Commit graph

57016 commits

Author SHA1 Message Date
Jan Kara
7c3d77a31b writeback: Fix sync livelock due to b_dirty_time processing
commit f9cae926f35e8230330f28c7b743ad088611a8de upstream.

When we are processing writeback for sync(2), move_expired_inodes()
didn't set any inode expiry value (older_than_this). This can result in
writeback never completing if there's steady stream of inodes added to
b_dirty_time list as writeback rechecks dirty lists after each writeback
round whether there's more work to be done. Fix the problem by using
sync(2) start time is inode expiry value when processing b_dirty_time
list similarly as for ordinarily dirtied inodes. This requires some
refactoring of older_than_this handling which simplifies the code
noticeably as a bonus.

Fixes: 0ae45f63d4 ("vfs: add support for a lazytime mount option")
CC: stable@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-03 11:24:28 +02:00
Jan Kara
be0937e03b writeback: Avoid skipping inode writeback
commit 5afced3bf28100d81fb2fe7e98918632a08feaf5 upstream.

Inode's i_io_list list head is used to attach inode to several different
lists - wb->{b_dirty, b_dirty_time, b_io, b_more_io}. When flush worker
prepares a list of inodes to writeback e.g. for sync(2), it moves inodes
to b_io list. Thus it is critical for sync(2) data integrity guarantees
that inode is not requeued to any other writeback list when inode is
queued for processing by flush worker. That's the reason why
writeback_single_inode() does not touch i_io_list (unless the inode is
completely clean) and why __mark_inode_dirty() does not touch i_io_list
if I_SYNC flag is set.

However there are two flaws in the current logic:

1) When inode has only I_DIRTY_TIME set but it is already queued in b_io
list due to sync(2), concurrent __mark_inode_dirty(inode, I_DIRTY_SYNC)
can still move inode back to b_dirty list resulting in skipping
writeback of inode time stamps during sync(2).

2) When inode is on b_dirty_time list and writeback_single_inode() races
with __mark_inode_dirty() like:

writeback_single_inode()		__mark_inode_dirty(inode, I_DIRTY_PAGES)
  inode->i_state |= I_SYNC
  __writeback_single_inode()
					  inode->i_state |= I_DIRTY_PAGES;
					  if (inode->i_state & I_SYNC)
					    bail
  if (!(inode->i_state & I_DIRTY_ALL))
  - not true so nothing done

We end up with I_DIRTY_PAGES inode on b_dirty_time list and thus
standard background writeback will not writeback this inode leading to
possible dirty throttling stalls etc. (thanks to Martijn Coenen for this
analysis).

Fix these problems by tracking whether inode is queued in b_io or
b_more_io lists in a new I_SYNC_QUEUED flag. When this flag is set, we
know flush worker has queued inode and we should not touch i_io_list.
On the other hand we also know that once flush worker is done with the
inode it will requeue the inode to appropriate dirty list. When
I_SYNC_QUEUED is not set, __mark_inode_dirty() can (and must) move inode
to appropriate dirty list.

Reported-by: Martijn Coenen <maco@android.com>
Reviewed-by: Martijn Coenen <maco@android.com>
Tested-by: Martijn Coenen <maco@android.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Fixes: 0ae45f63d4 ("vfs: add support for a lazytime mount option")
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-03 11:24:28 +02:00
Jan Kara
1f58ddc07e writeback: Protect inode->i_io_list with inode->i_lock
commit b35250c0816c7cf7d0a8de92f5fafb6a7508a708 upstream.

Currently, operations on inode->i_io_list are protected by
wb->list_lock. In the following patches we'll need to maintain
consistency between inode->i_state and inode->i_io_list so change the
code so that inode->i_lock protects also all inode's i_io_list handling.

Reviewed-by: Martijn Coenen <maco@android.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
CC: stable@vger.kernel.org # Prerequisite for "writeback: Avoid skipping inode writeback"
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-03 11:24:28 +02:00
Filipe Manana
b0186a11df btrfs: fix space cache memory leak after transaction abort
commit bbc37d6e475eee8ffa2156ec813efc6bbb43c06d upstream.

If a transaction aborts it can cause a memory leak of the pages array of
a block group's io_ctl structure. The following steps explain how that can
happen:

1) Transaction N is committing, currently in state TRANS_STATE_UNBLOCKED
   and it's about to start writing out dirty extent buffers;

2) Transaction N + 1 already started and another task, task A, just called
   btrfs_commit_transaction() on it;

3) Block group B was dirtied (extents allocated from it) by transaction
   N + 1, so when task A calls btrfs_start_dirty_block_groups(), at the
   very beginning of the transaction commit, it starts writeback for the
   block group's space cache by calling btrfs_write_out_cache(), which
   allocates the pages array for the block group's io_ctl with a call to
   io_ctl_init(). Block group A is added to the io_list of transaction
   N + 1 by btrfs_start_dirty_block_groups();

4) While transaction N's commit is writing out the extent buffers, it gets
   an IO error and aborts transaction N, also setting the file system to
   RO mode;

5) Task A has already returned from btrfs_start_dirty_block_groups(), is at
   btrfs_commit_transaction() and has set transaction N + 1 state to
   TRANS_STATE_COMMIT_START. Immediately after that it checks that the
   filesystem was turned to RO mode, due to transaction N's abort, and
   jumps to the "cleanup_transaction" label. After that we end up at
   btrfs_cleanup_one_transaction() which calls btrfs_cleanup_dirty_bgs().
   That helper finds block group B in the transaction's io_list but it
   never releases the pages array of the block group's io_ctl, resulting in
   a memory leak.

In fact at the point when we are at btrfs_cleanup_dirty_bgs(), the pages
array points to pages that were already released by us at
__btrfs_write_out_cache() through the call to io_ctl_drop_pages(). We end
up freeing the pages array only after waiting for the ordered extent to
complete through btrfs_wait_cache_io(), which calls io_ctl_free() to do
that. But in the transaction abort case we don't wait for the space cache's
ordered extent to complete through a call to btrfs_wait_cache_io(), so
that's why we end up with a memory leak - we wait for the ordered extent
to complete indirectly by shutting down the work queues and waiting for
any jobs in them to complete before returning from close_ctree().

We can solve the leak simply by freeing the pages array right after
releasing the pages (with the call to io_ctl_drop_pages()) at
__btrfs_write_out_cache(), since we will never use it anymore after that
and the pages array points to already released pages at that point, which
is currently not a problem since no one will use it after that, but not a
good practice anyway since it can easily lead to use-after-free issues.

So fix this by freeing the pages array right after releasing the pages at
__btrfs_write_out_cache().

This issue can often be reproduced with test case generic/475 from fstests
and kmemleak can detect it and reports it with the following trace:

unreferenced object 0xffff9bbf009fa600 (size 512):
  comm "fsstress", pid 38807, jiffies 4298504428 (age 22.028s)
  hex dump (first 32 bytes):
    00 a0 7c 4d 3d ed ff ff 40 a0 7c 4d 3d ed ff ff  ..|M=...@.|M=...
    80 a0 7c 4d 3d ed ff ff c0 a0 7c 4d 3d ed ff ff  ..|M=.....|M=...
  backtrace:
    [<00000000f4b5cfe2>] __kmalloc+0x1a8/0x3e0
    [<0000000028665e7f>] io_ctl_init+0xa7/0x120 [btrfs]
    [<00000000a1f95b2d>] __btrfs_write_out_cache+0x86/0x4a0 [btrfs]
    [<00000000207ea1b0>] btrfs_write_out_cache+0x7f/0xf0 [btrfs]
    [<00000000af21f534>] btrfs_start_dirty_block_groups+0x27b/0x580 [btrfs]
    [<00000000c3c23d44>] btrfs_commit_transaction+0xa6f/0xe70 [btrfs]
    [<000000009588930c>] create_subvol+0x581/0x9a0 [btrfs]
    [<000000009ef2fd7f>] btrfs_mksubvol+0x3fb/0x4a0 [btrfs]
    [<00000000474e5187>] __btrfs_ioctl_snap_create+0x119/0x1a0 [btrfs]
    [<00000000708ee349>] btrfs_ioctl_snap_create_v2+0xb0/0xf0 [btrfs]
    [<00000000ea60106f>] btrfs_ioctl+0x12c/0x3130 [btrfs]
    [<000000005c923d6d>] __x64_sys_ioctl+0x83/0xb0
    [<0000000043ace2c9>] do_syscall_64+0x33/0x80
    [<00000000904efbce>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-03 11:24:26 +02:00
Marcos Paulo de Souza
ee203be4df btrfs: reset compression level for lzo on remount
commit 282dd7d7718444679b046b769d872b188818ca35 upstream.

Currently a user can set mount "-o compress" which will set the
compression algorithm to zlib, and use the default compress level for
zlib (3):

  relatime,compress=zlib:3,space_cache

If the user remounts the fs using "-o compress=lzo", then the old
compress_level is used:

  relatime,compress=lzo:3,space_cache

But lzo does not expose any tunable compression level. The same happens
if we set any compress argument with different level, also with zstd.

