->nsproxy->user_ns);
if (rc || !daemon) {
rc = -ENOTCONN;
printk(KERN_ERR "%s: User [%d] does not have a daemon "
- "registered\n", __func__, current->euid);
+ "registered\n", __func__, euid);
goto out;
}
mutex_lock(&ecryptfs_msg_ctx_lists_mux);
diff --git a/fs/ecryptfs/miscdev.c b/fs/ecryptfs/miscdev.c
index b484792..047ac60 100644
--- a/fs/ecryptfs/miscdev.c
+++ b/fs/ecryptfs/miscdev.c
@@ -42,11 +42,12 @@ ecryptfs_miscdev_poll(struct file *file, poll_table *pt)
{
struct ecryptfs_daemon *daemon;
unsigned int mask = 0;
+ uid_t euid = current_euid();
int rc;

mutex_lock(&ecryptfs_daemon_hash_mux);
/* TODO: Just use file->private_data? */
- rc = ecryptfs_find_daemon_by_euid(&daemon, current->euid,
+ rc = ecryptfs_find_daemon_by_euid(&daemon, euid,
current->nsproxy->user_ns);
BUG_ON(rc || !daemon);
mutex_lock(&daemon->mux);
@@ -83,6 +84,7 @@ static int
ecryptfs_miscdev_open(struct inode *inode, struct file *file)
{
struct ecryptfs_daemon *daemon = NULL;
+ uid_t euid = current_euid();
int rc;

mutex_lock(&ecryptfs_daemon_hash_mux);
@@ -93,10 +95,10 @@ ecryptfs_miscdev_open(struct inode *inode, struct file *file)
"count; rc = [%d]\n", __func__, rc);
goto out_unlock_daemon_list;
}
- rc = ecryptfs_find_daemon_by_euid(&daemon, current->euid,
+ rc = ecryptfs_find_daemon_by_euid(&daemon, euid,
current->nsproxy->user_ns);
if (rc || !daemon) {
- rc = ecryptfs_spawn_daemon(&daemon, current->euid,
+ rc = ecryptfs_spawn_daemon(&daemon, euid,
current->nsproxy->user_ns,
task_pid(current));
if (rc) {
@@ -147,10 +149,11 @@ static int
ecryptfs_miscdev_release(struct inode *inode, struct file *file)
{
struct ecryptfs_daemon *daemon = NULL;
+ uid_t euid = current_euid();
int rc;

mutex_lock(&ecryptfs_daemon_hash_mux);
- rc = ecryptfs_find_daemon_by_euid(&daemon, current->euid,
+ rc = ecryptfs_find_daemon_by_euid(&daemon, euid,
current->nsproxy->user_ns);
BUG_ON(rc || !daemon);
mutex_lock(&daemon->mux);
@@ -246,11 +249,12 @@ ecryptfs_miscdev_read(struct file *file, char __user *buf, size_t count,
char packet_length[3];
size_t i;
size_t total_length;
+ uid_t euid = current_euid();
int rc;

mutex_lock(&ecryptfs_daemon_hash_mux);
/* TODO: Just use file->private_data? */
- rc = ecryptfs_find_daemon_by_euid(&daemon, current->euid,
+ rc = ecryptfs_find_daemon_by_euid(&daemon, euid,
current->nsproxy->user_ns);
BUG_ON(rc || !daemon);
mutex_lock(&daemon->mux);
@@ -290,7 +294,7 @@ check_list:
* message from the queue; try again */
goto check_list;
}
- BUG_ON(current->euid != daemon->euid);
+ BUG_ON(euid != daemon->euid);
BUG_ON(current->nsproxy->user_ns != daemon->user_ns);
BUG_ON(task_pid(current) != daemon->pid);
msg_ctx = list_first_entry(&daemon->msg_ctx_out_queue,
@@ -414,6 +418,7 @@ ecryptfs_miscdev_write(struct file *file, const char __user *buf,
size_t packet_size, packet_size_length, i;
ssize_t sz = 0;
char *data;
+ uid_t euid = current_euid();
int rc;

if (count == 0)
@@ -463,8 +468,7 @@ ecryptfs_miscdev_write(struct file *file, const char __user *buf,
goto out_free;
}
rc = ecryptfs_miscdev_response(&data[i], packet_size,
- current->euid,
- current->nsproxy->user_ns,
+ euid, current->nsproxy->user_ns,
task_pid(current), seq);
if (rc)
printk(KERN_WARNING "%s: Failed to deliver miscdev "