52540 Commits

Author SHA1 Message Date
Josef Bacik
0eaf383c6a btrfs: do not BUG_ON in link_to_fixup_dir
[ Upstream commit 91df99a6eb50d5a1bc70fff4a09a0b7ae6aab96d ]

While doing error injection testing I got the following panic

  kernel BUG at fs/btrfs/tree-log.c:1862!
  invalid opcode: 0000 [#1] SMP NOPTI
  CPU: 1 PID: 7836 Comm: mount Not tainted 5.13.0-rc1+ #305
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
  RIP: 0010:link_to_fixup_dir+0xd5/0xe0
  RSP: 0018:ffffb5800180fa30 EFLAGS: 00010216
  RAX: fffffffffffffffb RBX: 00000000fffffffb RCX: ffff8f595287faf0
  RDX: ffffb5800180fa37 RSI: ffff8f5954978800 RDI: 0000000000000000
  RBP: ffff8f5953af9450 R08: 0000000000000019 R09: 0000000000000001
  R10: 000151f408682970 R11: 0000000120021001 R12: ffff8f5954978800
  R13: ffff8f595287faf0 R14: ffff8f5953c77dd0 R15: 0000000000000065
  FS:  00007fc5284c8c40(0000) GS:ffff8f59bbd00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007fc5287f47c0 CR3: 000000011275e002 CR4: 0000000000370ee0
  Call Trace:
   replay_one_buffer+0x409/0x470
   ? btree_read_extent_buffer_pages+0xd0/0x110
   walk_up_log_tree+0x157/0x1e0
   walk_log_tree+0xa6/0x1d0
   btrfs_recover_log_trees+0x1da/0x360
   ? replay_one_extent+0x7b0/0x7b0
   open_ctree+0x1486/0x1720
   btrfs_mount_root.cold+0x12/0xea
   ? __kmalloc_track_caller+0x12f/0x240
   legacy_get_tree+0x24/0x40
   vfs_get_tree+0x22/0xb0
   vfs_kern_mount.part.0+0x71/0xb0
   btrfs_mount+0x10d/0x380
   ? vfs_parse_fs_string+0x4d/0x90
   legacy_get_tree+0x24/0x40
   vfs_get_tree+0x22/0xb0
   path_mount+0x433/0xa10
   __x64_sys_mount+0xe3/0x120
   do_syscall_64+0x3d/0x80
   entry_SYSCALL_64_after_hwframe+0x44/0xae

We can get -EIO or any number of legitimate errors from
btrfs_search_slot(), panicing here is not the appropriate response.  The
error path for this code handles errors properly, simply return the
error.

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>
2021-06-03 08:36:22 +02:00
Zhang Xiaoxu
ce20dd9172 NFSv4: Fix v4.0/v4.1 SEEK_DATA return -ENOTSUPP when set NFS_V4_2 config
commit e67afa7ee4a59584d7253e45d7f63b9528819a13 upstream.

Since commit bdcc2cd14e4e ("NFSv4.2: handle NFS-specific llseek errors"),
nfs42_proc_llseek would return -EOPNOTSUPP rather than -ENOTSUPP when
SEEK_DATA on NFSv4.0/v4.1.

This will lead xfstests generic/285 not run on NFSv4.0/v4.1 when set the
CONFIG_NFS_V4_2, rather than run failed.

Fixes: bdcc2cd14e4e ("NFSv4.2: handle NFS-specific llseek errors")
Cc: <stable.vger.kernel.org> # 4.2
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-03 08:36:18 +02:00
Trond Myklebust
c757c1f1e6 NFS: Don't corrupt the value of pg_bytes_written in nfs_do_recoalesce()
commit 0d0ea309357dea0d85a82815f02157eb7fcda39f upstream.

The value of mirror->pg_bytes_written should only be updated after a
successful attempt to flush out the requests on the list.

Fixes: a7d42ddb3099 ("nfs: add mirroring support to pgio layer")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-03 08:36:18 +02:00
Dan Carpenter
f299522eda NFS: fix an incorrect limit in filelayout_decode_layout()
commit 769b01ea68b6c49dc3cde6adf7e53927dacbd3a8 upstream.

The "sizeof(struct nfs_fh)" is two bytes too large and could lead to
memory corruption.  It should be NFS_MAXFHSIZE because that's the size
of the ->data[] buffer.

I reversed the size of the arguments to put the variable on the left.

Fixes: 16b374ca439f ("NFSv4.1: pnfs: filelayout: add driver's LAYOUTGET and GETDEVICEINFO infrastructure")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-03 08:36:18 +02:00
Kees Cook
72bd26a791 proc: Check /proc/$pid/attr/ writes against file opener
commit bfb819ea20ce8bbeeba17e1a6418bf8bda91fc28 upstream.

Fix another "confused deputy" weakness[1]. Writes to /proc/$pid/attr/
files need to check the opener credentials, since these fds do not
transition state across execve(). Without this, it is possible to
trick another process (which may have different credentials) to write
to its own /proc/$pid/attr/ files, leading to unexpected and possibly
exploitable behaviors.

[1] https://www.kernel.org/doc/html/latest/security/credentials.html?highlight=confused#open-file-credentials

Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-03 08:36:12 +02:00
Anna Schumaker
42637ca25c NFSv4: Fix a NULL pointer dereference in pnfs_mark_matching_lsegs_return()
commit a421d218603ffa822a0b8045055c03eae394a7eb upstream.

Commit de144ff4234f changes _pnfs_return_layout() to call
pnfs_mark_matching_lsegs_return() passing NULL as the struct
pnfs_layout_range argument. Unfortunately,
pnfs_mark_matching_lsegs_return() doesn't check if we have a value here
before dereferencing it, causing an oops.

I'm able to hit this crash consistently when running connectathon basic
tests on NFS v4.1/v4.2 against Ontap.

Fixes: de144ff4234f ("NFSv4: Don't discard segments marked for return in _pnfs_return_layout()")
Cc: stable@vger.kernel.org
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-03 08:36:12 +02:00
Greg Kroah-Hartman
0da29c155f Revert "ecryptfs: replace BUG_ON with error handling code"
commit e1436df2f2550bc89d832ffd456373fdf5d5b5d7 upstream.

This reverts commit 2c2a7552dd6465e8fde6bc9cccf8d66ed1c1eb72.

Because of recent interactions with developers from @umn.edu, all
commits from them have been recently re-reviewed to ensure if they were
correct or not.

Upon review, this commit was found to be incorrect for the reasons
below, so it must be reverted.  It will be fixed up "correctly" in a
later kernel change.

The original commit log for this change was incorrect, no "error
handling code" was added, things will blow up just as badly as before if
any of these cases ever were true.  As this BUG_ON() never fired, and
most of these checks are "obviously" never going to be true, let's just
revert to the original code for now until this gets unwound to be done
correctly in the future.

Cc: Aditya Pakki <pakki001@umn.edu>
Fixes: 2c2a7552dd64 ("ecryptfs: replace BUG_ON with error handling code")
Cc: stable <stable@vger.kernel.org>
Acked-by: Tyler Hicks <code@tyhicks.com>
Link: https://lore.kernel.org/r/20210503115736.2104747-49-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-26 11:47:00 +02:00
Ronnie Sahlberg
a093626069 cifs: fix memory leak in smb2_copychunk_range
commit d201d7631ca170b038e7f8921120d05eec70d7c5 upstream.

When using smb2_copychunk_range() for large ranges we will
run through several iterations of a loop calling SMB2_ioctl()
but never actually free the returned buffer except for the final
iteration.
This leads to memory leaks everytime a large copychunk is requested.

Fixes: 9bf0c9cd4314 ("CIFS: Fix SMB2/SMB3 Copy offload support (refcopy) for large files")
Cc: <stable@vger.kernel.org>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-26 11:46:58 +02:00
yangerkun
dcc9d34254 block: reexpand iov_iter after read/write
[ Upstream commit cf7b39a0cbf6bf57aa07a008d46cf695add05b4c ]

We get a bug:

BUG: KASAN: slab-out-of-bounds in iov_iter_revert+0x11c/0x404
lib/iov_iter.c:1139
Read of size 8 at addr ffff0000d3fb11f8 by task

CPU: 0 PID: 12582 Comm: syz-executor.2 Not tainted
5.10.0-00843-g352c8610ccd2 #2
Hardware name: linux,dummy-virt (DT)
Call trace:
 dump_backtrace+0x0/0x2d0 arch/arm64/kernel/stacktrace.c:132
 show_stack+0x28/0x34 arch/arm64/kernel/stacktrace.c:196
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x110/0x164 lib/dump_stack.c:118
 print_address_description+0x78/0x5c8 mm/kasan/report.c:385
 __kasan_report mm/kasan/report.c:545 [inline]
 kasan_report+0x148/0x1e4 mm/kasan/report.c:562
 check_memory_region_inline mm/kasan/generic.c:183 [inline]
 __asan_load8+0xb4/0xbc mm/kasan/generic.c:252
 iov_iter_revert+0x11c/0x404 lib/iov_iter.c:1139
 io_read fs/io_uring.c:3421 [inline]
 io_issue_sqe+0x2344/0x2d64 fs/io_uring.c:5943
 __io_queue_sqe+0x19c/0x520 fs/io_uring.c:6260
 io_queue_sqe+0x2a4/0x590 fs/io_uring.c:6326
 io_submit_sqe fs/io_uring.c:6395 [inline]
 io_submit_sqes+0x4c0/0xa04 fs/io_uring.c:6624
 __do_sys_io_uring_enter fs/io_uring.c:9013 [inline]
 __se_sys_io_uring_enter fs/io_uring.c:8960 [inline]
 __arm64_sys_io_uring_enter+0x190/0x708 fs/io_uring.c:8960
 __invoke_syscall arch/arm64/kernel/syscall.c:36 [inline]
 invoke_syscall arch/arm64/kernel/syscall.c:48 [inline]
 el0_svc_common arch/arm64/kernel/syscall.c:158 [inline]
 do_el0_svc+0x120/0x290 arch/arm64/kernel/syscall.c:227
 el0_svc+0x1c/0x28 arch/arm64/kernel/entry-common.c:367
 el0_sync_handler+0x98/0x170 arch/arm64/kernel/entry-common.c:383
 el0_sync+0x140/0x180 arch/arm64/kernel/entry.S:670

