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@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Paulo Alcantara 2021-07-02 11:50:54 -03:00 committed by Greg Kroah-Hartman
parent faa3e7da48
commit e58c162789

View File

@ -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 */