Fix this by resetting the compress_level when compress=lzo is
specified.  With the fix applied, lzo is shown without compress level:

  relatime,compress=lzo,space_cache

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-03 11:24:26 +02:00
Xianting Tian
4aaac9c537 fs: prevent BUG_ON in submit_bh_wbc()
[ Upstream commit 377254b2cd2252c7c3151b113cbdf93a7736c2e9 ]

If a device is hot-removed --- for example, when a physical device is
unplugged from pcie slot or a nbd device's network is shutdown ---
this can result in a BUG_ON() crash in submit_bh_wbc().  This is
because the when the block device dies, the buffer heads will have
their Buffer_Mapped flag get cleared, leading to the crash in
submit_bh_wbc.

We had attempted to work around this problem in commit a17712c8
("ext4: check superblock mapped prior to committing").  Unfortunately,
it's still possible to hit the BUG_ON(!buffer_mapped(bh)) if the
device dies between when the work-around check in ext4_commit_super()
and when submit_bh_wbh() is finally called:

Code path:
ext4_commit_super
    judge if 'buffer_mapped(sbh)' is false, return <== commit a17712c8
          lock_buffer(sbh)
          ...
          unlock_buffer(sbh)
               __sync_dirty_buffer(sbh,...
                    lock_buffer(sbh)
                        judge if 'buffer_mapped(sbh))' is false, return <== added by this patch
                            submit_bh(...,sbh)
                                submit_bh_wbc(...,sbh,...)

[100722.966497] kernel BUG at fs/buffer.c:3095! <== BUG_ON(!buffer_mapped(bh))' in submit_bh_wbc()
[100722.966503] invalid opcode: 0000 [#1] SMP
[100722.966566] task: ffff8817e15a9e40 task.stack: ffffc90024744000
[100722.966574] RIP: 0010:submit_bh_wbc+0x180/0x190
[100722.966575] RSP: 0018:ffffc90024747a90 EFLAGS: 00010246
[100722.966576] RAX: 0000000000620005 RBX: ffff8818a80603a8 RCX: 0000000000000000
[100722.966576] RDX: ffff8818a80603a8 RSI: 0000000000020800 RDI: 0000000000000001
[100722.966577] RBP: ffffc90024747ac0 R08: 0000000000000000 R09: ffff88207f94170d
[100722.966578] R10: 00000000000437c8 R11: 0000000000000001 R12: 0000000000020800
[100722.966578] R13: 0000000000000001 R14: 000000000bf9a438 R15: ffff88195f333000
[100722.966580] FS:  00007fa2eee27700(0000) GS:ffff88203d840000(0000) knlGS:0000000000000000
[100722.966580] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[100722.966581] CR2: 0000000000f0b008 CR3: 000000201a622003 CR4: 00000000007606e0
[100722.966582] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[100722.966583] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[100722.966583] PKRU: 55555554
[100722.966583] Call Trace:
[100722.966588]  __sync_dirty_buffer+0x6e/0xd0
[100722.966614]  ext4_commit_super+0x1d8/0x290 [ext4]
[100722.966626]  __ext4_std_error+0x78/0x100 [ext4]
[100722.966635]  ? __ext4_journal_get_write_access+0xca/0x120 [ext4]
[100722.966646]  ext4_reserve_inode_write+0x58/0xb0 [ext4]
[100722.966655]  ? ext4_dirty_inode+0x48/0x70 [ext4]
[100722.966663]  ext4_mark_inode_dirty+0x53/0x1e0 [ext4]
[100722.966671]  ? __ext4_journal_start_sb+0x6d/0xf0 [ext4]
[100722.966679]  ext4_dirty_inode+0x48/0x70 [ext4]
[100722.966682]  __mark_inode_dirty+0x17f/0x350
[100722.966686]  generic_update_time+0x87/0xd0
[100722.966687]  touch_atime+0xa9/0xd0
[100722.966690]  generic_file_read_iter+0xa09/0xcd0
[100722.966694]  ? page_cache_tree_insert+0xb0/0xb0
[100722.966704]  ext4_file_read_iter+0x4a/0x100 [ext4]
[100722.966707]  ? __inode_security_revalidate+0x4f/0x60
[100722.966709]  __vfs_read+0xec/0x160
[100722.966711]  vfs_read+0x8c/0x130
[100722.966712]  SyS_pread64+0x87/0xb0
[100722.966716]  do_syscall_64+0x67/0x1b0
[100722.966719]  entry_SYSCALL64_slow_path+0x25/0x25

To address this, add the check of 'buffer_mapped(bh)' to
__sync_dirty_buffer().  This also has the benefit of fixing this for
other file systems.

With this addition, we can drop the workaround in ext4_commit_supper().

[ Commit description rewritten by tytso. ]

Signed-off-by: Xianting Tian <xianting_tian@126.com>
Link: https://lore.kernel.org/r/1596211825-8750-1-git-send-email-xianting_tian@126.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-03 11:24:24 +02:00
Jan Kara
7f6858a3b9 ext4: correctly restore system zone info when remount fails
[ Upstream commit 0f5bde1db174f6c471f0bd27198575719dabe3e5 ]

When remounting filesystem fails late during remount handling and
block_validity mount option is also changed during the remount, we fail
to restore system zone information to a state matching the mount option.
This is mostly harmless, just the block validity checking will not match
the situation described by the mount option. Make sure these two are always
consistent.

Reported-by: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200728130437.7804-7-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-03 11:24:24 +02:00
Jan Kara
c279f7a44f ext4: handle error of ext4_setup_system_zone() on remount
[ Upstream commit d176b1f62f242ab259ff665a26fbac69db1aecba ]

ext4_setup_system_zone() can fail. Handle the failure in ext4_remount().

Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200728130437.7804-2-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-03 11:24:24 +02:00
Lukas Czerner
bfb8d9b747 ext4: handle option set by mount flags correctly
[ Upstream commit f25391ebb475d3ffb3aa61bb90e3594c841749ef ]

Currently there is a problem with mount options that can be both set by
vfs using mount flags or by a string parsing in ext4.

i_version/iversion options gets lost after remount, for example

$ mount -o i_version /dev/pmem0 /mnt
$ grep pmem0 /proc/self/mountinfo | grep i_version
310 95 259:0 / /mnt rw,relatime shared:163 - ext4 /dev/pmem0 rw,seclabel,i_version
$ mount -o remount,ro /mnt
$ grep pmem0 /proc/self/mountinfo | grep i_version

nolazytime gets ignored by ext4 on remount, for example

$ mount -o lazytime /dev/pmem0 /mnt
$ grep pmem0 /proc/self/mountinfo | grep lazytime
310 95 259:0 / /mnt rw,relatime shared:163 - ext4 /dev/pmem0 rw,lazytime,seclabel
$ mount -o remount,nolazytime /mnt
$ grep pmem0 /proc/self/mountinfo | grep lazytime
310 95 259:0 / /mnt rw,relatime shared:163 - ext4 /dev/pmem0 rw,lazytime,seclabel

Fix it by applying the SB_LAZYTIME and SB_I_VERSION flags from *flags to
s_flags before we parse the option and use the resulting state of the
same flags in *flags at the end of successful remount.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Link: https://lore.kernel.org/r/20200723150526.19931-1-lczerner@redhat.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-03 11:24:24 +02:00
zhangyi (F)
8eed535dad jbd2: abort journal if free a async write error metadata buffer
[ Upstream commit c044f3d8360d2ecf831ba2cc9f08cf9fb2c699fb ]

If we free a metadata buffer which has been failed to async write out
in the background, the jbd2 checkpoint procedure will not detect this
failure in jbd2_log_do_checkpoint(), so it may lead to filesystem
inconsistency after cleanup journal tail. This patch abort the journal
if free a buffer has write_io_error flag to prevent potential further
inconsistency.

Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20200620025427.1756360-5-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-03 11:24:24 +02:00
Lukas Czerner
47788043e5 ext4: handle read only external journal device
[ Upstream commit 273108fa5015eeffc4bacfa5ce272af3434b96e4 ]

Ext4 uses blkdev_get_by_dev() to get the block_device for journal device
which does check to see if the read-only block device was opened
read-only.

As a result ext4 will hapily proceed mounting the file system with
external journal on read-only device. This is bad as we would not be
able to use the journal leading to errors later on.

Instead of simply failing to mount file system in this case, treat it in
a similar way we treat internal journal on read-only device. Allow to
mount with -o noload in read-only mode.

