[lvc-project] [PATCH 5.10] smb: client: fix potential UAF in smb2_is_valid_lease_break()

[Viktoriya Danchenko]

From: Paulo Alcantara <pc at manguebit.com>

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

Cc: stable at vger.kernel.org
Signed-off-by: Paulo Alcantara (Red Hat) <pc at manguebit.com>
Signed-off-by: Steve French <stfrench at microsoft.com>
Signed-off-by: Karina Yankevich <k.yankevich at omp.ru>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Viktoriya Danchenko <v.danchenko at omp.ru>
---
Backport fix for CVE-2024-35864
---
 fs/cifs/smb2misc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
index c0b80ba8875a..d4be0735a25d 100644
--- a/fs/cifs/smb2misc.c
+++ b/fs/cifs/smb2misc.c
@@ -619,6 +619,8 @@ smb2_is_valid_lease_break(char *buffer)
 		list_for_each(tmp1, &server->smb_ses_list) {
 			ses = list_entry(tmp1, struct cifs_ses, smb_ses_list);
 
+			if (cifs_ses_exiting(ses))
+				continue;
 			list_for_each(tmp2, &ses->tcon_list) {
 				tcon = list_entry(tmp2, struct cifs_tcon,
 						  tcon_list);
-- 
2.43.0