Allocated by task 12570:
 stack_trace_save+0x80/0xb8 kernel/stacktrace.c:121
 kasan_save_stack mm/kasan/common.c:48 [inline]
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc+0xdc/0x120 mm/kasan/common.c:461
 kasan_kmalloc+0xc/0x14 mm/kasan/common.c:475
 __kmalloc+0x23c/0x334 mm/slub.c:3970
 kmalloc include/linux/slab.h:557 [inline]
 __io_alloc_async_data+0x68/0x9c fs/io_uring.c:3210
 io_setup_async_rw fs/io_uring.c:3229 [inline]
 io_read fs/io_uring.c:3436 [inline]
 io_issue_sqe+0x2954/0x2d64 fs/io_uring.c:5943
 __io_queue_sqe+0x19c/0x520 fs/io_uring.c:6260
 io_queue_sqe+0x2a4/0x590 fs/io_uring.c:6326
 io_submit_sqe fs/io_uring.c:6395 [inline]
 io_submit_sqes+0x4c0/0xa04 fs/io_uring.c:6624
 __do_sys_io_uring_enter fs/io_uring.c:9013 [inline]
 __se_sys_io_uring_enter fs/io_uring.c:8960 [inline]
 __arm64_sys_io_uring_enter+0x190/0x708 fs/io_uring.c:8960
 __invoke_syscall arch/arm64/kernel/syscall.c:36 [inline]
 invoke_syscall arch/arm64/kernel/syscall.c:48 [inline]
 el0_svc_common arch/arm64/kernel/syscall.c:158 [inline]
 do_el0_svc+0x120/0x290 arch/arm64/kernel/syscall.c:227
 el0_svc+0x1c/0x28 arch/arm64/kernel/entry-common.c:367
 el0_sync_handler+0x98/0x170 arch/arm64/kernel/entry-common.c:383
 el0_sync+0x140/0x180 arch/arm64/kernel/entry.S:670

Freed by task 12570:
 stack_trace_save+0x80/0xb8 kernel/stacktrace.c:121
 kasan_save_stack mm/kasan/common.c:48 [inline]
 kasan_set_track+0x38/0x6c mm/kasan/common.c:56
 kasan_set_free_info+0x20/0x40 mm/kasan/generic.c:355
 __kasan_slab_free+0x124/0x150 mm/kasan/common.c:422
 kasan_slab_free+0x10/0x1c mm/kasan/common.c:431
 slab_free_hook mm/slub.c:1544 [inline]
 slab_free_freelist_hook mm/slub.c:1577 [inline]
 slab_free mm/slub.c:3142 [inline]
 kfree+0x104/0x38c mm/slub.c:4124
 io_dismantle_req fs/io_uring.c:1855 [inline]
 __io_free_req+0x70/0x254 fs/io_uring.c:1867
 io_put_req_find_next fs/io_uring.c:2173 [inline]
 __io_queue_sqe+0x1fc/0x520 fs/io_uring.c:6279
 __io_req_task_submit+0x154/0x21c fs/io_uring.c:2051
 io_req_task_submit+0x2c/0x44 fs/io_uring.c:2063
 task_work_run+0xdc/0x128 kernel/task_work.c:151
 get_signal+0x6f8/0x980 kernel/signal.c:2562
 do_signal+0x108/0x3a4 arch/arm64/kernel/signal.c:658
 do_notify_resume+0xbc/0x25c arch/arm64/kernel/signal.c:722
 work_pending+0xc/0x180

blkdev_read_iter can truncate iov_iter's count since the count + pos may
exceed the size of the blkdev. This will confuse io_read that we have
consume the iovec. And once we do the iov_iter_revert in io_read, we
will trigger the slab-out-of-bounds. Fix it by reexpand the count with
size has been truncated.

blkdev_write_iter can trigger the problem too.

Signed-off-by: yangerkun <yangerkun@huawei.com>
Acked-by: Pavel Begunkov <asml.silencec@gmail.com>
Link: https://lore.kernel.org/r/20210401071807.3328235-1-yangerkun@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-22 10:57:43 +02:00
Jeff Layton
2c652bda76 ceph: fix fscache invalidation
[ Upstream commit 10a7052c7868bc7bc72d947f5aac6f768928db87 ]

Ensure that we invalidate the fscache whenever we invalidate the
pagecache.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-22 10:57:42 +02:00
Phillip Lougher
1eafadd100 squashfs: fix divide error in calculate_skip()
commit d6e621de1fceb3b098ebf435ef7ea91ec4838a1a upstream.

Sysbot has reported a "divide error" which has been identified as being
caused by a corrupted file_size value within the file inode.  This value
has been corrupted to a much larger value than expected.

Calculate_skip() is passed i_size_read(inode) >> msblk->block_log.  Due to
the file_size value corruption this overflows the int argument/variable in
that function, leading to the divide error.

This patch changes the function to use u64.  This will accommodate any
unexpectedly large values due to corruption.

The value returned from calculate_skip() is clamped to be never more than
SQUASHFS_CACHED_BLKS - 1, or 7.  So file_size corruption does not lead to
an unexpectedly large return result here.

Link: https://lkml.kernel.org/r/20210507152618.9447-1-phillip@squashfs.org.uk
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Reported-by: <syzbot+e8f781243ce16ac2f962@syzkaller.appspotmail.com>
Reported-by: <syzbot+7b98870d4fec9447b951@syzkaller.appspotmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22 10:57:39 +02:00
Olga Kornievskaia
0e28999866 NFSv4.2 fix handling of sr_eof in SEEK's reply
[ Upstream commit 73f5c88f521a630ea1628beb9c2d48a2e777a419 ]

Currently the client ignores the value of the sr_eof of the SEEK
operation. According to the spec, if the server didn't find the
requested extent and reached the end of the file, the server
would return sr_eof=true. In case the request for DATA and no
data was found (ie in the middle of the hole), then the lseek
expects that ENXIO would be returned.

Fixes: 1c6dcbe5ceff8 ("NFS: Implement SEEK")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-22 10:57:38 +02:00
Nikola Livic
40286f0852 pNFS/flexfiles: fix incorrect size check in decode_nfs_fh()
[ Upstream commit ed34695e15aba74f45247f1ee2cf7e09d449f925 ]

We (adam zabrocki, alexander matrosov, alexander tereshkin, maksym
bazalii) observed the check:

	if (fh->size > sizeof(struct nfs_fh))

should not use the size of the nfs_fh struct which includes an extra two
bytes from the size field.

struct nfs_fh {
	unsigned short         size;
	unsigned char          data[NFS_MAXFHSIZE];
}

but should determine the size from data[NFS_MAXFHSIZE] so the memcpy
will not write 2 bytes beyond destination.  The proposed fix is to
compare against the NFS_MAXFHSIZE directly, as is done elsewhere in fs
code base.

Fixes: d67ae825a59d ("pnfs/flexfiles: Add the FlexFile Layout Driver")
Signed-off-by: Nikola Livic <nlivic@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-22 10:57:38 +02:00
Trond Myklebust
ca0723209f NFS: Deal correctly with attribute generation counter overflow
[ Upstream commit 9fdbfad1777cb4638f489eeb62d85432010c0031 ]

We need to use unsigned long subtraction and then convert to signed in
order to deal correcly with C overflow rules.

Fixes: f5062003465c ("NFS: Set an attribute barrier on all updates")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-22 10:57:38 +02:00
Trond Myklebust
37db850878 NFSv4.2: Always flush out writes in nfs42_proc_fallocate()
[ Upstream commit 99f23783224355e7022ceea9b8d9f62c0fd01bd8 ]

Whether we're allocating or delallocating space, we should flush out the
pending writes in order to avoid races with attribute updates.

Fixes: 1e564d3dbd68 ("NFSv4.2: Fix a race in nfs42_proc_deallocate()")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-22 10:57:38 +02:00
Colin Ian King
769171e21c f2fs: fix a redundant call to f2fs_balance_fs if an error occurs
[ Upstream commit 28e18ee636ba28532dbe425540af06245a0bbecb ]

The  uninitialized variable dn.node_changed does not get set when a
call to f2fs_get_node_page fails.  This uninitialized value gets used
in the call to f2fs_balance_fs() that may or not may not balances
dirty node and dentry pages depending on the uninitialized state of
the variable. Fix this by only calling f2fs_balance_fs if err is
not set.

Thanks to Jaegeuk Kim for suggesting an appropriate fix.

Addresses-Coverity: ("Uninitialized scalar variable")
Fixes: 2a3407607028 ("f2fs: call f2fs_balance_fs only when node was changed")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-22 10:57:38 +02:00
Miklos Szeredi
c085fceceb cuse: prevent clone
[ Upstream commit 8217673d07256b22881127bf50dce874d0e51653 ]

For cloned connections cuse_channel_release() will be called more than
once, resulting in use after free.

Prevent device cloning for CUSE, which does not make sense at this point,
and highly unlikely to be used in real life.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-22 10:57:36 +02:00
Alexander Aring
b0523c32a0 fs: dlm: fix debugfs dump
[ Upstream commit 92c48950b43f4a767388cf87709d8687151a641f ]

This patch fixes the following message which randomly pops up during
glocktop call:

seq_file: buggy .next function table_seq_next did not update position index

The issue is that seq_read_iter() in fs/seq_file.c also needs an
increment of the index in an non next record case as well which this
patch fixes otherwise seq_read_iter() will print out the above message.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-22 10:57:35 +02:00
Fengnan Chang
5a480aeb8b ext4: fix error code in ext4_commit_super
commit f88f1466e2a2e5ca17dfada436d3efa1b03a3972 upstream.

We should set the error code when ext4_commit_super check argument failed.
Found in code review.
Fixes: c4be0c1dc4cdc ("filesystem freeze: add error handling of write_super_lockfs/unlockfs").

Cc: stable@kernel.org
Signed-off-by: Fengnan Chang <changfengnan@vivo.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/20210402101631.561-1-changfengnan@vivo.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22 10:57:22 +02:00
Zhang Yi
e70db6e432 ext4: fix check to prevent false positive report of incorrect used inodes
commit a149d2a5cabbf6507a7832a1c4fd2593c55fd450 upstream.

Commit <50122847007> ("ext4: fix check to prevent initializing reserved
inodes") check the block group zero and prevent initializing reserved
inodes. But in some special cases, the reserved inode may not all belong
to the group zero, it may exist into the second group if we format
filesystem below.

  mkfs.ext4 -b 4096 -g 8192 -N 1024 -I 4096 /dev/sda

So, it will end up triggering a false positive report of a corrupted
file system. This patch fix it by avoid check reserved inodes if no free
inode blocks will be zeroed.

Cc: stable@kernel.org
Fixes: 50122847007 ("ext4: fix check to prevent initializing reserved inodes")
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Suggested-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210331121516.2243099-1-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22 10:57:22 +02:00
Yang Yang
7d1044c19d jffs2: check the validity of dstlen in jffs2_zlib_compress()
commit 90ada91f4610c5ef11bc52576516d96c496fc3f1 upstream.

KASAN reports a BUG when download file in jffs2 filesystem.It is
because when dstlen == 1, cpage_out will write array out of bounds.
Actually, data will not be compressed in jffs2_zlib_compress() if
data's length less than 4.