This can be reproduced easily like this:

mke2fs -F -O journal_dev $JOURNAL_DEV 100M
mkfs.$FSTYPE -F -J device=$JOURNAL_DEV $FS_DEV
blockdev --setro $JOURNAL_DEV
mount $FS_DEV $MNT
touch $MNT/file
umount $MNT

leading to error like this

[ 1307.318713] ------------[ cut here ]------------
[ 1307.323362] generic_make_request: Trying to write to read-only block-device dm-2 (partno 0)
[ 1307.331741] WARNING: CPU: 36 PID: 3224 at block/blk-core.c:855 generic_make_request_checks+0x2c3/0x580
[ 1307.341041] Modules linked in: ext4 mbcache jbd2 rfkill intel_rapl_msr intel_rapl_common isst_if_commd
[ 1307.419445] CPU: 36 PID: 3224 Comm: jbd2/dm-2 Tainted: G        W I       5.8.0-rc5 #2
[ 1307.427359] Hardware name: Dell Inc. PowerEdge R740/01KPX8, BIOS 2.3.10 08/15/2019
[ 1307.434932] RIP: 0010:generic_make_request_checks+0x2c3/0x580
[ 1307.440676] Code: 94 03 00 00 48 89 df 48 8d 74 24 08 c6 05 cf 2b 18 01 01 e8 7f a4 ff ff 48 c7 c7 50e
[ 1307.459420] RSP: 0018:ffffc0d70eb5fb48 EFLAGS: 00010286
[ 1307.464646] RAX: 0000000000000000 RBX: ffff9b33b2978300 RCX: 0000000000000000
[ 1307.471780] RDX: ffff9b33e12a81e0 RSI: ffff9b33e1298000 RDI: ffff9b33e1298000
[ 1307.478913] RBP: ffff9b7b9679e0c0 R08: 0000000000000837 R09: 0000000000000024
[ 1307.486044] R10: 0000000000000000 R11: ffffc0d70eb5f9f0 R12: 0000000000000400
[ 1307.493177] R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
[ 1307.500308] FS:  0000000000000000(0000) GS:ffff9b33e1280000(0000) knlGS:0000000000000000
[ 1307.508396] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1307.514142] CR2: 000055eaf4109000 CR3: 0000003dee40a006 CR4: 00000000007606e0
[ 1307.521273] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1307.528407] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 1307.535538] PKRU: 55555554
[ 1307.538250] Call Trace:
[ 1307.540708]  generic_make_request+0x30/0x340
[ 1307.544985]  submit_bio+0x43/0x190
[ 1307.548393]  ? bio_add_page+0x62/0x90
[ 1307.552068]  submit_bh_wbc+0x16a/0x190
[ 1307.555833]  jbd2_write_superblock+0xec/0x200 [jbd2]
[ 1307.560803]  jbd2_journal_update_sb_log_tail+0x65/0xc0 [jbd2]
[ 1307.566557]  jbd2_journal_commit_transaction+0x2ae/0x1860 [jbd2]
[ 1307.572566]  ? check_preempt_curr+0x7a/0x90
[ 1307.576756]  ? update_curr+0xe1/0x1d0
[ 1307.580421]  ? account_entity_dequeue+0x7b/0xb0
[ 1307.584955]  ? newidle_balance+0x231/0x3d0
[ 1307.589056]  ? __switch_to_asm+0x42/0x70
[ 1307.592986]  ? __switch_to_asm+0x36/0x70
[ 1307.596918]  ? lock_timer_base+0x67/0x80
[ 1307.600851]  kjournald2+0xbd/0x270 [jbd2]
[ 1307.604873]  ? finish_wait+0x80/0x80
[ 1307.608460]  ? commit_timeout+0x10/0x10 [jbd2]
[ 1307.612915]  kthread+0x114/0x130
[ 1307.616152]  ? kthread_park+0x80/0x80
[ 1307.619816]  ret_from_fork+0x22/0x30
[ 1307.623400] ---[ end trace 27490236265b1630 ]---

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/20200717090605.2612-1-lczerner@redhat.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-03 11:24:24 +02:00
Jan Kara
a6d49257cb ext4: don't BUG on inconsistent journal feature
[ Upstream commit 11215630aada28307ba555a43138db6ac54fa825 ]

A customer has reported a BUG_ON in ext4_clear_journal_err() hitting
during an LTP testing. Either this has been caused by a test setup
issue where the filesystem was being overwritten while LTP was mounting
it or the journal replay has overwritten the superblock with invalid
data. In either case it is preferable we don't take the machine down
with a BUG_ON. So handle the situation of unexpectedly missing
has_journal feature more gracefully. We issue warning and fail the mount
in the cases where the race window is narrow and the failed check is
most likely a programming error. In cases where fs corruption is more
likely, we do full ext4_error() handling before failing mount / remount.

Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200710140759.18031-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-03 11:24:24 +02:00
Lukas Czerner
3b1a4ea002 jbd2: make sure jh have b_transaction set in refile/unfile_buffer
[ Upstream commit 24dc9864914eb5813173cfa53313fcd02e4aea7d ]

Callers of __jbd2_journal_unfile_buffer() and
__jbd2_journal_refile_buffer() assume that the b_transaction is set. In
fact if it's not, we can end up with journal_head refcounting errors
leading to crash much later that might be very hard to track down. Add
asserts to make sure that is the case.

We also make sure that b_next_transaction is NULL in
__jbd2_journal_unfile_buffer() since the callers expect that as well and
we should not get into that stage in this state anyway, leading to
problems later on if we do.

Tested with fstests.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200617092549.6712-1-lczerner@redhat.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-03 11:24:23 +02:00
Xiubo Li
d033576669 ceph: fix potential mdsc use-after-free crash
[ Upstream commit fa9967734227b44acb1b6918033f9122dc7825b9 ]

Make sure the delayed work stopped before releasing the resources.

cancel_delayed_work_sync() will only guarantee that the work finishes
executing if the work is already in the ->worklist.  That means after
the cancel_delayed_work_sync() returns, it will leave the work requeued
if it was rearmed at the end. That can lead to a use after free once the
work struct is freed.

Fix it by flushing the delayed work instead of trying to cancel it, and
ensure that the work doesn't rearm if the mdsc is stopping.

URL: https://tracker.ceph.com/issues/46293
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-03 11:24:22 +02:00
Qu Wenruo
5d20e391d9 btrfs: file: reserve qgroup space after the hole punch range is locked
[ Upstream commit a7f8b1c2ac21bf081b41264c9cfd6260dffa6246 ]

The incoming qgroup reserved space timing will move the data reservation
to ordered extent completely.

However in btrfs_punch_hole_lock_range() will call
btrfs_invalidate_page(), which will clear QGROUP_RESERVED bit for the
range.

In current stage it's OK, but if we're making ordered extents handle the
reserved space, then btrfs_punch_hole_lock_range() can clear the
QGROUP_RESERVED bit before we submit ordered extent, leading to qgroup
reserved space leakage.

So here change the timing to make reserve data space after
btrfs_punch_hole_lock_range().
The new timing is fine for either current code or the new code.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-03 11:24:22 +02:00
Li Guifu
8cfbac12a6 f2fs: fix use-after-free issue
[ Upstream commit 99c787cfd2bd04926f1f553b30bd7dcea2caaba1 ]

During umount, f2fs_put_super() unregisters procfs entries after
f2fs_destroy_segment_manager(), it may cause use-after-free
issue when umount races with procfs accessing, fix it by relocating
f2fs_unregister_sysfs().

[Chao Yu: change commit title/message a bit]

Signed-off-by: Li Guifu <bluce.liguifu@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-03 11:24:21 +02:00
Chao Yu
9e2c212d7c f2fs: fix error path in do_recover_data()
[ Upstream commit 9627a7b31f3c4ff8bc8f3be3683983ffe6eaebe6 ]

- don't panic kernel if f2fs_get_node_page() fails in
f2fs_recover_inline_data() or f2fs_recover_inline_xattr();
- return error number of f2fs_truncate_blocks() to
f2fs_recover_inline_data()'s caller;

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-03 11:24:20 +02:00
Dave Chinner
6af2bb1451 xfs: Don't allow logging of XFS_ISTALE inodes
[ Upstream commit 96355d5a1f0ee6dcc182c37db4894ec0c29f1692 ]

In tracking down a problem in this patchset, I discovered we are
reclaiming dirty stale inodes. This wasn't discovered until inodes
were always attached to the cluster buffer and then the rcu callback
that freed inodes was assert failing because the inode still had an
active pointer to the cluster buffer after it had been reclaimed.

Debugging the issue indicated that this was a pre-existing issue
resulting from the way the inodes are handled in xfs_inactive_ifree.
When we free a cluster buffer from xfs_ifree_cluster, all the inodes
in cache are marked XFS_ISTALE. Those that are clean have nothing
else done to them and so eventually get cleaned up by background
reclaim. i.e. it is assumed we'll never dirty/relog an inode marked
XFS_ISTALE.

On journal commit dirty stale inodes as are handled by both
buffer and inode log items to run though xfs_istale_done() and
removed from the AIL (buffer log item commit) or the log item will
simply unpin it because the buffer log item will clean it. What happens
to any specific inode is entirely dependent on which log item wins
the commit race, but the result is the same - stale inodes are
clean, not attached to the cluster buffer, and not in the AIL. Hence
inode reclaim can just free these inodes without further care.

However, if the stale inode is relogged, it gets dirtied again and
relogged into the CIL. Most of the time this isn't an issue, because
relogging simply changes the inode's location in the current
checkpoint. Problems arise, however, when the CIL checkpoints
between two transactions in the xfs_inactive_ifree() deferops
processing. This results in the XFS_ISTALE inode being redirtied
and inserted into the CIL without any of the other stale cluster
buffer infrastructure being in place.

Hence on journal commit, it simply gets unpinned, so it remains
dirty in memory. Everything in inode writeback avoids XFS_ISTALE
inodes so it can't be written back, and it is not tracked in the AIL
so there's not even a trigger to attempt to clean the inode. Hence
the inode just sits dirty in memory until inode reclaim comes along,
sees that it is XFS_ISTALE, and goes to reclaim it. This reclaiming
of a dirty inode caused use after free, list corruptions and other
nasty issues later in this patchset.

