smb3: fix possible access to uninitialized pointer to DACL
dacl_ptr can be null so we must check for it (ie if dacloffset is
set) everywhere dacl_ptr is
used in build_sec_desc - and we were missing one check
Addresses-Coverity: 1475598 ("Explicit null dereference")
--
Thanks,
Steve
From ec06cb04376e5abc927a9b85dd768ce8728965bb Mon Sep 17 00:00:00 2001
From: Steve French <stfrench@xxxxxxxxxxxxx>
Date: Tue, 22 Jun 2021 17:54:50 -0500
Subject: [PATCH] smb3: fix possible access to uninitialized pointer to DACL
dacl_ptr can be null so we must check for it everywhere it is
used in build_sec_desc.
Addresses-Coverity: 1475598 ("Explicit null dereference")
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
---
fs/cifs/cifsacl.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index 784407f9280f..25a8139336fa 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -1308,7 +1308,7 @@ static int build_sec_desc(struct cifs_ntsd *pntsd, struct cifs_ntsd *pnntsd,
ndacl_ptr = (struct cifs_acl *)((char *)pnntsd + ndacloffset);
ndacl_ptr->revision =
dacloffset ? dacl_ptr->revision : cpu_to_le16(ACL_REVISION);
- ndacl_ptr->num_aces = dacl_ptr->num_aces;
+ ndacl_ptr->num_aces = dacloffset ? dacl_ptr->num_aces : 0;
if (uid_valid(uid)) { /* chown */
uid_t id;
--
2.30.2