[  393.799778] BUG: KASAN: slab-out-of-bounds in jffs2_rtime_compress+0x214/0x2f0 at addr ffff800062e3b281
[  393.809166] Write of size 1 by task tftp/2918
[  393.813526] CPU: 3 PID: 2918 Comm: tftp Tainted: G    B           4.9.115-rt93-EMBSYS-CGEL-6.1.R6-dirty #1
[  393.823173] Hardware name: LS1043A RDB Board (DT)
[  393.827870] Call trace:
[  393.830322] [<ffff20000808c700>] dump_backtrace+0x0/0x2f0
[  393.835721] [<ffff20000808ca04>] show_stack+0x14/0x20
[  393.840774] [<ffff2000086ef700>] dump_stack+0x90/0xb0
[  393.845829] [<ffff20000827b19c>] kasan_object_err+0x24/0x80
[  393.851402] [<ffff20000827b404>] kasan_report_error+0x1b4/0x4d8
[  393.857323] [<ffff20000827bae8>] kasan_report+0x38/0x40
[  393.862548] [<ffff200008279d44>] __asan_store1+0x4c/0x58
[  393.867859] [<ffff2000084ce2ec>] jffs2_rtime_compress+0x214/0x2f0
[  393.873955] [<ffff2000084bb3b0>] jffs2_selected_compress+0x178/0x2a0
[  393.880308] [<ffff2000084bb530>] jffs2_compress+0x58/0x478
[  393.885796] [<ffff2000084c5b34>] jffs2_write_inode_range+0x13c/0x450
[  393.892150] [<ffff2000084be0b8>] jffs2_write_end+0x2a8/0x4a0
[  393.897811] [<ffff2000081f3008>] generic_perform_write+0x1c0/0x280
[  393.903990] [<ffff2000081f5074>] __generic_file_write_iter+0x1c4/0x228
[  393.910517] [<ffff2000081f5210>] generic_file_write_iter+0x138/0x288
[  393.916870] [<ffff20000829ec1c>] __vfs_write+0x1b4/0x238
[  393.922181] [<ffff20000829ff00>] vfs_write+0xd0/0x238
[  393.927232] [<ffff2000082a1ba8>] SyS_write+0xa0/0x110
[  393.932283] [<ffff20000808429c>] __sys_trace_return+0x0/0x4
[  393.937851] Object at ffff800062e3b280, in cache kmalloc-64 size: 64
[  393.944197] Allocated:
[  393.946552] PID = 2918
[  393.948913]  save_stack_trace_tsk+0x0/0x220
[  393.953096]  save_stack_trace+0x18/0x20
[  393.956932]  kasan_kmalloc+0xd8/0x188
[  393.960594]  __kmalloc+0x144/0x238
[  393.963994]  jffs2_selected_compress+0x48/0x2a0
[  393.968524]  jffs2_compress+0x58/0x478
[  393.972273]  jffs2_write_inode_range+0x13c/0x450
[  393.976889]  jffs2_write_end+0x2a8/0x4a0
[  393.980810]  generic_perform_write+0x1c0/0x280
[  393.985251]  __generic_file_write_iter+0x1c4/0x228
[  393.990040]  generic_file_write_iter+0x138/0x288
[  393.994655]  __vfs_write+0x1b4/0x238
[  393.998228]  vfs_write+0xd0/0x238
[  394.001543]  SyS_write+0xa0/0x110
[  394.004856]  __sys_trace_return+0x0/0x4
[  394.008684] Freed:
[  394.010691] PID = 2918
[  394.013051]  save_stack_trace_tsk+0x0/0x220
[  394.017233]  save_stack_trace+0x18/0x20
[  394.021069]  kasan_slab_free+0x88/0x188
[  394.024902]  kfree+0x6c/0x1d8
[  394.027868]  jffs2_sum_write_sumnode+0x2c4/0x880
[  394.032486]  jffs2_do_reserve_space+0x198/0x598
[  394.037016]  jffs2_reserve_space+0x3f8/0x4d8
[  394.041286]  jffs2_write_inode_range+0xf0/0x450
[  394.045816]  jffs2_write_end+0x2a8/0x4a0
[  394.049737]  generic_perform_write+0x1c0/0x280
[  394.054179]  __generic_file_write_iter+0x1c4/0x228
[  394.058968]  generic_file_write_iter+0x138/0x288
[  394.063583]  __vfs_write+0x1b4/0x238
[  394.067157]  vfs_write+0xd0/0x238
[  394.070470]  SyS_write+0xa0/0x110
[  394.073783]  __sys_trace_return+0x0/0x4
[  394.077612] Memory state around the buggy address:
[  394.082404]  ffff800062e3b180: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
[  394.089623]  ffff800062e3b200: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
[  394.096842] >ffff800062e3b280: 01 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  394.104056]                    ^
[  394.107283]  ffff800062e3b300: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
[  394.114502]  ffff800062e3b380: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
[  394.121718] ==================================================================

Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>
Cc: Joel Stanley <joel@jms.id.au>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22 10:57:22 +02:00
lizhe
f971e69fea jffs2: Fix kasan slab-out-of-bounds problem
commit 960b9a8a7676b9054d8b46a2c7db52a0c8766b56 upstream.

KASAN report a slab-out-of-bounds problem. The logs are listed below.
It is because in function jffs2_scan_dirent_node, we alloc "checkedlen+1"
bytes for fd->name and we check crc with length rd->nsize. If checkedlen
is less than rd->nsize, it will cause the slab-out-of-bounds problem.

jffs2: Dirent at *** has zeroes in name. Truncating to %d char
==================================================================
BUG: KASAN: slab-out-of-bounds in crc32_le+0x1ce/0x260 at addr ffff8800842cf2d1
Read of size 1 by task test_JFFS2/915
=============================================================================
BUG kmalloc-64 (Tainted: G    B      O   ): kasan: bad access detected
-----------------------------------------------------------------------------
INFO: Allocated in jffs2_alloc_full_dirent+0x2a/0x40 age=0 cpu=1 pid=915
	___slab_alloc+0x580/0x5f0
	__slab_alloc.isra.24+0x4e/0x64
	__kmalloc+0x170/0x300
	jffs2_alloc_full_dirent+0x2a/0x40
	jffs2_scan_eraseblock+0x1ca4/0x3b64
	jffs2_scan_medium+0x285/0xfe0
	jffs2_do_mount_fs+0x5fb/0x1bbc
	jffs2_do_fill_super+0x245/0x6f0
	jffs2_fill_super+0x287/0x2e0
	mount_mtd_aux.isra.0+0x9a/0x144
	mount_mtd+0x222/0x2f0
	jffs2_mount+0x41/0x60
	mount_fs+0x63/0x230
	vfs_kern_mount.part.6+0x6c/0x1f4
	do_mount+0xae8/0x1940
	SyS_mount+0x105/0x1d0
INFO: Freed in jffs2_free_full_dirent+0x22/0x40 age=27 cpu=1 pid=915
	__slab_free+0x372/0x4e4
	kfree+0x1d4/0x20c
	jffs2_free_full_dirent+0x22/0x40
	jffs2_build_remove_unlinked_inode+0x17a/0x1e4
	jffs2_do_mount_fs+0x1646/0x1bbc
	jffs2_do_fill_super+0x245/0x6f0
	jffs2_fill_super+0x287/0x2e0
	mount_mtd_aux.isra.0+0x9a/0x144
	mount_mtd+0x222/0x2f0
	jffs2_mount+0x41/0x60
	mount_fs+0x63/0x230
	vfs_kern_mount.part.6+0x6c/0x1f4
	do_mount+0xae8/0x1940
	SyS_mount+0x105/0x1d0
	entry_SYSCALL_64_fastpath+0x1e/0x97
Call Trace:
 [<ffffffff815befef>] dump_stack+0x59/0x7e
 [<ffffffff812d1d65>] print_trailer+0x125/0x1b0
 [<ffffffff812d82c8>] object_err+0x34/0x40
 [<ffffffff812dadef>] kasan_report.part.1+0x21f/0x534
 [<ffffffff81132401>] ? vprintk+0x2d/0x40
 [<ffffffff815f1ee2>] ? crc32_le+0x1ce/0x260
 [<ffffffff812db41a>] kasan_report+0x26/0x30
 [<ffffffff812d9fc1>] __asan_load1+0x3d/0x50
 [<ffffffff815f1ee2>] crc32_le+0x1ce/0x260
 [<ffffffff814764ae>] ? jffs2_alloc_full_dirent+0x2a/0x40
 [<ffffffff81485cec>] jffs2_scan_eraseblock+0x1d0c/0x3b64
 [<ffffffff81488813>] ? jffs2_scan_medium+0xccf/0xfe0
 [<ffffffff81483fe0>] ? jffs2_scan_make_ino_cache+0x14c/0x14c
 [<ffffffff812da3e9>] ? kasan_unpoison_shadow+0x35/0x50
 [<ffffffff812da3e9>] ? kasan_unpoison_shadow+0x35/0x50
 [<ffffffff812da462>] ? kasan_kmalloc+0x5e/0x70
 [<ffffffff812d5d90>] ? kmem_cache_alloc_trace+0x10c/0x2cc
 [<ffffffff818169fb>] ? mtd_point+0xf7/0x130
 [<ffffffff81487dc9>] jffs2_scan_medium+0x285/0xfe0
 [<ffffffff81487b44>] ? jffs2_scan_eraseblock+0x3b64/0x3b64
 [<ffffffff812da3e9>] ? kasan_unpoison_shadow+0x35/0x50
 [<ffffffff812da3e9>] ? kasan_unpoison_shadow+0x35/0x50
 [<ffffffff812da462>] ? kasan_kmalloc+0x5e/0x70
 [<ffffffff812d57df>] ? __kmalloc+0x12b/0x300
 [<ffffffff812da462>] ? kasan_kmalloc+0x5e/0x70
 [<ffffffff814a2753>] ? jffs2_sum_init+0x9f/0x240
 [<ffffffff8148b2ff>] jffs2_do_mount_fs+0x5fb/0x1bbc
 [<ffffffff8148ad04>] ? jffs2_del_noinode_dirent+0x640/0x640
 [<ffffffff812da462>] ? kasan_kmalloc+0x5e/0x70
 [<ffffffff81127c5b>] ? __init_rwsem+0x97/0xac
 [<ffffffff81492349>] jffs2_do_fill_super+0x245/0x6f0
 [<ffffffff81493c5b>] jffs2_fill_super+0x287/0x2e0
 [<ffffffff814939d4>] ? jffs2_parse_options+0x594/0x594
 [<ffffffff81819bea>] mount_mtd_aux.isra.0+0x9a/0x144
 [<ffffffff81819eb6>] mount_mtd+0x222/0x2f0
 [<ffffffff814939d4>] ? jffs2_parse_options+0x594/0x594
 [<ffffffff81819c94>] ? mount_mtd_aux.isra.0+0x144/0x144
 [<ffffffff81258757>] ? free_pages+0x13/0x1c
 [<ffffffff814fa0ac>] ? selinux_sb_copy_data+0x278/0x2e0
 [<ffffffff81492b35>] jffs2_mount+0x41/0x60
 [<ffffffff81302fb7>] mount_fs+0x63/0x230
 [<ffffffff8133755f>] ? alloc_vfsmnt+0x32f/0x3b0
 [<ffffffff81337f2c>] vfs_kern_mount.part.6+0x6c/0x1f4
 [<ffffffff8133ceec>] do_mount+0xae8/0x1940
 [<ffffffff811b94e0>] ? audit_filter_rules.constprop.6+0x1d10/0x1d10
 [<ffffffff8133c404>] ? copy_mount_string+0x40/0x40
 [<ffffffff812cbf78>] ? alloc_pages_current+0xa4/0x1bc
 [<ffffffff81253a89>] ? __get_free_pages+0x25/0x50
 [<ffffffff81338993>] ? copy_mount_options.part.17+0x183/0x264
 [<ffffffff8133e3a9>] SyS_mount+0x105/0x1d0
 [<ffffffff8133e2a4>] ? copy_mnt_ns+0x560/0x560
 [<ffffffff810e8391>] ? msa_space_switch_handler+0x13d/0x190
 [<ffffffff81be184a>] entry_SYSCALL_64_fastpath+0x1e/0x97
 [<ffffffff810e9274>] ? msa_space_switch+0xb0/0xe0
Memory state around the buggy address:
 ffff8800842cf180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8800842cf200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8800842cf280: fc fc fc fc fc fc 00 00 00 00 01 fc fc fc fc fc
                                                 ^
 ffff8800842cf300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8800842cf380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Cc: stable@vger.kernel.org
Reported-by: Kunkun Xu <xukunkun1@huawei.com>
Signed-off-by: lizhe <lizhe67@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22 10:57:21 +02:00
Trond Myklebust
7b7b977464 NFSv4: Don't discard segments marked for return in _pnfs_return_layout()
commit de144ff4234f935bd2150108019b5d87a90a8a96 upstream.

