This is a note to let you know that I've just added the patch titled
cifs: prevent NULL deref in cifs_compose_mount_options()
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
cifs-prevent-null-deref-in-cifs_compose_mount_option.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 11184dd129c93ab884d5e15dfb3afbcd2eca223d
Author: Paulo Alcantara <pc@xxxxxx>
Date: Fri Jul 2 11:50:54 2021 -0300
cifs: prevent NULL deref in cifs_compose_mount_options()
[ Upstream commit 03313d1c3a2f086bb60920607ab79ac8f8578306 ]
The optional @ref parameter might contain an NULL node_name, so
prevent dereferencing it in cifs_compose_mount_options().
Addresses-Coverity: 1476408 ("Explicit null dereferenced")
Signed-off-by: Paulo Alcantara (SUSE) <pc@xxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c
index cc3ada12848d..42125601ebb1 100644
--- a/fs/cifs/cifs_dfs_ref.c
+++ b/fs/cifs/cifs_dfs_ref.c
@@ -151,6 +151,9 @@ char *cifs_compose_mount_options(const char *sb_mountdata,
return ERR_PTR(-EINVAL);
if (ref) {
+ if (WARN_ON_ONCE(!ref->node_name || ref->path_consumed < 0))
+ return ERR_PTR(-EINVAL);
+
if (strlen(fullpath) - ref->path_consumed) {
prepath = fullpath + ref->path_consumed;
/* skip initial delimiter */
