queue-3.18/udf-fix-crash-on-io-error-during-truncate.patch

   1 From d3ca4651d05c0ff7259d087d8c949bcf3e14fb46 Mon Sep 17 00:00:00 2001
   2 From: Jan Kara <jack@suse.cz>
   3 Date: Mon, 11 Mar 2019 15:04:18 +0100
   4 Subject: udf: Fix crash on IO error during truncate
   5
   6 From: Jan Kara <jack@suse.cz>
   7
   8 commit d3ca4651d05c0ff7259d087d8c949bcf3e14fb46 upstream.
   9
  10 When truncate(2) hits IO error when reading indirect extent block the
  11 code just bugs with:
  12
  13 kernel BUG at linux-4.15.0/fs/udf/truncate.c:249!
  14 ...
  15
  16 Fix the problem by bailing out cleanly in case of IO error.
  17
  18 CC: stable@vger.kernel.org
  19 Reported-by: jean-luc malet <jeanluc.malet@gmail.com>
  20 Signed-off-by: Jan Kara <jack@suse.cz>
  21 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  22
  23 ---
  24  fs/udf/truncate.c |    3 +++
  25  1 file changed, 3 insertions(+)
  26
  27 --- a/fs/udf/truncate.c
  28 +++ b/fs/udf/truncate.c
  29 @@ -261,6 +261,9 @@ void udf_truncate_extents(struct inode *
  30                         epos.block = eloc;
  31                         epos.bh = udf_tread(sb,
  32                                         udf_get_lb_pblock(sb, &eloc, 0));
  33 +                       /* Error reading indirect block? */
  34 +                       if (!epos.bh)
  35 +                               return;
  36                         if (elen)
  37                                 indirect_ext_len =
  38                                         (elen + sb->s_blocksize - 1) >>