If the pNFS layout segment is marked with the NFS_LSEG_LAYOUTRETURN
flag, then the assumption is that it has some reporting requirement
to perform through a layoutreturn (e.g. flexfiles layout stats or error
information).

Fixes: 6d597e175012 ("pnfs: only tear down lsegs that precede seqid in LAYOUTRETURN args")
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22 10:57:21 +02:00
Filipe Manana
cc904e81a1 btrfs: fix race when picking most recent mod log operation for an old root
[ Upstream commit f9690f426b2134cc3e74bfc5d9dfd6a4b2ca5281 ]

Commit dbcc7d57bffc0c ("btrfs: fix race when cloning extent buffer during
rewind of an old root"), fixed a race when we need to rewind the extent
buffer of an old root. It was caused by picking a new mod log operation
for the extent buffer while getting a cloned extent buffer with an outdated
number of items (off by -1), because we cloned the extent buffer without
locking it first.

However there is still another similar race, but in the opposite direction.
The cloned extent buffer has a number of items that does not match the
number of tree mod log operations that are going to be replayed. This is
because right after we got the last (most recent) tree mod log operation to
replay and before locking and cloning the extent buffer, another task adds
a new pointer to the extent buffer, which results in adding a new tree mod
log operation and incrementing the number of items in the extent buffer.
So after cloning we have mismatch between the number of items in the extent
buffer and the number of mod log operations we are going to apply to it.
This results in hitting a BUG_ON() that produces the following stack trace:

   ------------[ cut here ]------------
   kernel BUG at fs/btrfs/tree-mod-log.c:675!
   invalid opcode: 0000 [#1] SMP KASAN PTI
   CPU: 3 PID: 4811 Comm: crawl_1215 Tainted: G        W         5.12.0-7d1efdf501f8-misc-next+ #99
   Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
   RIP: 0010:tree_mod_log_rewind+0x3b1/0x3c0
   Code: 05 48 8d 74 10 (...)
   RSP: 0018:ffffc90001027090 EFLAGS: 00010293
   RAX: 0000000000000000 RBX: ffff8880a8514600 RCX: ffffffffaa9e59b6
   RDX: 0000000000000007 RSI: dffffc0000000000 RDI: ffff8880a851462c
   RBP: ffffc900010270e0 R08: 00000000000000c0 R09: ffffed1004333417
   R10: ffff88802199a0b7 R11: ffffed1004333416 R12: 000000000000000e
   R13: ffff888135af8748 R14: ffff88818766ff00 R15: ffff8880a851462c
   FS:  00007f29acf62700(0000) GS:ffff8881f2200000(0000) knlGS:0000000000000000
   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
   CR2: 00007f0e6013f718 CR3: 000000010d42e003 CR4: 0000000000170ee0
   Call Trace:
    btrfs_get_old_root+0x16a/0x5c0
    ? lock_downgrade+0x400/0x400
    btrfs_search_old_slot+0x192/0x520
    ? btrfs_search_slot+0x1090/0x1090
    ? free_extent_buffer.part.61+0xd7/0x140
    ? free_extent_buffer+0x13/0x20
    resolve_indirect_refs+0x3e9/0xfc0
    ? lock_downgrade+0x400/0x400
    ? __kasan_check_read+0x11/0x20
    ? add_prelim_ref.part.11+0x150/0x150
    ? lock_downgrade+0x400/0x400
    ? __kasan_check_read+0x11/0x20
    ? lock_acquired+0xbb/0x620
    ? __kasan_check_write+0x14/0x20
    ? do_raw_spin_unlock+0xa8/0x140
    ? rb_insert_color+0x340/0x360
    ? prelim_ref_insert+0x12d/0x430
    find_parent_nodes+0x5c3/0x1830
    ? stack_trace_save+0x87/0xb0
    ? resolve_indirect_refs+0xfc0/0xfc0
    ? fs_reclaim_acquire+0x67/0xf0
    ? __kasan_check_read+0x11/0x20
    ? lockdep_hardirqs_on_prepare+0x210/0x210
    ? fs_reclaim_acquire+0x67/0xf0
    ? __kasan_check_read+0x11/0x20
    ? ___might_sleep+0x10f/0x1e0
    ? __kasan_kmalloc+0x9d/0xd0
    ? trace_hardirqs_on+0x55/0x120
    btrfs_find_all_roots_safe+0x142/0x1e0
    ? find_parent_nodes+0x1830/0x1830
    ? trace_hardirqs_on+0x55/0x120
    ? ulist_free+0x1f/0x30
    ? btrfs_inode_flags_to_xflags+0x50/0x50
    iterate_extent_inodes+0x20e/0x580
    ? tree_backref_for_extent+0x230/0x230
    ? release_extent_buffer+0x225/0x280
    ? read_extent_buffer+0xdd/0x110
    ? lock_downgrade+0x400/0x400
    ? __kasan_check_read+0x11/0x20
    ? lock_acquired+0xbb/0x620
    ? __kasan_check_write+0x14/0x20
    ? do_raw_spin_unlock+0xa8/0x140
    ? _raw_spin_unlock+0x22/0x30
    ? release_extent_buffer+0x225/0x280
    iterate_inodes_from_logical+0x129/0x170
    ? iterate_inodes_from_logical+0x129/0x170
    ? btrfs_inode_flags_to_xflags+0x50/0x50
    ? iterate_extent_inodes+0x580/0x580
    ? __vmalloc_node+0x92/0xb0
    ? init_data_container+0x34/0xb0
    ? init_data_container+0x34/0xb0
    ? kvmalloc_node+0x60/0x80
    btrfs_ioctl_logical_to_ino+0x158/0x230
    btrfs_ioctl+0x2038/0x4360
    ? __kasan_check_write+0x14/0x20
    ? mmput+0x3b/0x220
    ? btrfs_ioctl_get_supported_features+0x30/0x30
    ? __kasan_check_read+0x11/0x20
    ? __kasan_check_read+0x11/0x20
    ? lock_release+0xc8/0x650
    ? __might_fault+0x64/0xd0
    ? __kasan_check_read+0x11/0x20
    ? lock_downgrade+0x400/0x400
    ? lockdep_hardirqs_on_prepare+0x210/0x210
    ? lockdep_hardirqs_on_prepare+0x13/0x210
    ? _raw_spin_unlock_irqrestore+0x51/0x63
    ? __kasan_check_read+0x11/0x20
    ? do_vfs_ioctl+0xfc/0x9d0
    ? ioctl_file_clone+0xe0/0xe0
    ? lock_downgrade+0x400/0x400
    ? lockdep_hardirqs_on_prepare+0x210/0x210
    ? __kasan_check_read+0x11/0x20
    ? lock_release+0xc8/0x650
    ? __task_pid_nr_ns+0xd3/0x250
    ? __kasan_check_read+0x11/0x20
    ? __fget_files+0x160/0x230
    ? __fget_light+0xf2/0x110
    __x64_sys_ioctl+0xc3/0x100
    do_syscall_64+0x37/0x80
    entry_SYSCALL_64_after_hwframe+0x44/0xae
   RIP: 0033:0x7f29ae85b427
   Code: 00 00 90 48 8b (...)
   RSP: 002b:00007f29acf5fcf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
   RAX: ffffffffffffffda RBX: 00007f29acf5ff40 RCX: 00007f29ae85b427
   RDX: 00007f29acf5ff48 RSI: 00000000c038943b RDI: 0000000000000003
   RBP: 0000000001000000 R08: 0000000000000000 R09: 00007f29acf60120
   R10: 00005640d5fc7b00 R11: 0000000000000246 R12: 0000000000000003
   R13: 00007f29acf5ff48 R14: 00007f29acf5ff40 R15: 00007f29acf5fef8
   Modules linked in:
   ---[ end trace 85e5fce078dfbe04 ]---

  (gdb) l *(tree_mod_log_rewind+0x3b1)
  0xffffffff819e5b21 is in tree_mod_log_rewind (fs/btrfs/tree-mod-log.c:675).
  670                      * the modification. As we're going backwards, we do the
  671                      * opposite of each operation here.
  672                      */
  673                     switch (tm->op) {
  674                     case BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING:
  675                             BUG_ON(tm->slot < n);
  676                             fallthrough;
  677                     case BTRFS_MOD_LOG_KEY_REMOVE_WHILE_MOVING:
  678                     case BTRFS_MOD_LOG_KEY_REMOVE:
  679                             btrfs_set_node_key(eb, &tm->key, tm->slot);
  (gdb) quit

The following steps explain in more detail how it happens:

1) We have one tree mod log user (through fiemap or the logical ino ioctl),
   with a sequence number of 1, so we have fs_info->tree_mod_seq == 1.
   This is task A;

2) Another task is at ctree.c:balance_level() and we have eb X currently as
   the root of the tree, and we promote its single child, eb Y, as the new
   root.

