linux-stable.git/fs/ext4, branch v3.12.72

ext4: return EROFS if device is r/o and journal replay is needed

2017-03-13T20:40:31+00:00

commit 4753d8a24d4588657bc0a4cd66d4e282dff15c8c upstream.

If the file system requires journal recovery, and the device is
read-ony, return EROFS to the mount system call.  This allows xfstests
generic/050 to pass.

Signed-off-by: Theodore Ts'o 
Signed-off-by: Jiri Slaby

ext4: preserve the needs_recovery flag when the journal is aborted

2017-03-13T20:40:30+00:00

commit 97abd7d4b5d9c48ec15c425485f054e1c15e591b upstream.

If the journal is aborted, the needs_recovery feature flag should not
be removed.  Otherwise, it's the journal might not get replayed and
this could lead to more data getting lost.

Signed-off-by: Theodore Ts'o 
Signed-off-by: Jiri Slaby

ext4: trim allocation requests to group size

2017-03-13T20:40:29+00:00

commit cd648b8a8fd5071d232242d5ee7ee3c0815776af upstream.

If filesystem groups are artifically small (using parameter -g to
mkfs.ext4), ext4_mb_normalize_request() can result in a request that is
larger than a block group. Trim the request size to not confuse
allocation code.

Reported-by: "Kirill A. Shutemov" 
Signed-off-by: Jan Kara 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Jiri Slaby

ext4: fix fencepost in s_first_meta_bg validation

2017-03-03T10:30:48+00:00

commit 2ba3e6e8afc9b6188b471f27cf2b5e3cf34e7af2 upstream.

It is OK for s_first_meta_bg to be equal to the number of block group
descriptor blocks.  (It rarely happens, but it shouldn't cause any
problems.)

https://bugzilla.kernel.org/show_bug.cgi?id=194567

Fixes: 3a4b77cd47bb837b8557595ec7425f281f2ca1fe
Signed-off-by: Theodore Ts'o 
Signed-off-by: Jiri Slaby

ext4: validate s_first_meta_bg at mount time

2017-03-03T10:29:32+00:00

commit 3a4b77cd47bb837b8557595ec7425f281f2ca1fe upstream.

Ralf Spenneberg reported that he hit a kernel crash when mounting a
modified ext4 image. And it turns out that kernel crashed when
calculating fs overhead (ext4_calculate_overhead()), this is because
the image has very large s_first_meta_bg (debug code shows it's
842150400), and ext4 overruns the memory in count_overhead() when
setting bitmap buffer, which is PAGE_SIZE.

ext4_calculate_overhead():
  buf = get_zeroed_page(GFP_NOFS);  <=== PAGE_SIZE buffer
  blks = count_overhead(sb, i, buf);

count_overhead():
  for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) { <=== j = 842150400
          ext4_set_bit(EXT4_B2C(sbi, s++), buf);   <=== buffer overrun
          count++;
  }

This can be reproduced easily for me by this script:

  #!/bin/bash
  rm -f fs.img
  mkdir -p /mnt/ext4
  fallocate -l 16M fs.img
  mke2fs -t ext4 -O bigalloc,meta_bg,^resize_inode -F fs.img
  debugfs -w -R "ssv first_meta_bg 842150400" fs.img
  mount -o loop fs.img /mnt/ext4

Fix it by validating s_first_meta_bg first at mount time, and
refusing to mount if its value exceeds the largest possible meta_bg
number.

[js] use EXT4_HAS_INCOMPAT_FEATURE instead of new
     ext4_has_feature_meta_bg

Reported-by: Ralf Spenneberg 
Signed-off-by: Eryu Guan 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Andreas Dilger 
Signed-off-by: Jiri Slaby

posix_acl: Clear SGID bit when setting file permissions

2017-01-27T10:15:59+00:00

commit 073931017b49d9458aa351605b43a7e34598caef upstream.

When file permissions are modified via chmod(2) and the user is not in
the owning group or capable of CAP_FSETID, the setgid bit is cleared in
inode_change_ok().  Setting a POSIX ACL via setxattr(2) sets the file
permissions as well as the new ACL, but doesn't clear the setgid bit in
a similar way; this allows to bypass the check in chmod(2).  Fix that.

Reviewed-by: Christoph Hellwig 
Reviewed-by: Jeff Layton 
Signed-off-by: Jan Kara 
Signed-off-by: Andreas Gruenbacher 
Signed-off-by: Jiri Slaby

ext4: return -ENOMEM instead of success

2017-01-26T16:22:36+00:00

commit 578620f451f836389424833f1454eeeb2ffc9e9f upstream.

We should set the error code if kzalloc() fails.

Fixes: 67cf5b09a46f ("ext4: add the basic function for inline data support")
Signed-off-by: Dan Carpenter 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Jiri Slaby

ext4: reject inodes with negative size

2017-01-26T16:22:35+00:00

commit 7e6e1ef48fc02f3ac5d0edecbb0c6087cd758d58 upstream.

Don't load an inode with a negative size; this causes integer overflow
problems in the VFS.

[ Added EXT4_ERROR_INODE() to mark file system as corrupted. -TYT]

js: use EIO for 3.12 instead of EFSCORRUPTED.

Fixes: a48380f769df (ext4: rename i_dir_acl to i_size_high)
Signed-off-by: Darrick J. Wong 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Jiri Slaby

ext4: add sanity checking to count_overhead()

2017-01-26T16:22:34+00:00

commit c48ae41bafe31e9a66d8be2ced4e42a6b57fa814 upstream.

The commit "ext4: sanity check the block and cluster size at mount
time" should prevent any problems, but in case the superblock is
modified while the file system is mounted, add an extra safety check
to make sure we won't overrun the allocated buffer.

Signed-off-by: Theodore Ts'o 
Signed-off-by: Jiri Slaby

ext4: fix in-superblock mount options processing

2017-01-26T16:22:34+00:00

commit 5aee0f8a3f42c94c5012f1673420aee96315925a upstream.

Fix a large number of problems with how we handle mount options in the
superblock.  For one, if the string in the superblock is long enough
that it is not null terminated, we could run off the end of the string
and try to interpret superblocks fields as characters.  It's unlikely
this will cause a security problem, but it could result in an invalid
parse.  Also, parse_options is destructive to the string, so in some
cases if there is a comma-separated string, it would be modified in
the superblock.  (Fortunately it only happens on file systems with a
1k block size.)

Signed-off-by: Theodore Ts'o 
Signed-off-by: Jiri Slaby