[PATCH AUTOSEL 5.15 12/28] cifs: do not use uninitialized data in the owner/group sid

Sasha Levin
2022-02-23T02:31:29Z

From: Ronnie Sahlberg <lsahlber@redhat.com>

[ Upstream commit 26d3dadebbcbddfaf1d9caad42527a28a0ed28d8 ]

When idsfromsid is used we create a special SID for owner/group.
This structure must be initialized or else the first 5 bytes
of the Authority field of the SID will contain uninitialized data
and thus not be a valid SID.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/cifs/cifsacl.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index ee3aab3dd4ac6..5df21d63dd04e 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -1297,7 +1297,7 @@ static int build_sec_desc(struct cifs_ntsd *pntsd, struct cifs_ntsd *pnntsd,

if (uid_valid(uid)) { /* chown */
uid_t id;
- nowner_sid_ptr = kmalloc(sizeof(struct cifs_sid),
+ nowner_sid_ptr = kzalloc(sizeof(struct cifs_sid),
GFP_KERNEL);
if (!nowner_sid_ptr) {
rc = -ENOMEM;
@@ -1326,7 +1326,7 @@ static int build_sec_desc(struct cifs_ntsd *pntsd, struct cifs_ntsd *pnntsd,
}
if (gid_valid(gid)) { /* chgrp */
gid_t id;
- ngroup_sid_ptr = kmalloc(sizeof(struct cifs_sid),
+ ngroup_sid_ptr = kzalloc(sizeof(struct cifs_sid),
GFP_KERNEL);
if (!ngroup_sid_ptr) {
rc = -ENOMEM;
--
2.34.1