releases/6.6.26/smb-client-fix-potential-uaf-in-cifs_stats_proc_write.patch

   1 From d3da25c5ac84430f89875ca7485a3828150a7e0a Mon Sep 17 00:00:00 2001
   2 From: Paulo Alcantara <pc@manguebit.com>
   3 Date: Tue, 2 Apr 2024 16:33:55 -0300
   4 Subject: smb: client: fix potential UAF in cifs_stats_proc_write()
   5
   6 From: Paulo Alcantara <pc@manguebit.com>
   7
   8 commit d3da25c5ac84430f89875ca7485a3828150a7e0a upstream.
   9
  10 Skip sessions that are being teared down (status == SES_EXITING) to
  11 avoid UAF.
  12
  13 Cc: stable@vger.kernel.org
  14 Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
  15 Signed-off-by: Steve French <stfrench@microsoft.com>
  16 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  17 ---
  18  fs/smb/client/cifs_debug.c |    2 ++
  19  1 file changed, 2 insertions(+)
  20
  21 --- a/fs/smb/client/cifs_debug.c
  22 +++ b/fs/smb/client/cifs_debug.c
  23 @@ -656,6 +656,8 @@ static ssize_t cifs_stats_proc_write(str
  24                         }
  25  #endif /* CONFIG_CIFS_STATS2 */
  26                         list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
  27 +                               if (cifs_ses_exiting(ses))
  28 +                                       continue;
  29                                 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
  30                                         atomic_set(&tcon->num_smbs_sent, 0);
  31                                         spin_lock(&tcon->stat_lock);