Hence this patch addresses a violation of the "never log XFS_ISTALE
inodes" caused by the deferops processing rolling a transaction
and relogging a stale inode in xfs_inactive_free. It also adds a
bunch of asserts to catch this problem in debug kernels so that
we don't reintroduce this problem in future.

Reproducer for this issue was generic/558 on a v4 filesystem.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-03 11:24:20 +02:00
Al Viro
dcb6e6efb3 do_epoll_ctl(): clean the failure exits up a bit
commit 52c479697c9b73f628140dcdfcd39ea302d05482 upstream.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-26 10:31:06 +02:00
Marc Zyngier
4957d56414 epoll: Keep a reference on files added to the check list
commit a9ed4a6560b8562b7e2e2bed9527e88001f7b682 upstream.

When adding a new fd to an epoll, and that this new fd is an
epoll fd itself, we recursively scan the fds attached to it
to detect cycles, and add non-epool files to a "check list"
that gets subsequently parsed.

However, this check list isn't completely safe when deletions
can happen concurrently. To sidestep the issue, make sure that
a struct file placed on the check list sees its f_count increased,
ensuring that a concurrent deletion won't result in the file
disapearing from under our feet.

Cc: stable@vger.kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-26 10:31:06 +02:00
David Howells
d676b22edb afs: Fix NULL deref in afs_dynroot_depopulate()
[ Upstream commit 5e0b17b026eb7c6de9baa9b0d45a51b05f05abe1 ]

If an error occurs during the construction of an afs superblock, it's
possible that an error occurs after a superblock is created, but before
we've created the root dentry.  If the superblock has a dynamic root
(ie.  what's normally mounted on /afs), the afs_kill_super() will call
afs_dynroot_depopulate() to unpin any created dentries - but this will
oops if the root hasn't been created yet.

Fix this by skipping that bit of code if there is no root dentry.

This leads to an oops looking like:

	general protection fault, ...
	KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f]
	...
	RIP: 0010:afs_dynroot_depopulate+0x25f/0x529 fs/afs/dynroot.c:385
	...
	Call Trace:
	 afs_kill_super+0x13b/0x180 fs/afs/super.c:535
	 deactivate_locked_super+0x94/0x160 fs/super.c:335
	 afs_get_tree+0x1124/0x1460 fs/afs/super.c:598
	 vfs_get_tree+0x89/0x2f0 fs/super.c:1547
	 do_new_mount fs/namespace.c:2875 [inline]
	 path_mount+0x1387/0x2070 fs/namespace.c:3192
	 do_mount fs/namespace.c:3205 [inline]
	 __do_sys_mount fs/namespace.c:3413 [inline]
	 __se_sys_mount fs/namespace.c:3390 [inline]
	 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3390
	 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

which is oopsing on this line:

	inode_lock(root->d_inode);

presumably because sb->s_root was NULL.

Fixes: 0da0b7fd73 ("afs: Display manually added cells in dynamic root mount")
Reported-by: syzbot+c1eff8205244ae7e11a6@syzkaller.appspotmail.com
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-26 10:31:05 +02:00
Jan Kara
1373f884a0 ext4: don't allow overlapping system zones
[ Upstream commit bf9a379d0980e7413d94cb18dac73db2bfc5f470 ]

Currently, add_system_zone() just silently merges two added system zones
that overlap. However the overlap should not happen and it generally
suggests that some unrelated metadata overlap which indicates the fs is
corrupted. We should have caught such problems earlier (e.g. in
ext4_check_descriptors()) but add this check as another line of defense.
In later patch we also use this for stricter checking of journal inode
extent tree.

Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200728130437.7804-3-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-26 10:31:02 +02:00
Eric Sandeen
b3ddf6ba5e ext4: fix potential negative array index in do_split()
[ Upstream commit 5872331b3d91820e14716632ebb56b1399b34fe1 ]

If for any reason a directory passed to do_split() does not have enough
active entries to exceed half the size of the block, we can end up
iterating over all "count" entries without finding a split point.

In this case, count == move, and split will be zero, and we will
attempt a negative index into map[].

Guard against this by detecting this case, and falling back to
split-to-half-of-count instead; in this case we will still have
plenty of space (> half blocksize) in each split block.

Fixes: ef2b02d3e6 ("ext34: ensure do_split leaves enough free space in both blocks")
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/f53e246b-647c-64bb-16ec-135383c70ad7@redhat.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-26 10:31:02 +02:00
Helge Deller
7c89e40ede fs/signalfd.c: fix inconsistent return codes for signalfd4
[ Upstream commit a089e3fd5a82aea20f3d9ec4caa5f4c65cc2cfcc ]

The kernel signalfd4() syscall returns different error codes when called
either in compat or native mode.  This behaviour makes correct emulation
in qemu and testing programs like LTP more complicated.

Fix the code to always return -in both modes- EFAULT for unaccessible user
memory, and EINVAL when called with an invalid signal mask.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Laurent Vivier <laurent@vivier.eu>
Link: http://lkml.kernel.org/r/20200530100707.GA10159@ls3530.fritz.box
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-26 10:31:02 +02:00
Eiichi Tsukata
c90652abae xfs: Fix UBSAN null-ptr-deref in xfs_sysfs_init
[ Upstream commit 96cf2a2c75567ff56195fe3126d497a2e7e4379f ]

If xfs_sysfs_init is called with parent_kobj == NULL, UBSAN
shows the following warning:

  UBSAN: null-ptr-deref in ./fs/xfs/xfs_sysfs.h:37:23
  member access within null pointer of type 'struct xfs_kobj'
  Call Trace:
   dump_stack+0x10e/0x195
   ubsan_type_mismatch_common+0x241/0x280
   __ubsan_handle_type_mismatch_v1+0x32/0x40
   init_xfs_fs+0x12b/0x28f
   do_one_initcall+0xdd/0x1d0
   do_initcall_level+0x151/0x1b6
   do_initcalls+0x50/0x8f
   do_basic_setup+0x29/0x2b
   kernel_init_freeable+0x19f/0x20b
   kernel_init+0x11/0x1e0
   ret_from_fork+0x22/0x30

Fix it by checking parent_kobj before the code accesses its member.

Signed-off-by: Eiichi Tsukata <devel@etsukata.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
[darrick: minor whitespace edits]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-26 10:31:02 +02:00
Xiubo Li
f831c6c95d ceph: fix use-after-free for fsc->mdsc
[ Upstream commit a7caa88f8b72c136f9a401f498471b8a8e35370d ]

If the ceph_mdsc_init() fails, it will free the mdsc already.

Reported-by: syzbot+b57f46d8d6ea51960b8c@syzkaller.appspotmail.com
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-26 10:31:01 +02:00
Zhe Li
96de3dbf27 jffs2: fix UAF problem
[ Upstream commit 798b7347e4f29553db4b996393caf12f5b233daf ]

The log of UAF problem is listed below.
BUG: KASAN: use-after-free in jffs2_rmdir+0xa4/0x1cc [jffs2] at addr c1f165fc
Read of size 4 by task rm/8283
=============================================================================
BUG kmalloc-32 (Tainted: P    B      O   ): kasan: bad access detected
-----------------------------------------------------------------------------

INFO: Allocated in 0xbbbbbbbb age=3054364 cpu=0 pid=0
        0xb0bba6ef
        jffs2_write_dirent+0x11c/0x9c8 [jffs2]
        __slab_alloc.isra.21.constprop.25+0x2c/0x44
        __kmalloc+0x1dc/0x370
        jffs2_write_dirent+0x11c/0x9c8 [jffs2]
        jffs2_do_unlink+0x328/0x5fc [jffs2]
        jffs2_rmdir+0x110/0x1cc [jffs2]
        vfs_rmdir+0x180/0x268
        do_rmdir+0x2cc/0x300
        ret_from_syscall+0x0/0x3c
INFO: Freed in 0x205b age=3054364 cpu=0 pid=0
        0x2e9173
        jffs2_add_fd_to_list+0x138/0x1dc [jffs2]
        jffs2_add_fd_to_list+0x138/0x1dc [jffs2]
        jffs2_garbage_collect_dirent.isra.3+0x21c/0x288 [jffs2]
        jffs2_garbage_collect_live+0x16bc/0x1800 [jffs2]
        jffs2_garbage_collect_pass+0x678/0x11d4 [jffs2]
        jffs2_garbage_collect_thread+0x1e8/0x3b0 [jffs2]
        kthread+0x1a8/0x1b0
        ret_from_kernel_thread+0x5c/0x64
Call Trace:
[c17ddd20] [c02452d4] kasan_report.part.0+0x298/0x72c (unreliable)
[c17ddda0] [d2509680] jffs2_rmdir+0xa4/0x1cc [jffs2]
[c17dddd0] [c026da04] vfs_rmdir+0x180/0x268
[c17dde00] [c026f4e4] do_rmdir+0x2cc/0x300
[c17ddf40] [c001a658] ret_from_syscall+0x0/0x3c

The root cause is that we don't get "jffs2_inode_info.sem" before
we scan list "jffs2_inode_info.dents" in function jffs2_rmdir.
This patch add codes to get "jffs2_inode_info.sem" before we scan
"jffs2_inode_info.dents" to slove the UAF problem.