   Then, at ctree.c:balance_level(), we call:

      ret = btrfs_tree_mod_log_insert_root(root->node, child, true);

3) At btrfs_tree_mod_log_insert_root() we create a tree mod log operation
   of type BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING, with a ->logical field
   pointing to ebX->start. We only have one item in eb X, so we create
   only one tree mod log operation, and store in the "tm_list" array;

4) Then, still at btrfs_tree_mod_log_insert_root(), we create a tree mod
   log element of operation type BTRFS_MOD_LOG_ROOT_REPLACE, ->logical set
   to ebY->start, ->old_root.logical set to ebX->start, ->old_root.level
   set to the level of eb X and ->generation set to the generation of eb X;

5) Then btrfs_tree_mod_log_insert_root() calls tree_mod_log_free_eb() with
   "tm_list" as argument. After that, tree_mod_log_free_eb() calls
   tree_mod_log_insert(). This inserts the mod log operation of type
   BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING from step 3 into the rbtree
   with a sequence number of 2 (and fs_info->tree_mod_seq set to 2);

6) Then, after inserting the "tm_list" single element into the tree mod
   log rbtree, the BTRFS_MOD_LOG_ROOT_REPLACE element is inserted, which
   gets the sequence number 3 (and fs_info->tree_mod_seq set to 3);

7) Back to ctree.c:balance_level(), we free eb X by calling
   btrfs_free_tree_block() on it. Because eb X was created in the current
   transaction, has no other references and writeback did not happen for
   it, we add it back to the free space cache/tree;

8) Later some other task B allocates the metadata extent from eb X, since
   it is marked as free space in the space cache/tree, and uses it as a
   node for some other btree;

9) The tree mod log user task calls btrfs_search_old_slot(), which calls
   btrfs_get_old_root(), and finally that calls tree_mod_log_oldest_root()
   with time_seq == 1 and eb_root == eb Y;

10) The first iteration of the while loop finds the tree mod log element
    with sequence number 3, for the logical address of eb Y and of type
    BTRFS_MOD_LOG_ROOT_REPLACE;

11) Because the operation type is BTRFS_MOD_LOG_ROOT_REPLACE, we don't
    break out of the loop, and set root_logical to point to
    tm->old_root.logical, which corresponds to the logical address of
    eb X;

12) On the next iteration of the while loop, the call to
    tree_mod_log_search_oldest() returns the smallest tree mod log element
    for the logical address of eb X, which has a sequence number of 2, an
    operation type of BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING and
    corresponds to the old slot 0 of eb X (eb X had only 1 item in it
    before being freed at step 7);

13) We then break out of the while loop and return the tree mod log
    operation of type BTRFS_MOD_LOG_ROOT_REPLACE (eb Y), and not the one
    for slot 0 of eb X, to btrfs_get_old_root();

14) At btrfs_get_old_root(), we process the BTRFS_MOD_LOG_ROOT_REPLACE
    operation and set "logical" to the logical address of eb X, which was
    the old root. We then call tree_mod_log_search() passing it the logical
    address of eb X and time_seq == 1;

15) But before calling tree_mod_log_search(), task B locks eb X, adds a
    key to eb X, which results in adding a tree mod log operation of type
    BTRFS_MOD_LOG_KEY_ADD, with a sequence number of 4, to the tree mod
    log, and increments the number of items in eb X from 0 to 1.
    Now fs_info->tree_mod_seq has a value of 4;

16) Task A then calls tree_mod_log_search(), which returns the most recent
    tree mod log operation for eb X, which is the one just added by task B
    at the previous step, with a sequence number of 4, a type of
    BTRFS_MOD_LOG_KEY_ADD and for slot 0;

17) Before task A locks and clones eb X, task A adds another key to eb X,
    which results in adding a new BTRFS_MOD_LOG_KEY_ADD mod log operation,
    with a sequence number of 5, for slot 1 of eb X, increments the
    number of items in eb X from 1 to 2, and unlocks eb X.
    Now fs_info->tree_mod_seq has a value of 5;

18) Task A then locks eb X and clones it. The clone has a value of 2 for
    the number of items and the pointer "tm" points to the tree mod log
    operation with sequence number 4, not the most recent one with a
    sequence number of 5, so there is mismatch between the number of
    mod log operations that are going to be applied to the cloned version
    of eb X and the number of items in the clone;

19) Task A then calls tree_mod_log_rewind() with the clone of eb X, the
    tree mod log operation with sequence number 4 and a type of
    BTRFS_MOD_LOG_KEY_ADD, and time_seq == 1;

20) At tree_mod_log_rewind(), we set the local variable "n" with a value
    of 2, which is the number of items in the clone of eb X.

    Then in the first iteration of the while loop, we process the mod log
    operation with sequence number 4, which is targeted at slot 0 and has
    a type of BTRFS_MOD_LOG_KEY_ADD. This results in decrementing "n" from
    2 to 1.

    Then we pick the next tree mod log operation for eb X, which is the
    tree mod log operation with a sequence number of 2, a type of
    BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING and for slot 0, it is the one
    added in step 5 to the tree mod log tree.

    We go back to the top of the loop to process this mod log operation,
    and because its slot is 0 and "n" has a value of 1, we hit the BUG_ON:

        (...)
        switch (tm->op) {
        case BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING:
                BUG_ON(tm->slot < n);
                fallthrough;
	(...)

Fix this by checking for a more recent tree mod log operation after locking
and cloning the extent buffer of the old root node, and use it as the first
operation to apply to the cloned extent buffer when rewinding it.

Stable backport notes: due to moved code and renames, in =< 5.11 the
change should be applied to ctree.c:get_old_root.

Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Link: https://lore.kernel.org/linux-btrfs/20210404040732.GZ32440@hungrycats.org/
Fixes: 834328a8493079 ("Btrfs: tree mod log's old roots could still be part of the tree")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-22 10:57:20 +02:00
Josef Bacik
2938b650de btrfs: convert logic BUG_ON()'s in replace_path to ASSERT()'s
[ Upstream commit 7a9213a93546e7eaef90e6e153af6b8fc7553f10 ]

A few BUG_ON()'s in replace_path are purely to keep us from making
logical mistakes, so replace them with ASSERT()'s.

Reviewed-by: Qu Wenruo <wqu@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>
2021-05-22 10:57:17 +02:00
Filipe Manana
f78801b4e3 btrfs: fix metadata extent leak after failure to create subvolume
commit 67addf29004c5be9fa0383c82a364bb59afc7f84 upstream.

When creating a subvolume we allocate an extent buffer for its root node
after starting a transaction. We setup a root item for the subvolume that
points to that extent buffer and then attempt to insert the root item into
the root tree - however if that fails, due to ENOMEM for example, we do
not free the extent buffer previously allocated and we do not abort the
transaction (as at that point we did nothing that can not be undone).

This means that we effectively do not return the metadata extent back to
the free space cache/tree and we leave a delayed reference for it which
causes a metadata extent item to be added to the extent tree, in the next
transaction commit, without having backreferences. When this happens
'btrfs check' reports the following:

  $ btrfs check /dev/sdi
  Opening filesystem to check...
  Checking filesystem on /dev/sdi
  UUID: dce2cb9d-025f-4b05-a4bf-cee0ad3785eb
  [1/7] checking root items
  [2/7] checking extents
  ref mismatch on [30425088 16384] extent item 1, found 0
  backref 30425088 root 256 not referenced back 0x564a91c23d70
  incorrect global backref count on 30425088 found 1 wanted 0
  backpointer mismatch on [30425088 16384]
  owner ref check failed [30425088 16384]
  ERROR: errors found in extent allocation tree or chunk allocation
  [3/7] checking free space cache
  [4/7] checking fs roots
  [5/7] checking only csums items (without verifying data)
  [6/7] checking root refs
  [7/7] checking quota groups skipped (not enabled on this FS)
  found 212992 bytes used, error(s) found
  total csum bytes: 0
  total tree bytes: 131072
  total fs tree bytes: 32768
  total extent tree bytes: 16384
  btree space waste bytes: 124669
  file data blocks allocated: 65536
   referenced 65536

So fix this by freeing the metadata extent if btrfs_insert_root() returns
an error.

CC: stable@vger.kernel.org # 4.4+
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>
2021-05-22 10:57:15 +02:00
Paul Aurich
e94851629c cifs: Return correct error code from smb2_get_enc_key
commit 83728cbf366e334301091d5b808add468ab46b27 upstream.

Avoid a warning if the error percolates back up:

[440700.376476] CIFS VFS: \\otters.example.com crypt_message: Could not get encryption key
[440700.386947] ------------[ cut here ]------------
[440700.386948] err = 1
[440700.386977] WARNING: CPU: 11 PID: 2733 at /build/linux-hwe-5.4-p6lk6L/linux-hwe-5.4-5.4.0/lib/errseq.c:74 errseq_set+0x5c/0x70
...
[440700.397304] CPU: 11 PID: 2733 Comm: tar Tainted: G           OE     5.4.0-70-generic #78~18.04.1-Ubuntu
...
[440700.397334] Call Trace:
[440700.397346]  __filemap_set_wb_err+0x1a/0x70
[440700.397419]  cifs_writepages+0x9c7/0xb30 [cifs]
[440700.397426]  do_writepages+0x4b/0xe0
[440700.397444]  __filemap_fdatawrite_range+0xcb/0x100
[440700.397455]  filemap_write_and_wait+0x42/0xa0
[440700.397486]  cifs_setattr+0x68b/0xf30 [cifs]
[440700.397493]  notify_change+0x358/0x4a0
[440700.397500]  utimes_common+0xe9/0x1c0
[440700.397510]  do_utimes+0xc5/0x150
[440700.397520]  __x64_sys_utimensat+0x88/0xd0

Fixes: 61cfac6f267d ("CIFS: Fix possible use after free in demultiplex thread")
Signed-off-by: Paul Aurich <paul@darkrain42.org>
CC: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22 10:57:15 +02:00
Jeffrey Mitchell
6b902a1e00 ecryptfs: fix kernel panic with null dev_name
commit 9046625511ad8dfbc8c6c2de16b3532c43d68d48 upstream.

When mounting eCryptfs, a null "dev_name" argument to ecryptfs_mount()
causes a kernel panic if the parsed options are valid. The easiest way to
reproduce this is to call mount() from userspace with an existing
eCryptfs mount's options and a "source" argument of 0.

