queue-6.6/smb-client-fix-potential-uaf-in-cifs_dump_full_key.patch

   1 From 58acd1f497162e7d282077f816faa519487be045 Mon Sep 17 00:00:00 2001
   2 From: Paulo Alcantara <pc@manguebit.com>
   3 Date: Tue, 2 Apr 2024 16:33:54 -0300
   4 Subject: smb: client: fix potential UAF in cifs_dump_full_key()
   5
   6 From: Paulo Alcantara <pc@manguebit.com>
   7
   8 commit 58acd1f497162e7d282077f816faa519487be045 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/ioctl.c |    6 +++++-
  19  1 file changed, 5 insertions(+), 1 deletion(-)
  20
  21 --- a/fs/smb/client/ioctl.c
  22 +++ b/fs/smb/client/ioctl.c
  23 @@ -246,7 +246,9 @@ static int cifs_dump_full_key(struct cif
  24                 spin_lock(&cifs_tcp_ses_lock);
  25                 list_for_each_entry(server_it, &cifs_tcp_ses_list, tcp_ses_list) {
  26                         list_for_each_entry(ses_it, &server_it->smb_ses_list, smb_ses_list) {
  27 -                               if (ses_it->Suid == out.session_id) {
  28 +                               spin_lock(&ses_it->ses_lock);
  29 +                               if (ses_it->ses_status != SES_EXITING &&
  30 +                                   ses_it->Suid == out.session_id) {
  31                                         ses = ses_it;
  32                                         /*
  33                                          * since we are using the session outside the crit
  34 @@ -254,9 +256,11 @@ static int cifs_dump_full_key(struct cif
  35                                          * so increment its refcount
  36                                          */
  37                                         cifs_smb_ses_inc_refcount(ses);
  38 +                                       spin_unlock(&ses_it->ses_lock);
  39                                         found = true;
  40                                         goto search_end;
  41                                 }
  42 +                               spin_unlock(&ses_it->ses_lock);
  43                         }
  44                 }
  45  search_end: