eCryptfs: ecryptfs_setattr() bugfix

PATCH New Michael Halcrow 1 participant 1 message Jul 16, 2007 Ecrypt file system

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Michael Halcrow

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2007-07-16 04:16 UTC #0 lore raw

PATCH 1/1 eCryptfs: ecryptfs_setattr() bugfix

There is another bug recently introduced into the ecryptfs_setattr() function in 2.6.22. eCryptfs will attempt to treat special files like regular eCryptfs files on chmod, chown, and so forth. This leads to a NULL pointer dereference. This patch validates that the file is a regular file before proceeding with operations related to the inode's crypt_stat.

Thanks to Ryusuke Konishi for finding this bug and suggesting the fix.

Signed-off-by Michael Halcrow <[email protected]>

---
 fs/ecryptfs/inode.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

fs/ecryptfs/inode.c +3 -2

index 83e94fe..9c6877c 100644
@@ -902,8 +902,9 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
 	mutex_lock(&crypt_stat->cs_mutex);
 	if (S_ISDIR(dentry->d_inode->i_mode))
 		crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
-	else if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
-		 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID)) {
+	else if (S_ISREG(dentry->d_inode->i_mode)
+		 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
+		     || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
 		struct vfsmount *lower_mnt;
 		struct file *lower_file = NULL;
 		struct ecryptfs_mount_crypt_stat *mount_crypt_stat;

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1.5.2.1