Error out if "dev_name" is null in ecryptfs_mount()

Fixes: 237fead61998 ("[PATCH] ecryptfs: fs/Makefile and fs/Kconfig")
Cc: stable@vger.kernel.org
Signed-off-by: Jeffrey Mitchell <jeffrey.mitchell@starlab.io>
Signed-off-by: Tyler Hicks <code@tyhicks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22 10:57:15 +02:00
Zhang Yi
457ac0ff3e ext4: correct error label in ext4_rename()
The backport of upstream patch 5dccdc5a1916 ("ext4: do not iput inode
under running transaction in ext4_rename()") introduced a regression on
the stable kernels 4.14 and older. One of the end_rename error label was
forgetting to change to release_bh, which may trigger below bug.

 ------------[ cut here ]------------
 kernel BUG at /home/zhangyi/hulk-4.4/fs/ext4/ext4_jbd2.c:30!
 ...
 Call Trace:
  [<ffffffff8b4207b2>] ext4_rename+0x9e2/0x10c0
  [<ffffffff8b331324>] ? unlazy_walk+0x124/0x2a0
  [<ffffffff8b420eb5>] ext4_rename2+0x25/0x60
  [<ffffffff8b335104>] vfs_rename+0x3a4/0xed0
  [<ffffffff8b33a7ad>] SYSC_renameat2+0x57d/0x7f0
  [<ffffffff8b33c119>] SyS_renameat+0x19/0x30
  [<ffffffff8bc57bb8>] entry_SYSCALL_64_fastpath+0x18/0x78
 ...
 ---[ end trace 75346ce7c76b9f06 ]---

Fixes: d962f1b4ef54 ("ext4: do not iput inode under running transaction in ext4_rename()")
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-28 12:08:43 +02:00
Linus Torvalds
a0ea6bbfb9 readdir: make sure to verify directory entry for legacy interfaces too
commit 0c93ac69407d63a85be0129aa55ffaec27ffebd3 upstream.

This does the directory entry name verification for the legacy
"fillonedir" (and compat) interface that goes all the way back to the
dark ages before we had a proper dirent, and the readdir() system call
returned just a single entry at a time.

Nobody should use this interface unless you still have binaries from
1991, but let's do it right.

This came up during discussions about unsafe_copy_to_user() and proper
checking of all the inputs to it, as the networking layer is looking to
use it in a few new places.  So let's make sure the _old_ users do it
all right and proper, before we add new ones.

See also commit 8a23eb804ca4 ("Make filldir[64]() verify the directory
entry filename is valid") which did the proper modern interfaces that
people actually use. It had a note:

    Note that I didn't bother adding the checks to any legacy interfaces
    that nobody uses.

which this now corrects.  Note that we really don't care about POSIX and
the presense of '/' in a directory entry, but verify_dirent_name() also
ends up doing the proper name length verification which is what the
input checking discussion was about.

[ Another option would be to remove the support for this particular very
  old interface: any binaries that use it are likely a.out binaries, and
  they will no longer run anyway since we removed a.out binftm support
  in commit eac616557050 ("x86: Deprecate a.out support").

  But I'm not sure which came first: getdents() or ELF support, so let's
  pretend somebody might still have a working binary that uses the
  legacy readdir() case.. ]

Link: https://lore.kernel.org/lkml/CAHk-=wjbvzCAhAtvG0d81W5o0-KT5PPTHhfJ5ieDFq+bGtgOYg@mail.gmail.com/
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-28 12:08:41 +02:00
Bob Peterson
bbae0543ef gfs2: report "already frozen/thawed" errors
[ Upstream commit ff132c5f93c06bd4432bbab5c369e468653bdec4 ]

Before this patch, gfs2's freeze function failed to report an error
when the target file system was already frozen as it should (and as
generic vfs function freeze_super does. Similarly, gfs2's thaw function
failed to report an error when trying to thaw a file system that is not
frozen, as vfs function thaw_super does. The errors were checked, but
it always returned a 0 return code.

This patch adds the missing error return codes to gfs2 freeze and thaw.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-16 11:57:53 +02:00
Greg Kroah-Hartman
90bc77b708 Revert "cifs: Set CIFS_MOUNT_USE_PREFIX_PATH flag on setting cifs_sb->prepath."
This reverts commit ad48c641e7c344ae7aba243d3056a22eaba71bfd which is
commit a738c93fb1c17e386a09304b517b1c6b2a6a5a8b upstream.

It is reported to cause problems in older kernels, so revert it for now
until we can figure it out...

Reported-by: Salvatore Bonaccorso <carnil@debian.org>
Link: https://lore.kernel.org/r/YG7r0UaivWZL762N@eldamar.lan
Cc: Shyam Prasad N <sprasad@microsoft.com>
Cc: Aurelien Aptel <aaptel@suse.com>
Cc: Steve French <stfrench@microsoft.com>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-16 11:57:52 +02:00
Jack Qiu
badefcb13d fs: direct-io: fix missing sdio->boundary
commit df41872b68601059dd4a84858952dcae58acd331 upstream.

I encountered a hung task issue, but not a performance one.  I run DIO
on a device (need lba continuous, for example open channel ssd), maybe
hungtask in below case:

  DIO:						Checkpoint:
  get addr A(at boundary), merge into BIO,
  no submit because boundary missing
						flush dirty data(get addr A+1), wait IO(A+1)
						writeback timeout, because DIO(A) didn't submit
  get addr A+2 fail, because checkpoint is doing

dio_send_cur_page() may clear sdio->boundary, so prevent it from missing
a boundary.

Link: https://lkml.kernel.org/r/20210322042253.38312-1-jack.qiu@huawei.com
Fixes: b1058b981272 ("direct-io: submit bio after boundary buffer is added to it")
Signed-off-by: Jack Qiu <jack.qiu@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-16 11:57:48 +02:00
Wengang Wang
f77ee7a287 ocfs2: fix deadlock between setattr and dio_end_io_write
commit 90bd070aae6c4fb5d302f9c4b9c88be60c8197ec upstream.

The following deadlock is detected:

  truncate -> setattr path is waiting for pending direct IO to be done (inode->i_dio_count become zero) with inode->i_rwsem held (down_write).

  PID: 14827  TASK: ffff881686a9af80  CPU: 20  COMMAND: "ora_p005_hrltd9"
   #0  __schedule at ffffffff818667cc
   #1  schedule at ffffffff81866de6
   #2  inode_dio_wait at ffffffff812a2d04
   #3  ocfs2_setattr at ffffffffc05f322e [ocfs2]
   #4  notify_change at ffffffff812a5a09
   #5  do_truncate at ffffffff812808f5
   #6  do_sys_ftruncate.constprop.18 at ffffffff81280cf2
   #7  sys_ftruncate at ffffffff81280d8e
   #8  do_syscall_64 at ffffffff81003949
   #9  entry_SYSCALL_64_after_hwframe at ffffffff81a001ad

dio completion path is going to complete one direct IO (decrement
inode->i_dio_count), but before that it hung at locking inode->i_rwsem:

   #0  __schedule+700 at ffffffff818667cc
   #1  schedule+54 at ffffffff81866de6
   #2  rwsem_down_write_failed+536 at ffffffff8186aa28
   #3  call_rwsem_down_write_failed+23 at ffffffff8185a1b7
   #4  down_write+45 at ffffffff81869c9d
   #5  ocfs2_dio_end_io_write+180 at ffffffffc05d5444 [ocfs2]
   #6  ocfs2_dio_end_io+85 at ffffffffc05d5a85 [ocfs2]
   #7  dio_complete+140 at ffffffff812c873c
   #8  dio_aio_complete_work+25 at ffffffff812c89f9
   #9  process_one_work+361 at ffffffff810b1889
  #10  worker_thread+77 at ffffffff810b233d
  #11  kthread+261 at ffffffff810b7fd5
  #12  ret_from_fork+62 at ffffffff81a0035e

Thus above forms ABBA deadlock.  The same deadlock was mentioned in
upstream commit 28f5a8a7c033 ("ocfs2: should wait dio before inode lock
in ocfs2_setattr()").  It seems that that commit only removed the
cluster lock (the victim of above dead lock) from the ABBA deadlock
party.

End-user visible effects: Process hang in truncate -> ocfs2_setattr path
and other processes hang at ocfs2_dio_end_io_write path.

This is to fix the deadlock itself.  It removes inode_lock() call from
dio completion path to remove the deadlock and add ip_alloc_sem lock in
setattr path to synchronize the inode modifications.

[wen.gang.wang@oracle.com: remove the "had_alloc_lock" as suggested]
  Link: https://lkml.kernel.org/r/20210402171344.1605-1-wen.gang.wang@oracle.com

Link: https://lkml.kernel.org/r/20210331203654.3911-1-wen.gang.wang@oracle.com
Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.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: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-16 11:57:48 +02:00
Vincent Whitchurch
fee67e937a cifs: Silently ignore unknown oplock break handle
[ Upstream commit 219481a8f90ec3a5eed9638fb35609e4b1aeece7 ]

Make SMB2 not print out an error when an oplock break is received for an
unknown handle, similar to SMB1.  The debug message which is printed for
these unknown handles may also be misleading, so fix that too.

The SMB2 lease break path is not affected by this patch.

Without this, a program which writes to a file from one thread, and
opens, reads, and writes the same file from another thread triggers the
below errors several times a minute when run against a Samba server
configured with "smb2 leases = no".

 CIFS: VFS: \\192.168.0.1 No task to wake, unknown frame received! NumMids 2
 00000000: 424d53fe 00000040 00000000 00000012  .SMB@...........
 00000010: 00000001 00000000 ffffffff ffffffff  ................
 00000020: 00000000 00000000 00000000 00000000  ................
 00000030: 00000000 00000000 00000000 00000000  ................

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Reviewed-by: Tom Talpey <tom@talpey.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-10 13:20:11 +02:00
Ronnie Sahlberg
9e62e36658 cifs: revalidate mapping when we open files for SMB1 POSIX
[ Upstream commit cee8f4f6fcabfdf229542926128e9874d19016d5 ]

RHBZ: 1933527

Under SMB1 + POSIX, if an inode is reused on a server after we have read and
cached a part of a file, when we then open the new file with the
re-cycled inode there is a chance that we may serve the old data out of cache
to the application.
This only happens for SMB1 (deprecated) and when posix are used.
The simplest solution to avoid this race is to force a revalidate
on smb1-posix open.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-10 13:20:11 +02:00
Tetsuo Handa
323900f695 reiserfs: update reiserfs_xattrs_initialized() condition
commit 5e46d1b78a03d52306f21f77a4e4a144b6d31486 upstream.

syzbot is reporting NULL pointer dereference at reiserfs_security_init()
[1], for commit ab17c4f02156c4f7 ("reiserfs: fixup xattr_root caching")
is assuming that REISERFS_SB(s)->xattr_root != NULL in
reiserfs_xattr_jcreate_nblocks() despite that commit made
REISERFS_SB(sb)->priv_root != NULL && REISERFS_SB(s)->xattr_root == NULL
case possible.

