queue-6.6/ksmbd-fix-slab-out-of-bounds-in-smb2_allocate_rsp_buf.patch

   1 From c119f4ede3fa90a9463f50831761c28f989bfb20 Mon Sep 17 00:00:00 2001
   2 From: Namjae Jeon <linkinjeon@kernel.org>
   3 Date: Thu, 11 Apr 2024 23:02:15 +0900
   4 Subject: ksmbd: fix slab-out-of-bounds in smb2_allocate_rsp_buf
   5
   6 From: Namjae Jeon <linkinjeon@kernel.org>
   7
   8 commit c119f4ede3fa90a9463f50831761c28f989bfb20 upstream.
   9
  10 If ->ProtocolId is SMB2_TRANSFORM_PROTO_NUM, smb2 request size
  11 validation could be skipped. if request size is smaller than
  12 sizeof(struct smb2_query_info_req), slab-out-of-bounds read can happen in
  13 smb2_allocate_rsp_buf(). This patch allocate response buffer after
  14 decrypting transform request. smb3_decrypt_req() will validate transform
  15 request size and avoid slab-out-of-bound in smb2_allocate_rsp_buf().
  16
  17 Reported-by: Norbert Szetei <norbert@doyensec.com>
  18 Cc: stable@vger.kernel.org
  19 Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
  20 Signed-off-by: Steve French <stfrench@microsoft.com>
  21 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  22 ---
  23  fs/smb/server/server.c |   13 +++++--------
  24  1 file changed, 5 insertions(+), 8 deletions(-)
  25
  26 --- a/fs/smb/server/server.c
  27 +++ b/fs/smb/server/server.c
  28 @@ -167,20 +167,17 @@ static void __handle_ksmbd_work(struct k
  29         int rc;
  30         bool is_chained = false;
  31
  32 -       if (conn->ops->allocate_rsp_buf(work))
  33 -               return;
  34 -
  35         if (conn->ops->is_transform_hdr &&
  36             conn->ops->is_transform_hdr(work->request_buf)) {
  37                 rc = conn->ops->decrypt_req(work);
  38 -               if (rc < 0) {
  39 -                       conn->ops->set_rsp_status(work, STATUS_DATA_ERROR);
  40 -                       goto send;
  41 -               }
  42 -
  43 +               if (rc < 0)
  44 +                       return;
  45                 work->encrypted = true;
  46         }
  47
  48 +       if (conn->ops->allocate_rsp_buf(work))
  49 +               return;
  50 +
  51         rc = conn->ops->init_rsp_hdr(work);
  52         if (rc) {
  53                 /* either uid or tid is not correct */