linux-stable.git/fs/ext4, branch v4.19.78

ext4: fix potential use after free after remounting with noblock_validity

2019-10-07T16:57:05+00:00

[ Upstream commit 7727ae52975d4f4ef7ff69ed8e6e25f6a4168158 ]

Remount process will release system zone which was allocated before if
"noblock_validity" is specified. If we mount an ext4 file system to two
mountpoints with default mount options, and then remount one of them
with "noblock_validity", it may trigger a use after free problem when
someone accessing the other one.

 # mount /dev/sda foo
 # mount /dev/sda bar

User access mountpoint "foo"   |   Remount mountpoint "bar"
                               |
ext4_map_blocks()              |   ext4_remount()
check_block_validity()         |   ext4_setup_system_zone()
ext4_data_block_valid()        |   ext4_release_system_zone()
                               |   free system_blks rb nodes
access system_blks rb nodes    |
trigger use after free         |

This problem can also be reproduced by one mountpint, At the same time,
add_system_zone() can get called during remount as well so there can be
racing ext4_data_block_valid() reading the rbtree at the same time.

This patch add RCU to protect system zone from releasing or building
when doing a remount which inverse current "noblock_validity" mount
option. It assign the rbtree after the whole tree was complete and
do actual freeing after rcu grace period, avoid any intermediate state.

Reported-by: syzbot+1e470567330b7ad711d5@syzkaller.appspotmail.com
Signed-off-by: zhangyi (F) 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Jan Kara 
Signed-off-by: Sasha Levin

ext4: fix punch hole for inline_data file systems

2019-10-05T11:10:11+00:00

commit c1e8220bd316d8ae8e524df39534b8a412a45d5e upstream.

If a program attempts to punch a hole on an inline data file, we need
to convert it to a normal file first.

This was detected using ext4/032 using the adv configuration.  Simple
reproducer:

mke2fs -Fq -t ext4 -O inline_data /dev/vdc
mount /vdc
echo "" > /vdc/testfile
xfs_io -c 'truncate 33554432' /vdc/testfile
xfs_io -c 'fpunch 0 1048576' /vdc/testfile
umount /vdc
e2fsck -fy /dev/vdc

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

ext4: fix warning inside ext4_convert_unwritten_extents_endio

2019-10-05T11:10:11+00:00

commit e3d550c2c4f2f3dba469bc3c4b83d9332b4e99e1 upstream.

Really enable warning when CONFIG_EXT4_DEBUG is set and fix missing
first argument.  This was introduced in commit ff95ec22cd7f ("ext4:
add warning to ext4_convert_unwritten_extents_endio") and splitting
extents inside endio would trigger it.

Fixes: ff95ec22cd7f ("ext4: add warning to ext4_convert_unwritten_extents_endio")
Signed-off-by: Rakesh Pandit 
Signed-off-by: Theodore Ts'o 
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman

ext4: unsigned int compared against zero

2019-09-16T06:22:24+00:00

[ Upstream commit fbbbbd2f28aec991f3fbc248df211550fbdfd58c ]

There are two cases where u32 variables n and err are being checked
for less than zero error values, the checks is always false because
the variables are not signed. Fix this by making the variables ints.

Addresses-Coverity: ("Unsigned compared against 0")
Fixes: 345c0dbf3a30 ("ext4: protect journal inode's blocks using block_validity")
Signed-off-by: Colin Ian King 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin

ext4: fix block validity checks for journal inodes using indirect blocks

2019-09-16T06:22:24+00:00

[ Upstream commit 170417c8c7bb2cbbdd949bf5c443c0c8f24a203b ]

Commit 345c0dbf3a30 ("ext4: protect journal inode's blocks using
block_validity") failed to add an exception for the journal inode in
ext4_check_blockref(), which is the function used by ext4_get_branch()
for indirect blocks.  This caused attempts to read from the ext3-style
journals to fail with:

[  848.968550] EXT4-fs error (device sdb7): ext4_get_branch:171: inode #8: block 30343695: comm jbd2/sdb7-8: invalid block

Fix this by adding the missing exception check.

Fixes: 345c0dbf3a30 ("ext4: protect journal inode's blocks using block_validity")
Reported-by: Arthur Marsh 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin

ext4: don't perform block validity checks on the journal inode

2019-09-16T06:22:24+00:00

[ Upstream commit 0a944e8a6c66ca04c7afbaa17e22bf208a8b37f0 ]

Since the journal inode is already checked when we added it to the
block validity's system zone, if we check it again, we'll just trigger
a failure.

This was causing failures like this:

[   53.897001] EXT4-fs error (device sda): ext4_find_extent:909: inode
#8: comm jbd2/sda-8: pblk 121667583 bad header/extent: invalid extent entries - magic f30a, entries 8, max 340(340), depth 0(0)
[   53.931430] jbd2_journal_bmap: journal block not found at offset 49 on sda-8
[   53.938480] Aborting journal on device sda-8.

... but only if the system was under enough memory pressure that
logical->physical mapping for the journal inode gets pushed out of the
extent cache.  (This is why it wasn't noticed earlier.)

Fixes: 345c0dbf3a30 ("ext4: protect journal inode's blocks using block_validity")
Reported-by: Dan Rue 
Signed-off-by: Theodore Ts'o 
Tested-by: Naresh Kamboju 
Signed-off-by: Sasha Levin

ext4: protect journal inode's blocks using block_validity

2019-09-16T06:22:11+00:00

[ Upstream commit 345c0dbf3a30872d9b204db96b5857cd00808cae ]

Add the blocks which belong to the journal inode to block_validity's
system zone so attempts to deallocate or overwrite the journal due a
corrupted file system where the journal blocks are also claimed by
another inode.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202879
Signed-off-by: Theodore Ts'o 
Cc: stable@kernel.org
Signed-off-by: Sasha Levin

ext4: allow directory holes

2019-07-28T06:29:30+00:00

commit 4e19d6b65fb4fc42e352ce9883649e049da14743 upstream.

The largedir feature was intended to allow ext4 directories to have
unmapped directory blocks (e.g., directory holes).  And so the
released e2fsprogs no longer enforces this for largedir file systems;
however, the corresponding change to the kernel-side code was not made.

This commit fixes this oversight.

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

ext4: use jbd2_inode dirty range scoping

2019-07-28T06:29:29+00:00

commit 73131fbb003b3691cfcf9656f234b00da497fcd6 upstream.

Use the newly introduced jbd2_inode dirty range scoping to prevent us
from waiting forever when trying to complete a journal transaction.

Signed-off-by: Ross Zwisler 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Jan Kara 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

ext4: enforce the immutable flag on open files

2019-07-28T06:29:29+00:00

commit 02b016ca7f99229ae6227e7b2fc950c4e140d74a upstream.

According to the chattr man page, "a file with the 'i' attribute
cannot be modified..."  Historically, this was only enforced when the
file was opened, per the rest of the description, "... and the file
can not be opened in write mode".

There is general agreement that we should standardize all file systems
to prevent modifications even for files that were opened at the time
the immutable flag is set.  Eventually, a change to enforce this at
the VFS layer should be landing in mainline.  Until then, enforce this
at the ext4 level to prevent xfstests generic/553 from failing.

Signed-off-by: Theodore Ts'o 
Cc: "Darrick J. Wong" 
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman