linux-stable.git/fs/ext4, branch v4.4.159

ext4: don't mark mmp buffer head dirty

2018-09-29T10:08:54+00:00

commit fe18d649891d813964d3aaeebad873f281627fbc upstream.

Marking mmp bh dirty before writing it will make writeback
pick up mmp block later and submit a write, we don't want the
duplicate write as kmmpd thread should have full control of
reading and writing the mmp block.
Another reason is we will also have random I/O error on
the writeback request when blk integrity is enabled, because
kmmpd could modify the content of the mmp block(e.g. setting
new seq and time) while the mmp block is under I/O requested
by writeback.

Signed-off-by: Li Dongyang 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Andreas Dilger 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

ext4: fix online resizing for bigalloc file systems with a 1k block size

2018-09-29T10:08:54+00:00

commit 5f8c10936fab2b69a487400f2872902e597dd320 upstream.

An online resize of a file system with the bigalloc feature enabled
and a 1k block size would be refused since ext4_resize_begin() did not
understand s_first_data_block is 0 for all bigalloc file systems, even
when the block size is 1k.

Signed-off-by: Theodore Ts'o 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

ext4: fix online resize's handling of a too-small final block group

2018-09-29T10:08:54+00:00

commit f0a459dec5495a3580f8d784555e6f8f3bf7f263 upstream.

Avoid growing the file system to an extent so that the last block
group is too small to hold all of the metadata that must be stored in
the block group.

This problem can be triggered with the following reproducer:

umount /mnt
mke2fs -F -m0 -b 4096 -t ext4 -O resize_inode,^has_journal \
	-E resize=1073741824 /tmp/foo.img 128M
mount /tmp/foo.img /mnt
truncate --size 1708M /tmp/foo.img
resize2fs /dev/loop0 295400
umount /mnt
e2fsck -fy /tmp/foo.img

Reported-by: Torsten Hilbrich 
Signed-off-by: Theodore Ts'o 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

ext4: recalucate superblock checksum after updating free blocks/inodes

2018-09-29T10:08:54+00:00

commit 4274f516d4bc50648a4d97e4f67ecbd7b65cde4a upstream.

When mounting the superblock, ext4_fill_super() calculates the free
blocks and free inodes and stores them in the superblock.  It's not
strictly necessary, since we don't use them any more, but it's nice to
keep them roughly aligned to reality.

Since it's not critical for file system correctness, the code doesn't
call ext4_commit_super().  The problem is that it's in
ext4_commit_super() that we recalculate the superblock checksum.  So
if we're not going to call ext4_commit_super(), we need to call
ext4_superblock_csum_set() to make sure the superblock checksum is
consistent.

Most of the time, this doesn't matter, since we end up calling
ext4_commit_super() very soon thereafter, and definitely by the time
the file system is unmounted.  However, it doesn't work in this
sequence:

mke2fs -Fq -t ext4 /dev/vdc 128M
mount /dev/vdc /vdc
cp xfstests/git-versions /vdc
godown /vdc
umount /vdc
mount /dev/vdc
tune2fs -l /dev/vdc

With this commit, the "tune2fs -l" no longer fails.

Reported-by: Chengguang Xu 
Signed-off-by: Theodore Ts'o 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

ext4: avoid divide by zero fault when deleting corrupted inline directories

2018-09-29T10:08:53+00:00

commit 4d982e25d0bdc83d8c64e66fdeca0b89240b3b85 upstream.

A specially crafted file system can trick empty_inline_dir() into
reading past the last valid entry in a inline directory, and then run
into the end of xattr marker. This will trigger a divide by zero
fault.  Fix this by using the size of the inline directory instead of
dir->i_size.

Also clean up error reporting in __ext4_check_dir_entry so that the
message is clearer and more understandable --- and avoids the division
by zero trap if the size passed in is zero.  (I'm not sure why we
coded it that way in the first place; printing offset % size is
actually more confusing and less useful.)

https://bugzilla.kernel.org/show_bug.cgi?id=200933

Signed-off-by: Theodore Ts'o 
Reported-by: Wen Xu 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

ext4: reset error code in ext4_find_entry in fallback

2018-09-05T07:18:38+00:00

commit f39b3f45dbcb0343822cce31ea7636ad66e60bc2 upstream.

