summary refs log tree commit diff
path: root/fs/ecryptfs/crypto.c
diff options
context:
space:
mode:
authorTyler Hicks <tyhicks@linux.vnet.ibm.com>2009-03-20 02:23:57 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2009-03-22 11:20:43 -0700
commit2aac0cf88681bfa092f731553bc7fbd23516be73 (patch)
treeb723cbe9c67b0cafa9081690d03b4ecec038d9f6 /fs/ecryptfs/crypto.c
parent8faece5f906725c10e7a1f6caf84452abadbdc7b (diff)
downloadlinux-2aac0cf88681bfa092f731553bc7fbd23516be73.tar.gz
eCryptfs: NULL crypt_stat dereference during lookup
If ecryptfs_encrypted_view or ecryptfs_xattr_metadata were being
specified as mount options, a NULL pointer dereference of crypt_stat
was possible during lookup.

This patch moves the crypt_stat assignment into
ecryptfs_lookup_and_interpose_lower(), ensuring that crypt_stat
will not be NULL before we attempt to dereference it.

Thanks to Dan Carpenter and his static analysis tool, smatch, for
finding this bug.

Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Acked-by: Dustin Kirkland <kirkland@canonical.com>
Cc: Dan Carpenter <error27@gmail.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/ecryptfs/crypto.c')
-rw-r--r--fs/ecryptfs/crypto.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index 75bee99de0f6..8b65f289ee00 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -2221,17 +2221,19 @@ int ecryptfs_decode_and_decrypt_filename(char **plaintext_name,
 					 struct dentry *ecryptfs_dir_dentry,
 					 const char *name, size_t name_size)
 {
+	struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
+		&ecryptfs_superblock_to_private(
+			ecryptfs_dir_dentry->d_sb)->mount_crypt_stat;
 	char *decoded_name;
 	size_t decoded_name_size;
 	size_t packet_size;
 	int rc = 0;
 
-	if ((name_size > ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE)
+	if ((mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
+	    && !(mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
+	    && (name_size > ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE)
 	    && (strncmp(name, ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX,
 			ECRYPTFS_FNEK_ENCRYPTED_FILENAME_PREFIX_SIZE) == 0)) {
-		struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
-			&ecryptfs_superblock_to_private(
-				ecryptfs_dir_dentry->d_sb)->mount_crypt_stat;
 		const char *orig_name = name;
 		size_t orig_name_size = name_size;