Signed-off-by: Zhe Li <lizhe67@huawei.com>
Reviewed-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-26 10:31:01 +02:00
Darrick J. Wong
1bc31e520f xfs: fix inode quota reservation checks
[ Upstream commit f959b5d037e71a4d69b5bf71faffa065d9269b4a ]

xfs_trans_dqresv is the function that we use to make reservations
against resource quotas.  Each resource contains two counters: the
q_core counter, which tracks resources allocated on disk; and the dquot
reservation counter, which tracks how much of that resource has either
been allocated or reserved by threads that are working on metadata
updates.

For disk blocks, we compare the proposed reservation counter against the
hard and soft limits to decide if we're going to fail the operation.
However, for inodes we inexplicably compare against the q_core counter,
not the incore reservation count.

Since the q_core counter is always lower than the reservation count and
we unlock the dquot between reservation and transaction commit, this
means that multiple threads can reserve the last inode count before we
hit the hard limit, and when they commit, we'll be well over the hard
limit.

Fix this by checking against the incore inode reservation counter, since
we would appear to maintain that correctly (and that's what we report in
GETQUOTA).

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-26 10:31:01 +02:00
zhangyi (F)
402ff143b9 jbd2: add the missing unlock_buffer() in the error path of jbd2_write_superblock()
commit ef3f5830b859604eda8723c26d90ab23edc027a4 upstream.

jbd2_write_superblock() is under the buffer lock of journal superblock
before ending that superblock write, so add a missing unlock_buffer() in
in the error path before submitting buffer.

Fixes: 742b06b5628f ("jbd2: check superblock mapped prior to committing")
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20200620061948.2049579-1-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-26 10:30:59 +02:00
Jan Kara
a5d3f789b2 ext4: fix checking of directory entry validity for inline directories
commit 7303cb5bfe845f7d43cd9b2dbd37dbb266efda9b upstream.

ext4_search_dir() and ext4_generic_delete_entry() can be called both for
standard director blocks and for inline directories stored inside inode
or inline xattr space. For the second case we didn't call
ext4_check_dir_entry() with proper constraints that could result in
accepting corrupted directory entry as well as false positive filesystem
errors like:

EXT4-fs error (device dm-0): ext4_search_dir:1395: inode #28320400:
block 113246792: comm dockerd: bad entry in directory: directory entry too
close to block end - offset=0, inode=28320403, rec_len=32, name_len=8,
size=4096

Fix the arguments passed to ext4_check_dir_entry().

Fixes: 109ba779d6cc ("ext4: check for directory entries too close to block end")
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200731162135.8080-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-26 10:30:59 +02:00
Jann Horn
9660983738 romfs: fix uninitialized memory leak in romfs_dev_read()
commit bcf85fcedfdd17911982a3e3564fcfec7b01eebd upstream.

romfs has a superblock field that limits the size of the filesystem; data
beyond that limit is never accessed.

romfs_dev_read() fetches a caller-supplied number of bytes from the
backing device.  It returns 0 on success or an error code on failure;
therefore, its API can't represent short reads, it's all-or-nothing.

However, when romfs_dev_read() detects that the requested operation would
cross the filesystem size limit, it currently silently truncates the
requested number of bytes.  This e.g.  means that when the content of a
file with size 0x1000 starts one byte before the filesystem size limit,
->readpage() will only fill a single byte of the supplied page while
leaving the rest uninitialized, leaking that uninitialized memory to
userspace.

Fix it by returning an error code instead of truncating the read when the
requested read operation would go beyond the end of the filesystem.

Fixes: da4458bda2 ("NOMMU: Make it possible for RomFS to use MTD devices directly")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: David Howells <dhowells@redhat.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200818013202.2246365-1-jannh@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-26 10:30:59 +02:00
Josef Bacik
76c3819639 btrfs: sysfs: use NOFS for device creation
[ Upstream commit a47bd78d0c44621efb98b525d04d60dc4d1a79b0 ]

Dave hit this splat during testing btrfs/078:

  ======================================================
  WARNING: possible circular locking dependency detected
  5.8.0-rc6-default+ #1191 Not tainted
  ------------------------------------------------------
  kswapd0/75 is trying to acquire lock:
  ffffa040e9d04ff8 (&delayed_node->mutex){+.+.}-{3:3}, at: __btrfs_release_delayed_node.part.0+0x3f/0x310 [btrfs]

  but task is already holding lock:
  ffffffff8b0c8040 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x5/0x30

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #2 (fs_reclaim){+.+.}-{0:0}:
	 __lock_acquire+0x56f/0xaa0
	 lock_acquire+0xa3/0x440
	 fs_reclaim_acquire.part.0+0x25/0x30
	 __kmalloc_track_caller+0x49/0x330
	 kstrdup+0x2e/0x60
	 __kernfs_new_node.constprop.0+0x44/0x250
	 kernfs_new_node+0x25/0x50
	 kernfs_create_link+0x34/0xa0
	 sysfs_do_create_link_sd+0x5e/0xd0
	 btrfs_sysfs_add_devices_dir+0x65/0x100 [btrfs]
	 btrfs_init_new_device+0x44c/0x12b0 [btrfs]
	 btrfs_ioctl+0xc3c/0x25c0 [btrfs]
	 ksys_ioctl+0x68/0xa0
	 __x64_sys_ioctl+0x16/0x20
	 do_syscall_64+0x50/0xe0
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #1 (&fs_info->chunk_mutex){+.+.}-{3:3}:
	 __lock_acquire+0x56f/0xaa0
	 lock_acquire+0xa3/0x440
	 __mutex_lock+0xa0/0xaf0
	 btrfs_chunk_alloc+0x137/0x3e0 [btrfs]
	 find_free_extent+0xb44/0xfb0 [btrfs]
	 btrfs_reserve_extent+0x9b/0x180 [btrfs]
	 btrfs_alloc_tree_block+0xc1/0x350 [btrfs]
	 alloc_tree_block_no_bg_flush+0x4a/0x60 [btrfs]
	 __btrfs_cow_block+0x143/0x7a0 [btrfs]
	 btrfs_cow_block+0x15f/0x310 [btrfs]
	 push_leaf_right+0x150/0x240 [btrfs]
	 split_leaf+0x3cd/0x6d0 [btrfs]
	 btrfs_search_slot+0xd14/0xf70 [btrfs]
	 btrfs_insert_empty_items+0x64/0xc0 [btrfs]
	 __btrfs_commit_inode_delayed_items+0xb2/0x840 [btrfs]
	 btrfs_async_run_delayed_root+0x10e/0x1d0 [btrfs]
	 btrfs_work_helper+0x2f9/0x650 [btrfs]
	 process_one_work+0x22c/0x600
	 worker_thread+0x50/0x3b0
	 kthread+0x137/0x150
	 ret_from_fork+0x1f/0x30

  -> #0 (&delayed_node->mutex){+.+.}-{3:3}:
	 check_prev_add+0x98/0xa20
	 validate_chain+0xa8c/0x2a00
	 __lock_acquire+0x56f/0xaa0
	 lock_acquire+0xa3/0x440
	 __mutex_lock+0xa0/0xaf0
	 __btrfs_release_delayed_node.part.0+0x3f/0x310 [btrfs]
	 btrfs_evict_inode+0x3bf/0x560 [btrfs]
	 evict+0xd6/0x1c0
	 dispose_list+0x48/0x70
	 prune_icache_sb+0x54/0x80
	 super_cache_scan+0x121/0x1a0
	 do_shrink_slab+0x175/0x420
	 shrink_slab+0xb1/0x2e0
	 shrink_node+0x192/0x600
	 balance_pgdat+0x31f/0x750
	 kswapd+0x206/0x510
	 kthread+0x137/0x150
	 ret_from_fork+0x1f/0x30

  other info that might help us debug this:

  Chain exists of:
    &delayed_node->mutex --> &fs_info->chunk_mutex --> fs_reclaim

   Possible unsafe locking scenario:

	 CPU0                    CPU1
	 ----                    ----
    lock(fs_reclaim);
				 lock(&fs_info->chunk_mutex);
				 lock(fs_reclaim);
    lock(&delayed_node->mutex);

   *** DEADLOCK ***

  3 locks held by kswapd0/75:
   #0: ffffffff8b0c8040 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x5/0x30
   #1: ffffffff8b0b50b8 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab+0x54/0x2e0
   #2: ffffa040e057c0e8 (&type->s_umount_key#26){++++}-{3:3}, at: trylock_super+0x16/0x50

  stack backtrace:
  CPU: 2 PID: 75 Comm: kswapd0 Not tainted 5.8.0-rc6-default+ #1191
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014
  Call Trace:
   dump_stack+0x78/0xa0
   check_noncircular+0x16f/0x190
   check_prev_add+0x98/0xa20
   validate_chain+0xa8c/0x2a00
   __lock_acquire+0x56f/0xaa0
   lock_acquire+0xa3/0x440
   ? __btrfs_release_delayed_node.part.0+0x3f/0x310 [btrfs]
   __mutex_lock+0xa0/0xaf0
   ? __btrfs_release_delayed_node.part.0+0x3f/0x310 [btrfs]
   ? __lock_acquire+0x56f/0xaa0
   ? __btrfs_release_delayed_node.part.0+0x3f/0x310 [btrfs]
   ? lock_acquire+0xa3/0x440
   ? btrfs_evict_inode+0x138/0x560 [btrfs]
   ? btrfs_evict_inode+0x2fe/0x560 [btrfs]
   ? __btrfs_release_delayed_node.part.0+0x3f/0x310 [btrfs]
   __btrfs_release_delayed_node.part.0+0x3f/0x310 [btrfs]
   btrfs_evict_inode+0x3bf/0x560 [btrfs]
   evict+0xd6/0x1c0
   dispose_list+0x48/0x70
   prune_icache_sb+0x54/0x80
   super_cache_scan+0x121/0x1a0
   do_shrink_slab+0x175/0x420
   shrink_slab+0xb1/0x2e0
   shrink_node+0x192/0x600
   balance_pgdat+0x31f/0x750
   kswapd+0x206/0x510
   ? _raw_spin_unlock_irqrestore+0x3e/0x50
   ? finish_wait+0x90/0x90
   ? balance_pgdat+0x750/0x750
   kthread+0x137/0x150
   ? kthread_stop+0x2a0/0x2a0
   ret_from_fork+0x1f/0x30

This is because we're holding the chunk_mutex while adding this device
and adding its sysfs entries.  We actually hold different locks in
different places when calling this function, the dev_replace semaphore
for instance in dev replace, so instead of moving this call around
simply wrap it's operations in NOFS.