When ext4_find_entry() falls back to "searching the old fashioned
way" due to a corrupt dx dir, it needs to reset the error code
to NULL so that the nonstandard ERR_BAD_DX_DIR code isn't returned
to userspace.

https://bugzilla.kernel.org/show_bug.cgi?id=199947

Reported-by: Anatoly Trosinenko 
Reviewed-by: Andreas Dilger 
Signed-off-by: Eric Sandeen 
Signed-off-by: Theodore Ts'o 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

ext4: sysfs: print ext4_super_block fields as little-endian

2018-09-05T07:18:38+00:00

commit a4d2aadca184ece182418950d45ba4ffc7b652d2 upstream.

While working on extended rand for last_error/first_error timestamps,
I noticed that the endianess is wrong; we access the little-endian
fields in struct ext4_super_block as native-endian when we print them.

This adds a special case in ext4_attr_show() and ext4_attr_store()
to byteswap the superblock fields if needed.

In older kernels, this code was part of super.c, it got moved to
sysfs.c in linux-4.4.

Cc: stable@vger.kernel.org
Fixes: 52c198c6820f ("ext4: add sysfs entry showing whether the fs contains errors")
Reviewed-by: Andreas Dilger 
Signed-off-by: Arnd Bergmann 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: check for NUL characters in extended attribute's name

2018-09-05T07:18:37+00:00

commit 7d95178c77014dbd8dce36ee40bbbc5e6c121ff5 upstream.

Extended attribute names are defined to be NUL-terminated, so the name
must not contain a NUL character.  This is important because there are
places when remove extended attribute, the code uses strlen to
determine the length of the entry.  That should probably be fixed at
some point, but code is currently really messy, so the simplest fix
for now is to simply validate that the extended attributes are sane.

https://bugzilla.kernel.org/show_bug.cgi?id=200401

Reported-by: Wen Xu 
Signed-off-by: Theodore Ts'o 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

ext4: fix spectre gadget in ext4_mb_regular_allocator()

2018-08-24T11:27:00+00:00

commit 1a5d5e5d51e75a5bca67dadbcea8c841934b7b85 upstream.

'ac->ac_g_ex.fe_len' is a user-controlled value which is used in the
derivation of 'ac->ac_2order'. 'ac->ac_2order', in turn, is used to
index arrays which makes it a potential spectre gadget. Fix this by
sanitizing the value assigned to 'ac->ac2_order'.  This covers the
following accesses found with the help of smatch:

* fs/ext4/mballoc.c:1896 ext4_mb_simple_scan_group() warn: potential
  spectre issue 'grp->bb_counters' [w] (local cap)

* fs/ext4/mballoc.c:445 mb_find_buddy() warn: potential spectre issue
  'EXT4_SB(e4b->bd_sb)->s_mb_offsets' [r] (local cap)

* fs/ext4/mballoc.c:446 mb_find_buddy() warn: potential spectre issue
  'EXT4_SB(e4b->bd_sb)->s_mb_maxs' [r] (local cap)

Suggested-by: Josh Poimboeuf 
Signed-off-by: Jeremy Cline 
Signed-off-by: Theodore Ts'o 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

ext4: fix check to prevent initializing reserved inodes

2018-08-15T15:42:04+00:00

commit 5012284700775a4e6e3fbe7eac4c543c4874b559 upstream.

Commit 8844618d8aa7: "ext4: only look at the bg_flags field if it is
valid" will complain if block group zero does not have the
EXT4_BG_INODE_ZEROED flag set.  Unfortunately, this is not correct,
since a freshly created file system has this flag cleared.  It gets
almost immediately after the file system is mounted read-write --- but
the following somewhat unlikely sequence will end up triggering a
false positive report of a corrupted file system:

   mkfs.ext4 /dev/vdc
   mount -o ro /dev/vdc /vdc
   mount -o remount,rw /dev/vdc

Instead, when initializing the inode table for block group zero, test
to make sure that itable_unused count is not too large, since that is
the case that will result in some or all of the reserved inodes
getting cleared.

This fixes the failures reported by Eric Whiteney when running
generic/230 and generic/231 in the the nojournal test case.

Fixes: 8844618d8aa7 ("ext4: only look at the bg_flags field if it is valid")
Reported-by: Eric Whitney 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman