queue-4.19/block-do-not-leak-memory-in-bio_copy_user_iov.patch

   1 From a3761c3c91209b58b6f33bf69dd8bb8ec0c9d925 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= <jglisse@redhat.com>
   3 Date: Wed, 10 Apr 2019 16:27:51 -0400
   4 Subject: block: do not leak memory in bio_copy_user_iov()
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 From: Jérôme Glisse <jglisse@redhat.com>
  10
  11 commit a3761c3c91209b58b6f33bf69dd8bb8ec0c9d925 upstream.
  12
  13 When bio_add_pc_page() fails in bio_copy_user_iov() we should free
  14 the page we just allocated otherwise we are leaking it.
  15
  16 Cc: linux-block@vger.kernel.org
  17 Cc: Linus Torvalds <torvalds@linux-foundation.org>
  18 Cc: stable@vger.kernel.org
  19 Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
  20 Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
  21 Signed-off-by: Jens Axboe <axboe@kernel.dk>
  22 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  23
  24 ---
  25  block/bio.c |    5 ++++-
  26  1 file changed, 4 insertions(+), 1 deletion(-)
  27
  28 --- a/block/bio.c
  29 +++ b/block/bio.c
  30 @@ -1240,8 +1240,11 @@ struct bio *bio_copy_user_iov(struct req
  31                         }
  32                 }
  33
  34 -               if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes)
  35 +               if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes) {
  36 +                       if (!map_data)
  37 +                               __free_page(page);
  38                         break;
  39 +               }
  40
  41                 len -= bytes;
  42                 offset = 0;