CC: stable@vger.kernel.org # 4.14+
Reported-by: David Sterba <dsterba@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-26 10:30:59 +02:00
Qu Wenruo
35c1576814 btrfs: inode: fix NULL pointer dereference if inode doesn't need compression
[ Upstream commit 1e6e238c3002ea3611465ce5f32777ddd6a40126 ]

[BUG]
There is a bug report of NULL pointer dereference caused in
compress_file_extent():

  Oops: Kernel access of bad area, sig: 11 [#1]
  LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
  Workqueue: btrfs-delalloc btrfs_delalloc_helper [btrfs]
  NIP [c008000006dd4d34] compress_file_range.constprop.41+0x75c/0x8a0 [btrfs]
  LR [c008000006dd4d1c] compress_file_range.constprop.41+0x744/0x8a0 [btrfs]
  Call Trace:
  [c000000c69093b00] [c008000006dd4d1c] compress_file_range.constprop.41+0x744/0x8a0 [btrfs] (unreliable)
  [c000000c69093bd0] [c008000006dd4ebc] async_cow_start+0x44/0xa0 [btrfs]
  [c000000c69093c10] [c008000006e14824] normal_work_helper+0xdc/0x598 [btrfs]
  [c000000c69093c80] [c0000000001608c0] process_one_work+0x2c0/0x5b0
  [c000000c69093d10] [c000000000160c38] worker_thread+0x88/0x660
  [c000000c69093db0] [c00000000016b55c] kthread+0x1ac/0x1c0
  [c000000c69093e20] [c00000000000b660] ret_from_kernel_thread+0x5c/0x7c
  ---[ end trace f16954aa20d822f6 ]---

[CAUSE]
For the following execution route of compress_file_range(), it's
possible to hit NULL pointer dereference:

 compress_file_extent()
 |- pages = NULL;
 |- start = async_chunk->start = 0;
 |- end = async_chunk = 4095;
 |- nr_pages = 1;
 |- inode_need_compress() == false; <<< Possible, see later explanation
 |  Now, we have nr_pages = 1, pages = NULL
 |- cont:
 |- 		ret = cow_file_range_inline();
 |- 		if (ret <= 0) {
 |-		for (i = 0; i < nr_pages; i++) {
 |-			WARN_ON(pages[i]->mapping);	<<< Crash

To enter above call execution branch, we need the following race:

    Thread 1 (chattr)     |            Thread 2 (writeback)
--------------------------+------------------------------
                          | btrfs_run_delalloc_range
                          | |- inode_need_compress = true
                          | |- cow_file_range_async()
btrfs_ioctl_set_flag()    |
|- binode_flags |=        |
   BTRFS_INODE_NOCOMPRESS |
                          | compress_file_range()
                          | |- inode_need_compress = false
                          | |- nr_page = 1 while pages = NULL
                          | |  Then hit the crash

[FIX]
This patch will fix it by checking @pages before doing accessing it.
This patch is only designed as a hot fix and easy to backport.

More elegant fix may make btrfs only check inode_need_compress() once to
avoid such race, but that would be another story.

Reported-by: Luciano Chavez <chavez@us.ibm.com>
Fixes: 4d3a800ebb ("btrfs: merge nr_pages input and output parameter in compress_pages")
CC: stable@vger.kernel.org # 4.14.x: cecc8d9038d16: btrfs: Move free_pages_out label in inline extent handling branch in compress_file_range
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-26 10:30:58 +02:00
Nikolay Borisov
2a3d84f1c2 btrfs: Move free_pages_out label in inline extent handling branch in compress_file_range
[ Upstream commit cecc8d9038d164eda61fbcd72520975a554ea63e ]

This label is only executed if compress_file_range fails to create an
inline extent. So move its code in the semantically related inline
extent handling branch. No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-26 10:30:58 +02:00
Josef Bacik
f50a0abaf3 btrfs: don't show full path of bind mounts in subvol=
[ Upstream commit 3ef3959b29c4a5bd65526ab310a1a18ae533172a ]

Chris Murphy reported a problem where rpm ostree will bind mount a bunch
of things for whatever voodoo it's doing.  But when it does this
/proc/mounts shows something like

  /dev/sda /mnt/test btrfs rw,relatime,subvolid=256,subvol=/foo 0 0
  /dev/sda /mnt/test/baz btrfs rw,relatime,subvolid=256,subvol=/foo/bar 0 0

Despite subvolid=256 being subvol=/foo.  This is because we're just
spitting out the dentry of the mount point, which in the case of bind
mounts is the source path for the mountpoint.  Instead we should spit
out the path to the actual subvol.  Fix this by looking up the name for
the subvolid we have mounted.  With this fix the same test looks like
this

  /dev/sda /mnt/test btrfs rw,relatime,subvolid=256,subvol=/foo 0 0
  /dev/sda /mnt/test/baz btrfs rw,relatime,subvolid=256,subvol=/foo 0 0

Reported-by: Chris Murphy <chris@colorremedies.com>
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-26 10:30:58 +02:00
Marcos Paulo de Souza
dd39b6f6c2 btrfs: export helpers for subvolume name/id resolution
[ Upstream commit c0c907a47dccf2cf26251a8fb4a8e7a3bf79ce84 ]

The functions will be used outside of export.c and super.c to allow
resolving subvolume name from a given id, eg. for subvolume deletion by
id ioctl.

Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ split from the next patch ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-26 10:30:58 +02:00
Colin Ian King
aefe207d95 fs/ufs: avoid potential u32 multiplication overflow
[ Upstream commit 88b2e9b06381551b707d980627ad0591191f7a2d ]

The 64 bit ino is being compared to the product of two u32 values,
however, the multiplication is being performed using a 32 bit multiply so
there is a potential of an overflow.  To be fully safe, cast uspi->s_ncg
to a u64 to ensure a 64 bit multiplication occurs to avoid any chance of
overflow.

Fixes: f3e2a520f5 ("ufs: NFS support")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Link: http://lkml.kernel.org/r/20200715170355.1081713-1-colin.king@canonical.com
Addresses-Coverity: ("Unintentional integer overflow")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-21 11:05:38 +02:00
Eric Biggers
9f3fb90d30 fs/minix: remove expected error message in block_to_path()
[ Upstream commit f666f9fb9a36f1c833b9d18923572f0e4d304754 ]

When truncating a file to a size within the last allowed logical block,
block_to_path() is called with the *next* block.  This exceeds the limit,
causing the "block %ld too big" error message to be printed.

This case isn't actually an error; there are just no more blocks past that
point.  So, remove this error message.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Qiujun Huang <anenbupt@gmail.com>
Link: http://lkml.kernel.org/r/20200628060846.682158-7-ebiggers@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-21 11:05:38 +02:00
Eric Biggers
c7ac366be0 fs/minix: fix block limit check for V1 filesystems
[ Upstream commit 0a12c4a8069607247cb8edc3b035a664e636fd9a ]

The minix filesystem reads its maximum file size from its on-disk
superblock.  This value isn't necessarily a multiple of the block size.
When it's not, the V1 block mapping code doesn't allow mapping the last
possible block.  Commit 6ed6a722f9 ("minixfs: fix block limit check")
fixed this in the V2 mapping code.  Fix it in the V1 mapping code too.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Qiujun Huang <anenbupt@gmail.com>
Link: http://lkml.kernel.org/r/20200628060846.682158-6-ebiggers@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-21 11:05:38 +02:00
Eric Biggers
95fc841ea8 fs/minix: set s_maxbytes correctly
[ Upstream commit 32ac86efff91a3e4ef8c3d1cadd4559e23c8e73a ]

The minix filesystem leaves super_block::s_maxbytes at MAX_NON_LFS rather
than setting it to the actual filesystem-specific limit.  This is broken
because it means userspace doesn't see the standard behavior like getting
EFBIG and SIGXFSZ when exceeding the maximum file size.

