[PATCH 5.15.y] smb: client: fix potential UAF in is_valid_oplock_break()

[PATCH 5.15.y] smb: client: fix potential UAF in is_valid_oplock_break()

[Cliff Liu]

From: Paulo Alcantara <pc@manguebit.com>

[ Upstream commit 69ccf040acddf33a3a85ec0f6b45ef84b0f7ec29 ]

Skip sessions that are being teared down (status == SES_EXITING) to
avoid UAF.

Cc: stable@vger.kernel.org
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
[Minor context change fixed]
Signed-off-by: Cliff Liu <donghua.liu@windriver.com>
Signed-off-by: He Zhe <Zhe.He@windriver.com>
---
Verified the build test.
---
 fs/cifs/misc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index 33328eae03d7..c7e2bf7a0a0d 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -464,6 +464,8 @@ is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
 	spin_lock(&cifs_tcp_ses_lock);
 	list_for_each(tmp, &srv->smb_ses_list) {
 		ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
+		if (cifs_ses_exiting(ses))
+			continue;
 		list_for_each(tmp1, &ses->tcon_list) {
 			tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
 			if (tcon->tid != buf->Tid)
-- 
2.34.1

Re: [PATCH 5.15.y] smb: client: fix potential UAF in is_valid_oplock_break()

[Sasha Levin]

[ Sasha's backport helper bot ]

Hi,

✅ All tests passed successfully. No issues detected.
No action required from the submitter.

The upstream commit SHA1 provided is correct: 69ccf040acddf33a3a85ec0f6b45ef84b0f7ec29

WARNING: Author mismatch between patch and upstream commit:
Backport author: Cliff Liu<donghua.liu@windriver.com>
Commit author: Paulo Alcantara<pc@manguebit.com>

Status in newer kernel trees:
6.14.y | Present (exact SHA1)
6.13.y | Present (exact SHA1)
6.12.y | Present (exact SHA1)
6.6.y | Present (different SHA1: 0a15ba88a32f)
6.1.y | Present (different SHA1: 494c91e1e941)

Note: The patch differs from the upstream commit:
---
1:  69ccf040acddf < -:  ------------- smb: client: fix potential UAF in is_valid_oplock_break()
-:  ------------- > 1:  9bdb460b7ab1a smb: client: fix potential UAF in is_valid_oplock_break()
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-5.15.y       |  Success    |  Success   |