I guess that commit 6cb4aff0a77cc0e6 ("reiserfs: fix oops while creating
privroot with selinux enabled") wanted to check xattr_root != NULL
before reiserfs_xattr_jcreate_nblocks(), for the changelog is talking
about the xattr root.

  The issue is that while creating the privroot during mount
  reiserfs_security_init calls reiserfs_xattr_jcreate_nblocks which
  dereferences the xattr root. The xattr root doesn't exist, so we get
  an oops.

Therefore, update reiserfs_xattrs_initialized() to check both the
privroot and the xattr root.

Link: https://syzkaller.appspot.com/bug?id=8abaedbdeb32c861dc5340544284167dd0e46cde # [1]
Reported-and-tested-by: syzbot <syzbot+690cb1e51970435f9775@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: 6cb4aff0a77c ("reiserfs: fix oops while creating privroot with selinux enabled")
Acked-by: Jeff Mahoney <jeffm@suse.com>
Acked-by: Jan Kara <jack@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-07 12:47:02 +02:00
zhangyi (F)
d962f1b4ef ext4: do not iput inode under running transaction in ext4_rename()
[ Upstream commit 5dccdc5a1916d4266edd251f20bbbb113a5c495f ]

In ext4_rename(), when RENAME_WHITEOUT failed to add new entry into
directory, it ends up dropping new created whiteout inode under the
running transaction. After commit <9b88f9fb0d2> ("ext4: Do not iput inode
under running transaction"), we follow the assumptions that evict() does
not get called from a transaction context but in ext4_rename() it breaks
this suggestion. Although it's not a real problem, better to obey it, so
this patch add inode to orphan list and stop transaction before final
iput().

Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20210303131703.330415-2-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-07 12:47:01 +02:00
Zhaolong Zhang
b3234384a2 ext4: fix bh ref count on error paths
[ Upstream commit c915fb80eaa6194fa9bd0a4487705cd5b0dda2f1 ]

__ext4_journalled_writepage should drop bhs' ref count on error paths

Signed-off-by: Zhaolong Zhang <zhangzl2013@126.com>
Link: https://lore.kernel.org/r/1614678151-70481-1-git-send-email-zhangzl2013@126.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-07 12:47:00 +02:00
Jan Kara
e436212b3f ext4: add reclaim checks to xattr code
commit 163f0ec1df33cf468509ff38cbcbb5eb0d7fac60 upstream.

Syzbot is reporting that ext4 can enter fs reclaim from kvmalloc() while
the transaction is started like:

  fs_reclaim_acquire+0x117/0x150 mm/page_alloc.c:4340
  might_alloc include/linux/sched/mm.h:193 [inline]
  slab_pre_alloc_hook mm/slab.h:493 [inline]
  slab_alloc_node mm/slub.c:2817 [inline]
  __kmalloc_node+0x5f/0x430 mm/slub.c:4015
  kmalloc_node include/linux/slab.h:575 [inline]
  kvmalloc_node+0x61/0xf0 mm/util.c:587
  kvmalloc include/linux/mm.h:781 [inline]
  ext4_xattr_inode_cache_find fs/ext4/xattr.c:1465 [inline]
  ext4_xattr_inode_lookup_create fs/ext4/xattr.c:1508 [inline]
  ext4_xattr_set_entry+0x1ce6/0x3780 fs/ext4/xattr.c:1649
  ext4_xattr_ibody_set+0x78/0x2b0 fs/ext4/xattr.c:2224
  ext4_xattr_set_handle+0x8f4/0x13e0 fs/ext4/xattr.c:2380
  ext4_xattr_set+0x13a/0x340 fs/ext4/xattr.c:2493

This should be impossible since transaction start sets PF_MEMALLOC_NOFS.
Add some assertions to the code to catch if something isn't working as
expected early.

Link: https://lore.kernel.org/linux-ext4/000000000000563a0205bafb7970@google.com/
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210222171626.21884-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-30 14:40:12 +02:00
Phillip Lougher
7f39bb5c47 squashfs: fix xattr id and id lookup sanity checks
commit 8b44ca2b634527151af07447a8090a5f3a043321 upstream.

The checks for maximum metadata block size is missing
SQUASHFS_BLOCK_OFFSET (the two byte length count).

Link: https://lkml.kernel.org/r/2069685113.2081245.1614583677427@webmail.123-reg.co.uk
Fixes: f37aa4c7366e23f ("squashfs: add more sanity checks in id lookup")
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Cc: Sean Nyekjaer <sean@geanix.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-30 14:40:09 +02:00
Sean Nyekjaer
6960691067 squashfs: fix inode lookup sanity checks
commit c1b2028315c6b15e8d6725e0d5884b15887d3daa upstream.

When mouting a squashfs image created without inode compression it fails
with: "unable to read inode lookup table"

It turns out that the BLOCK_OFFSET is missing when checking the
SQUASHFS_METADATA_SIZE agaist the actual size.

Link: https://lkml.kernel.org/r/20210226092903.1473545-1-sean@geanix.com
Fixes: eabac19e40c0 ("squashfs: add more sanity checks in inode lookup")
Signed-off-by: Sean Nyekjaer <sean@geanix.com>
Acked-by: Phillip Lougher <phillip@squashfs.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-30 14:40:09 +02:00
J. Bruce Fields
5fbe977185 nfs: we don't support removing system.nfs4_acl
[ Upstream commit 4f8be1f53bf615102d103c0509ffa9596f65b718 ]

The NFSv4 protocol doesn't have any notion of reomoving an attribute, so
removexattr(path,"system.nfs4_acl") doesn't make sense.

There's no documented return value.  Arguably it could be EOPNOTSUPP but
I'm a little worried an application might take that to mean that we
don't support ACLs or xattrs.  How about EINVAL?

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30 14:40:09 +02:00
Frank Sorenson
af528432f1 NFS: Correct size calculation for create reply length
[ Upstream commit ad3dbe35c833c2d4d0bbf3f04c785d32f931e7c9 ]

CREATE requests return a post_op_fh3, rather than nfs_fh3. The
post_op_fh3 includes an extra word to indicate 'handle_follows'.

Without that additional word, create fails when full 64-byte
filehandles are in use.

Add NFS3_post_op_fh_sz, and correct the size calculation for
NFS3_createres_sz.

Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30 14:40:08 +02:00
Timo Rothenpieler
972cbf2ac2 nfs: fix PNFS_FLEXFILE_LAYOUT Kconfig default
[ Upstream commit a0590473c5e6c4ef17c3132ad08fbad170f72d55 ]

This follows what was done in 8c2fabc6542d9d0f8b16bd1045c2eda59bdcde13.
With the default being m, it's impossible to build the module into the
kernel.

Signed-off-by: Timo Rothenpieler <timo@rothenpieler.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30 14:40:08 +02:00
Shijie Luo
fe778c33aa ext4: fix potential error in ext4_do_update_inode
commit 7d8bd3c76da1d94b85e6c9b7007e20e980bfcfe6 upstream.

If set_large_file = 1 and errors occur in ext4_handle_dirty_metadata(),
the error code will be overridden, go to out_brelse to avoid this
situation.

Signed-off-by: Shijie Luo <luoshijie1@huawei.com>
Link: https://lore.kernel.org/r/20210312065051.36314-1-luoshijie1@huawei.com
Cc: stable@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-24 11:05:06 +01:00
zhangyi (F)
470f69cb37 ext4: do not try to set xattr into ea_inode if value is empty
commit 6b22489911b726eebbf169caee52fea52013fbdd upstream.

Syzbot report a warning that ext4 may create an empty ea_inode if set
an empty extent attribute to a file on the file system which is no free
blocks left.

  WARNING: CPU: 6 PID: 10667 at fs/ext4/xattr.c:1640 ext4_xattr_set_entry+0x10f8/0x1114 fs/ext4/xattr.c:1640
  ...
  Call trace:
   ext4_xattr_set_entry+0x10f8/0x1114 fs/ext4/xattr.c:1640
   ext4_xattr_block_set+0x1d0/0x1b1c fs/ext4/xattr.c:1942
   ext4_xattr_set_handle+0x8a0/0xf1c fs/ext4/xattr.c:2390
   ext4_xattr_set+0x120/0x1f0 fs/ext4/xattr.c:2491
   ext4_xattr_trusted_set+0x48/0x5c fs/ext4/xattr_trusted.c:37
   __vfs_setxattr+0x208/0x23c fs/xattr.c:177
  ...

Now, ext4 try to store extent attribute into an external inode if
ext4_xattr_block_set() return -ENOSPC, but for the case of store an
empty extent attribute, store the extent entry into the extent
attribute block is enough. A simple reproduce below.

  fallocate test.img -l 1M
  mkfs.ext4 -F -b 2048 -O ea_inode test.img
  mount test.img /mnt
  dd if=/dev/zero of=/mnt/foo bs=2048 count=500
  setfattr -n "user.test" /mnt/foo

Reported-by: syzbot+98b881fdd8ebf45ab4ae@syzkaller.appspotmail.com
Fixes: 9c6e7853c531 ("ext4: reserve space for xattr entries/names")
Cc: stable@kernel.org
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20210305120508.298465-1-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-24 11:05:06 +01:00
zhangyi (F)
1b46d1d9d0 ext4: find old entry again if failed to rename whiteout
commit b7ff91fd030dc9d72ed91b1aab36e445a003af4f upstream.

If we failed to add new entry on rename whiteout, we cannot reset the
old->de entry directly, because the old->de could have moved from under
us during make indexed dir. So find the old entry again before reset is
needed, otherwise it may corrupt the filesystem as below.

  /dev/sda: Entry '00000001' in ??? (12) has deleted/unused inode 15. CLEARED.
  /dev/sda: Unattached inode 75
  /dev/sda: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.

Fixes: 6b4b8e6b4ad ("ext4: fix bug for rename with RENAME_WHITEOUT")
Cc: stable@vger.kernel.org
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20210303131703.330415-1-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-24 11:05:05 +01:00
Oleg Nesterov
591d6c21e0 kernel, fs: Introduce and use set_restart_fn() and arch_set_restart_data()
commit 5abbe51a526253b9f003e9a0a195638dc882d660 upstream.

Preparation for fixing get_nr_restart_syscall() on X86 for COMPAT.

Add a new helper which sets restart_block->fn and calls a dummy
arch_set_restart_data() helper.