Fix this by setting s_maxbytes correctly.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Qiujun Huang <anenbupt@gmail.com>
Link: http://lkml.kernel.org/r/20200628060846.682158-5-ebiggers@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-21 11:05:38 +02:00
Jeffrey Mitchell
a906b86895 nfs: Fix getxattr kernel panic and memory overflow
[ Upstream commit b4487b93545214a9db8cbf32e86411677b0cca21 ]

Move the buffer size check to decode_attr_security_label() before memcpy()
Only call memcpy() if the buffer is large enough

Fixes: aa9c266962 ("NFS: Client implementation of Labeled-NFS")
Signed-off-by: Jeffrey Mitchell <jeffrey.mitchell@starlab.io>
[Trond: clean up duplicate test of label->len != 0]
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-21 11:05:38 +02:00
Junxiao Bi
73cbb8af7e ocfs2: change slot number type s16 to u16
commit 38d51b2dd171ad973afc1f5faab825ed05a2d5e9 upstream.

Dan Carpenter reported the following static checker warning.

	fs/ocfs2/super.c:1269 ocfs2_parse_options() warn: '(-1)' 65535 can't fit into 32767 'mopt->slot'
	fs/ocfs2/suballoc.c:859 ocfs2_init_inode_steal_slot() warn: '(-1)' 65535 can't fit into 32767 'osb->s_inode_steal_slot'
	fs/ocfs2/suballoc.c:867 ocfs2_init_meta_steal_slot() warn: '(-1)' 65535 can't fit into 32767 'osb->s_meta_steal_slot'

That's because OCFS2_INVALID_SLOT is (u16)-1. Slot number in ocfs2 can be
never negative, so change s16 to u16.

Fixes: 9277f8334ffc ("ocfs2: fix value of OCFS2_INVALID_SLOT")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Gang He <ghe@suse.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200627001259.19757-1-junxiao.bi@oracle.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21 11:05:33 +02:00
Mikulas Patocka
41d71ef2e7 ext2: fix missing percpu_counter_inc
commit bc2fbaa4d3808aef82dd1064a8e61c16549fe956 upstream.

sbi->s_freeinodes_counter is only decreased by the ext2 code, it is never
increased. This patch fixes it.

Note that sbi->s_freeinodes_counter is only used in the algorithm that
tries to find the group for new allocations, so this bug is not easily
visible (the only visibility is that the group finding algorithm selects
inoptinal result).

Link: https://lore.kernel.org/r/alpine.LRH.2.02.2004201538300.19436@file01.intranet.prod.int.rdu2.redhat.com
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21 11:05:32 +02:00
Paul Aurich
d9710cc6bd cifs: Fix leak when handling lease break for cached root fid
commit baf57b56d3604880ccb3956ec6c62ea894f5de99 upstream.

Handling a lease break for the cached root didn't free the
smb2_lease_break_work allocation, resulting in a leak:

    unreferenced object 0xffff98383a5af480 (size 128):
      comm "cifsd", pid 684, jiffies 4294936606 (age 534.868s)
      hex dump (first 32 bytes):
        c0 ff ff ff 1f 00 00 00 88 f4 5a 3a 38 98 ff ff  ..........Z:8...
        88 f4 5a 3a 38 98 ff ff 80 88 d6 8a ff ff ff ff  ..Z:8...........
      backtrace:
        [<0000000068957336>] smb2_is_valid_oplock_break+0x1fa/0x8c0
        [<0000000073b70b9e>] cifs_demultiplex_thread+0x73d/0xcc0
        [<00000000905fa372>] kthread+0x11c/0x150
        [<0000000079378e4e>] ret_from_fork+0x22/0x30

Avoid this leak by only allocating when necessary.

Fixes: a93864d939 ("cifs: add lease tracking to the cached root fid")
Signed-off-by: Paul Aurich <paul@darkrain42.org>
CC: Stable <stable@vger.kernel.org> # v4.18+
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21 11:05:31 +02:00
Pavel Machek
a34b58b5b4 btrfs: fix return value mixup in btrfs_get_extent
commit 881a3a11c2b858fe9b69ef79ac5ee9978a266dc9 upstream.

btrfs_get_extent() sets variable ret, but out: error path expect error
to be in variable err so the error code is lost.

Fixes: 6bf9e4bd6a27 ("btrfs: inode: Verify inode mode to avoid NULL pointer dereference")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Pavel Machek (CIP) <pavel@denx.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21 11:05:30 +02:00
Filipe Manana
183af2d27d btrfs: fix memory leaks after failure to lookup checksums during inode logging
commit 4f26433e9b3eb7a55ed70d8f882ae9cd48ba448b upstream.

While logging an inode, at copy_items(), if we fail to lookup the checksums
for an extent we release the destination path, free the ins_data array and
then return immediately. However a previous iteration of the for loop may
have added checksums to the ordered_sums list, in which case we leak the
memory used by them.

So fix this by making sure we iterate the ordered_sums list and free all
its checksums before returning.

Fixes: 3650860b90 ("Btrfs: remove almost all of the BUG()'s from tree-log.c")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21 11:05:30 +02:00
Josef Bacik
627fa9d807 btrfs: only search for left_info if there is no right_info in try_merge_free_space
commit bf53d4687b8f3f6b752f091eb85f62369a515dfd upstream.

In try_to_merge_free_space we attempt to find entries to the left and
right of the entry we are adding to see if they can be merged.  We
search for an entry past our current info (saved into right_info), and
then if right_info exists and it has a rb_prev() we save the rb_prev()
into left_info.

However there's a slight problem in the case that we have a right_info,
but no entry previous to that entry.  At that point we will search for
an entry just before the info we're attempting to insert.  This will
simply find right_info again, and assign it to left_info, making them
both the same pointer.

Now if right_info _can_ be merged with the range we're inserting, we'll
add it to the info and free right_info.  However further down we'll
access left_info, which was right_info, and thus get a use-after-free.

Fix this by only searching for the left entry if we don't find a right
entry at all.

The CVE referenced had a specially crafted file system that could
trigger this use-after-free. However with the tree checker improvements
we no longer trigger the conditions for the UAF.  But the original
conditions still apply, hence this fix.

Reference: CVE-2019-19448
Fixes: 9630308170 ("Btrfs: use hybrid extents+bitmap rb tree for free space")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21 11:05:30 +02:00
David Sterba
7c1ddfc987 btrfs: fix messages after changing compression level by remount
commit 27942c9971cc405c60432eca9395e514a2ae9f5e upstream.

Reported by Forza on IRC that remounting with compression options does
not reflect the change in level, or at least it does not appear to do so
according to the messages:

  mount -o compress=zstd:1 /dev/sda /mnt
  mount -o remount,compress=zstd:15 /mnt

does not print the change to the level to syslog:

  [   41.366060] BTRFS info (device vda): use zstd compression, level 1
  [   41.368254] BTRFS info (device vda): disk space caching is enabled
  [   41.390429] BTRFS info (device vda): disk space caching is enabled

What really happens is that the message is lost but the level is actualy
changed.

There's another weird output, if compression is reset to 'no':

  [   45.413776] BTRFS info (device vda): use no compression, level 4

To fix that, save the previous compression level and print the message
in that case too and use separate message for 'no' compression.

CC: stable@vger.kernel.org # 4.19+
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21 11:05:30 +02:00
Josef Bacik
35b4a28051 btrfs: open device without device_list_mutex
commit 18c850fdc5a801bad4977b0f1723761d42267e45 upstream.

There's long existed a lockdep splat because we open our bdev's under
the ->device_list_mutex at mount time, which acquires the bd_mutex.
Usually this goes unnoticed, but if you do loopback devices at all
suddenly the bd_mutex comes with a whole host of other dependencies,
which results in the splat when you mount a btrfs file system.

======================================================
WARNING: possible circular locking dependency detected
5.8.0-0.rc3.1.fc33.x86_64+debug #1 Not tainted
------------------------------------------------------
systemd-journal/509 is trying to acquire lock:
ffff970831f84db0 (&fs_info->reloc_mutex){+.+.}-{3:3}, at: btrfs_record_root_in_trans+0x44/0x70 [btrfs]

but task is already holding lock:
ffff97083144d598 (sb_pagefaults){.+.+}-{0:0}, at: btrfs_page_mkwrite+0x59/0x560 [btrfs]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

 -> #6 (sb_pagefaults){.+.+}-{0:0}:
       __sb_start_write+0x13e/0x220
       btrfs_page_mkwrite+0x59/0x560 [btrfs]
       do_page_mkwrite+0x4f/0x130
       do_wp_page+0x3b0/0x4f0
       handle_mm_fault+0xf47/0x1850
       do_user_addr_fault+0x1fc/0x4b0
       exc_page_fault+0x88/0x300
       asm_exc_page_fault+0x1e/0x30

 -> #5 (&mm->mmap_lock#2){++++}-{3:3}:
       __might_fault+0x60/0x80
       _copy_from_user+0x20/0xb0
       get_sg_io_hdr+0x9a/0xb0
       scsi_cmd_ioctl+0x1ea/0x2f0
       cdrom_ioctl+0x3c/0x12b4
       sr_block_ioctl+0xa4/0xd0
       block_ioctl+0x3f/0x50
       ksys_ioctl+0x82/0xc0
       __x64_sys_ioctl+0x16/0x20
       do_syscall_64+0x52/0xb0
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

