releases/4.14.44/ext2-fix-a-block-leak.patch

   1 From 5aa1437d2d9a068c0334bd7c9dafa8ec4f97f13b Mon Sep 17 00:00:00 2001
   2 From: Al Viro <viro@zeniv.linux.org.uk>
   3 Date: Thu, 17 May 2018 17:18:30 -0400
   4 Subject: ext2: fix a block leak
   5
   6 From: Al Viro <viro@zeniv.linux.org.uk>
   7
   8 commit 5aa1437d2d9a068c0334bd7c9dafa8ec4f97f13b upstream.
   9
  10 open file, unlink it, then use ioctl(2) to make it immutable or
  11 append only.  Now close it and watch the blocks *not* freed...
  12
  13 Immutable/append-only checks belong in ->setattr().
  14 Note: the bug is old and backport to anything prior to 737f2e93b972
  15 ("ext2: convert to use the new truncate convention") will need
  16 these checks lifted into ext2_setattr().
  17
  18 Cc: stable@kernel.org
  19 Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
  20 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  21
  22 ---
  23  fs/ext2/inode.c |   10 ----------
  24  1 file changed, 10 deletions(-)
  25
  26 --- a/fs/ext2/inode.c
  27 +++ b/fs/ext2/inode.c
  28 @@ -1261,21 +1261,11 @@ do_indirects:
  29
  30  static void ext2_truncate_blocks(struct inode *inode, loff_t offset)
  31  {
  32 -       /*
  33 -        * XXX: it seems like a bug here that we don't allow
  34 -        * IS_APPEND inode to have blocks-past-i_size trimmed off.
  35 -        * review and fix this.
  36 -        *
  37 -        * Also would be nice to be able to handle IO errors and such,
  38 -        * but that's probably too much to ask.
  39 -        */
  40         if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
  41             S_ISLNK(inode->i_mode)))
  42                 return;
  43         if (ext2_inode_is_fast_symlink(inode))
  44                 return;
  45 -       if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
  46 -               return;
  47
  48         dax_sem_down_write(EXT2_I(inode));
  49         __ext2_truncate_blocks(inode, offset);