From: Paulo Alcantara <pc@manguebit.com>
Date: Tue, 2 Apr 2024 19:34:00 +0000 (-0300)
Subject: smb: client: fix potential UAF in is_valid_oplock_break()
X-Git-Tag: v6.9-rc3~7^2~2
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=69ccf040acddf33a3a85ec0f6b45ef84b0f7ec29;p=linux-block.git

smb: client: fix potential UAF in is_valid_oplock_break()

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>
---

diff --git a/fs/smb/client/misc.c b/fs/smb/client/misc.c
index 1ea22b3955a2..33ac4f8f5050 100644
--- a/fs/smb/client/misc.c
+++ b/fs/smb/client/misc.c
@@ -481,6 +481,8 @@ is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
 	/* look up tcon based on tid & uid */
 	spin_lock(&cifs_tcp_ses_lock);
 	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
+		if (cifs_ses_exiting(ses))
+			continue;
 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
 			if (tcon->tid != buf->Tid)
 				continue;