 -> #4 (&cd->lock){+.+.}-{3:3}:
       __mutex_lock+0x7b/0x820
       sr_block_open+0xa2/0x180
       __blkdev_get+0xdd/0x550
       blkdev_get+0x38/0x150
       do_dentry_open+0x16b/0x3e0
       path_openat+0x3c9/0xa00
       do_filp_open+0x75/0x100
       do_sys_openat2+0x8a/0x140
       __x64_sys_openat+0x46/0x70
       do_syscall_64+0x52/0xb0
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

 -> #3 (&bdev->bd_mutex){+.+.}-{3:3}:
       __mutex_lock+0x7b/0x820
       __blkdev_get+0x6a/0x550
       blkdev_get+0x85/0x150
       blkdev_get_by_path+0x2c/0x70
       btrfs_get_bdev_and_sb+0x1b/0xb0 [btrfs]
       open_fs_devices+0x88/0x240 [btrfs]
       btrfs_open_devices+0x92/0xa0 [btrfs]
       btrfs_mount_root+0x250/0x490 [btrfs]
       legacy_get_tree+0x30/0x50
       vfs_get_tree+0x28/0xc0
       vfs_kern_mount.part.0+0x71/0xb0
       btrfs_mount+0x119/0x380 [btrfs]
       legacy_get_tree+0x30/0x50
       vfs_get_tree+0x28/0xc0
       do_mount+0x8c6/0xca0
       __x64_sys_mount+0x8e/0xd0
       do_syscall_64+0x52/0xb0
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

 -> #2 (&fs_devs->device_list_mutex){+.+.}-{3:3}:
       __mutex_lock+0x7b/0x820
       btrfs_run_dev_stats+0x36/0x420 [btrfs]
       commit_cowonly_roots+0x91/0x2d0 [btrfs]
       btrfs_commit_transaction+0x4e6/0x9f0 [btrfs]
       btrfs_sync_file+0x38a/0x480 [btrfs]
       __x64_sys_fdatasync+0x47/0x80
       do_syscall_64+0x52/0xb0
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

 -> #1 (&fs_info->tree_log_mutex){+.+.}-{3:3}:
       __mutex_lock+0x7b/0x820
       btrfs_commit_transaction+0x48e/0x9f0 [btrfs]
       btrfs_sync_file+0x38a/0x480 [btrfs]
       __x64_sys_fdatasync+0x47/0x80
       do_syscall_64+0x52/0xb0
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

 -> #0 (&fs_info->reloc_mutex){+.+.}-{3:3}:
       __lock_acquire+0x1241/0x20c0
       lock_acquire+0xb0/0x400
       __mutex_lock+0x7b/0x820
       btrfs_record_root_in_trans+0x44/0x70 [btrfs]
       start_transaction+0xd2/0x500 [btrfs]
       btrfs_dirty_inode+0x44/0xd0 [btrfs]
       file_update_time+0xc6/0x120
       btrfs_page_mkwrite+0xda/0x560 [btrfs]
       do_page_mkwrite+0x4f/0x130
       do_wp_page+0x3b0/0x4f0
       handle_mm_fault+0xf47/0x1850
       do_user_addr_fault+0x1fc/0x4b0
       exc_page_fault+0x88/0x300
       asm_exc_page_fault+0x1e/0x30

other info that might help us debug this:

Chain exists of:
  &fs_info->reloc_mutex --> &mm->mmap_lock#2 --> sb_pagefaults

Possible unsafe locking scenario:

     CPU0                    CPU1
     ----                    ----
 lock(sb_pagefaults);
                             lock(&mm->mmap_lock#2);
                             lock(sb_pagefaults);
 lock(&fs_info->reloc_mutex);

 *** DEADLOCK ***

3 locks held by systemd-journal/509:
 #0: ffff97083bdec8b8 (&mm->mmap_lock#2){++++}-{3:3}, at: do_user_addr_fault+0x12e/0x4b0
 #1: ffff97083144d598 (sb_pagefaults){.+.+}-{0:0}, at: btrfs_page_mkwrite+0x59/0x560 [btrfs]
 #2: ffff97083144d6a8 (sb_internal){.+.+}-{0:0}, at: start_transaction+0x3f8/0x500 [btrfs]

stack backtrace:
CPU: 0 PID: 509 Comm: systemd-journal Not tainted 5.8.0-0.rc3.1.fc33.x86_64+debug #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
Call Trace:
 dump_stack+0x92/0xc8
 check_noncircular+0x134/0x150
 __lock_acquire+0x1241/0x20c0
 lock_acquire+0xb0/0x400
 ? btrfs_record_root_in_trans+0x44/0x70 [btrfs]
 ? lock_acquire+0xb0/0x400
 ? btrfs_record_root_in_trans+0x44/0x70 [btrfs]
 __mutex_lock+0x7b/0x820
 ? btrfs_record_root_in_trans+0x44/0x70 [btrfs]
 ? kvm_sched_clock_read+0x14/0x30
 ? sched_clock+0x5/0x10
 ? sched_clock_cpu+0xc/0xb0
 btrfs_record_root_in_trans+0x44/0x70 [btrfs]
 start_transaction+0xd2/0x500 [btrfs]
 btrfs_dirty_inode+0x44/0xd0 [btrfs]
 file_update_time+0xc6/0x120
 btrfs_page_mkwrite+0xda/0x560 [btrfs]
 ? sched_clock+0x5/0x10
 do_page_mkwrite+0x4f/0x130
 do_wp_page+0x3b0/0x4f0
 handle_mm_fault+0xf47/0x1850
 do_user_addr_fault+0x1fc/0x4b0
 exc_page_fault+0x88/0x300
 ? asm_exc_page_fault+0x8/0x30
 asm_exc_page_fault+0x1e/0x30
RIP: 0033:0x7fa3972fdbfe
Code: Bad RIP value.

Fix this by not holding the ->device_list_mutex at this point.  The
device_list_mutex exists to protect us from modifying the device list
while the file system is running.

However it can also be modified by doing a scan on a device.  But this
action is specifically protected by the uuid_mutex, which we are holding
here.  We cannot race with opening at this point because we have the
->s_mount lock held during the mount.  Not having the
->device_list_mutex here is perfectly safe as we're not going to change
the devices at this point.

CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add some comments ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21 11:05:30 +02:00
Anand Jain
fa51195469 btrfs: don't traverse into the seed devices in show_devname
commit 4faf55b03823e96c44dc4e364520000ed3b12fdb upstream.

->show_devname currently shows the lowest devid in the list. As the seed
devices have the lowest devid in the sprouted filesystem, the userland
tool such as findmnt end up seeing seed device instead of the device from
the read-writable sprouted filesystem. As shown below.

 mount /dev/sda /btrfs
 mount: /btrfs: WARNING: device write-protected, mounted read-only.

 findmnt --output SOURCE,TARGET,UUID /btrfs
 SOURCE   TARGET UUID
 /dev/sda /btrfs 899f7027-3e46-4626-93e7-7d4c9ad19111

 btrfs dev add -f /dev/sdb /btrfs

 umount /btrfs
 mount /dev/sdb /btrfs

 findmnt --output SOURCE,TARGET,UUID /btrfs
 SOURCE   TARGET UUID
 /dev/sda /btrfs 899f7027-3e46-4626-93e7-7d4c9ad19111

All sprouts from a single seed will show the same seed device and the
same fsid. That's confusing.
This is causing problems in our prototype as there isn't any reference
to the sprout file-system(s) which is being used for actual read and
write.

This was added in the patch which implemented the show_devname in btrfs
commit 9c5085c147 ("Btrfs: implement ->show_devname").
I tried to look for any particular reason that we need to show the seed
device, there isn't any.

So instead, do not traverse through the seed devices, just show the
lowest devid in the sprouted fsid.

After the patch:

 mount /dev/sda /btrfs
 mount: /btrfs: WARNING: device write-protected, mounted read-only.

 findmnt --output SOURCE,TARGET,UUID /btrfs
 SOURCE   TARGET UUID
 /dev/sda /btrfs 899f7027-3e46-4626-93e7-7d4c9ad19111

 btrfs dev add -f /dev/sdb /btrfs
 mount -o rw,remount /dev/sdb /btrfs

 findmnt --output SOURCE,TARGET,UUID /btrfs
 SOURCE   TARGET UUID
 /dev/sdb /btrfs 595ca0e6-b82e-46b5-b9e2-c72a6928be48

 mount /dev/sda /btrfs1
 mount: /btrfs1: WARNING: device write-protected, mounted read-only.

 btrfs dev add -f /dev/sdc /btrfs1

 findmnt --output SOURCE,TARGET,UUID /btrfs1
 SOURCE   TARGET  UUID
 /dev/sdc /btrfs1 ca1dbb7a-8446-4f95-853c-a20f3f82bdbb

 cat /proc/self/mounts | grep btrfs
 /dev/sdb /btrfs btrfs rw,relatime,noacl,space_cache,subvolid=5,subvol=/ 0 0
 /dev/sdc /btrfs1 btrfs ro,relatime,noacl,space_cache,subvolid=5,subvol=/ 0 0

Reported-by: Martin K. Petersen <martin.petersen@oracle.com>
CC: stable@vger.kernel.org # 4.19+
Tested-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21 11:05:30 +02:00