Fixes: 609c19a385c8 ("x86/ptrace: Stop setting TS_COMPAT in ptrace code")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210201174641.GA17871@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-24 11:05:05 +01:00
Filipe Manana
0fbf41006d btrfs: fix race when cloning extent buffer during rewind of an old root
commit dbcc7d57bffc0c8cac9dac11bec548597d59a6a5 upstream.

While resolving backreferences, as part of a logical ino ioctl call or
fiemap, we can end up hitting a BUG_ON() when replaying tree mod log
operations of a root, triggering a stack trace like the following:

  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/ctree.c:1210!
  invalid opcode: 0000 [#1] SMP KASAN PTI
  CPU: 1 PID: 19054 Comm: crawl_335 Tainted: G        W         5.11.0-2d11c0084b02-misc-next+ #89
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
  RIP: 0010:__tree_mod_log_rewind+0x3b1/0x3c0
  Code: 05 48 8d 74 10 (...)
  RSP: 0018:ffffc90001eb70b8 EFLAGS: 00010297
  RAX: 0000000000000000 RBX: ffff88812344e400 RCX: ffffffffb28933b6
  RDX: 0000000000000007 RSI: dffffc0000000000 RDI: ffff88812344e42c
  RBP: ffffc90001eb7108 R08: 1ffff11020b60a20 R09: ffffed1020b60a20
  R10: ffff888105b050f9 R11: ffffed1020b60a1f R12: 00000000000000ee
  R13: ffff8880195520c0 R14: ffff8881bc958500 R15: ffff88812344e42c
  FS:  00007fd1955e8700(0000) GS:ffff8881f5600000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007efdb7928718 CR3: 000000010103a006 CR4: 0000000000170ee0
  Call Trace:
   btrfs_search_old_slot+0x265/0x10d0
   ? lock_acquired+0xbb/0x600
   ? btrfs_search_slot+0x1090/0x1090
   ? free_extent_buffer.part.61+0xd7/0x140
   ? free_extent_buffer+0x13/0x20
   resolve_indirect_refs+0x3e9/0xfc0
   ? lock_downgrade+0x3d0/0x3d0
   ? __kasan_check_read+0x11/0x20
   ? add_prelim_ref.part.11+0x150/0x150
   ? lock_downgrade+0x3d0/0x3d0
   ? __kasan_check_read+0x11/0x20
   ? lock_acquired+0xbb/0x600
   ? __kasan_check_write+0x14/0x20
   ? do_raw_spin_unlock+0xa8/0x140
   ? rb_insert_color+0x30/0x360
   ? prelim_ref_insert+0x12d/0x430
   find_parent_nodes+0x5c3/0x1830
   ? resolve_indirect_refs+0xfc0/0xfc0
   ? lock_release+0xc8/0x620
   ? fs_reclaim_acquire+0x67/0xf0
   ? lock_acquire+0xc7/0x510
   ? lock_downgrade+0x3d0/0x3d0
   ? lockdep_hardirqs_on_prepare+0x160/0x210
   ? lock_release+0xc8/0x620
   ? fs_reclaim_acquire+0x67/0xf0
   ? lock_acquire+0xc7/0x510
   ? poison_range+0x38/0x40
   ? unpoison_range+0x14/0x40
   ? trace_hardirqs_on+0x55/0x120
   btrfs_find_all_roots_safe+0x142/0x1e0
   ? find_parent_nodes+0x1830/0x1830
   ? btrfs_inode_flags_to_xflags+0x50/0x50
   iterate_extent_inodes+0x20e/0x580
   ? tree_backref_for_extent+0x230/0x230
   ? lock_downgrade+0x3d0/0x3d0
   ? read_extent_buffer+0xdd/0x110
   ? lock_downgrade+0x3d0/0x3d0
   ? __kasan_check_read+0x11/0x20
   ? lock_acquired+0xbb/0x600
   ? __kasan_check_write+0x14/0x20
   ? _raw_spin_unlock+0x22/0x30
   ? __kasan_check_write+0x14/0x20
   iterate_inodes_from_logical+0x129/0x170
   ? iterate_inodes_from_logical+0x129/0x170
   ? btrfs_inode_flags_to_xflags+0x50/0x50
   ? iterate_extent_inodes+0x580/0x580
   ? __vmalloc_node+0x92/0xb0
   ? init_data_container+0x34/0xb0
   ? init_data_container+0x34/0xb0
   ? kvmalloc_node+0x60/0x80
   btrfs_ioctl_logical_to_ino+0x158/0x230
   btrfs_ioctl+0x205e/0x4040
   ? __might_sleep+0x71/0xe0
   ? btrfs_ioctl_get_supported_features+0x30/0x30
   ? getrusage+0x4b6/0x9c0
   ? __kasan_check_read+0x11/0x20
   ? lock_release+0xc8/0x620
   ? __might_fault+0x64/0xd0
   ? lock_acquire+0xc7/0x510
   ? lock_downgrade+0x3d0/0x3d0
   ? lockdep_hardirqs_on_prepare+0x210/0x210
   ? lockdep_hardirqs_on_prepare+0x210/0x210
   ? __kasan_check_read+0x11/0x20
   ? do_vfs_ioctl+0xfc/0x9d0
   ? ioctl_file_clone+0xe0/0xe0
   ? lock_downgrade+0x3d0/0x3d0
   ? lockdep_hardirqs_on_prepare+0x210/0x210
   ? __kasan_check_read+0x11/0x20
   ? lock_release+0xc8/0x620
   ? __task_pid_nr_ns+0xd3/0x250
   ? lock_acquire+0xc7/0x510
   ? __fget_files+0x160/0x230
   ? __fget_light+0xf2/0x110
   __x64_sys_ioctl+0xc3/0x100
   do_syscall_64+0x37/0x80
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  RIP: 0033:0x7fd1976e2427
  Code: 00 00 90 48 8b 05 (...)
  RSP: 002b:00007fd1955e5cf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  RAX: ffffffffffffffda RBX: 00007fd1955e5f40 RCX: 00007fd1976e2427
  RDX: 00007fd1955e5f48 RSI: 00000000c038943b RDI: 0000000000000004
  RBP: 0000000001000000 R08: 0000000000000000 R09: 00007fd1955e6120
  R10: 0000557835366b00 R11: 0000000000000246 R12: 0000000000000004
  R13: 00007fd1955e5f48 R14: 00007fd1955e5f40 R15: 00007fd1955e5ef8
  Modules linked in:
  ---[ end trace ec8931a1c36e57be ]---

  (gdb) l *(__tree_mod_log_rewind+0x3b1)
  0xffffffff81893521 is in __tree_mod_log_rewind (fs/btrfs/ctree.c:1210).
  1205                     * the modification. as we're going backwards, we do the
  1206                     * opposite of each operation here.
  1207                     */
  1208                    switch (tm->op) {
  1209                    case MOD_LOG_KEY_REMOVE_WHILE_FREEING:
  1210                            BUG_ON(tm->slot < n);
  1211                            fallthrough;
  1212                    case MOD_LOG_KEY_REMOVE_WHILE_MOVING:
  1213                    case MOD_LOG_KEY_REMOVE:
  1214                            btrfs_set_node_key(eb, &tm->key, tm->slot);

Here's what happens to hit that BUG_ON():

1) We have one tree mod log user (through fiemap or the logical ino ioctl),
   with a sequence number of 1, so we have fs_info->tree_mod_seq == 1;

2) Another task is at ctree.c:balance_level() and we have eb X currently as
   the root of the tree, and we promote its single child, eb Y, as the new
   root.

   Then, at ctree.c:balance_level(), we call:

      tree_mod_log_insert_root(eb X, eb Y, 1);

3) At tree_mod_log_insert_root() we create tree mod log elements for each
   slot of eb X, of operation type MOD_LOG_KEY_REMOVE_WHILE_FREEING each
   with a ->logical pointing to ebX->start. These are placed in an array
   named tm_list.
   Lets assume there are N elements (N pointers in eb X);

4) Then, still at tree_mod_log_insert_root(), we create a tree mod log
   element of operation type MOD_LOG_ROOT_REPLACE, ->logical set to
   ebY->start, ->old_root.logical set to ebX->start, ->old_root.level set
   to the level of eb X and ->generation set to the generation of eb X;

5) Then tree_mod_log_insert_root() calls tree_mod_log_free_eb() with
   tm_list as argument. After that, tree_mod_log_free_eb() calls
   __tree_mod_log_insert() for each member of tm_list in reverse order,
   from highest slot in eb X, slot N - 1, to slot 0 of eb X;

6) __tree_mod_log_insert() sets the sequence number of each given tree mod
   log operation - it increments fs_info->tree_mod_seq and sets
   fs_info->tree_mod_seq as the sequence number of the given tree mod log
   operation.

   This means that for the tm_list created at tree_mod_log_insert_root(),
   the element corresponding to slot 0 of eb X has the highest sequence
   number (1 + N), and the element corresponding to the last slot has the
   lowest sequence number (2);

7) Then, after inserting tm_list's elements into the tree mod log rbtree,
   the MOD_LOG_ROOT_REPLACE element is inserted, which gets the highest
   sequence number, which is N + 2;

8) Back to ctree.c:balance_level(), we free eb X by calling
   btrfs_free_tree_block() on it. Because eb X was created in the current
   transaction, has no other references and writeback did not happen for
   it, we add it back to the free space cache/tree;

9) Later some other task T allocates the metadata extent from eb X, since
   it is marked as free space in the space cache/tree, and uses it as a
   node for some other btree;

10) The tree mod log user task calls btrfs_search_old_slot(), which calls
    get_old_root(), and finally that calls __tree_mod_log_oldest_root()
    with time_seq == 1 and eb_root == eb Y;

11) First iteration of the while loop finds the tree mod log element with
    sequence number N + 2, for the logical address of eb Y and of type
    MOD_LOG_ROOT_REPLACE;

12) Because the operation type is MOD_LOG_ROOT_REPLACE, we don't break out
    of the loop, and set root_logical to point to tm->old_root.logical
    which corresponds to the logical address of eb X;

13) On the next iteration of the while loop, the call to
    tree_mod_log_search_oldest() returns the smallest tree mod log element
    for the logical address of eb X, which has a sequence number of 2, an
    operation type of MOD_LOG_KEY_REMOVE_WHILE_FREEING and corresponds to
    the old slot N - 1 of eb X (eb X had N items in it before being freed);

14) We then break out of the while loop and return the tree mod log operation
    of type MOD_LOG_ROOT_REPLACE (eb Y), and not the one for slot N - 1 of
    eb X, to get_old_root();

15) At get_old_root(), we process the MOD_LOG_ROOT_REPLACE operation
    and set "logical" to the logical address of eb X, which was the old
    root. We then call tree_mod_log_search() passing it the logical
    address of eb X and time_seq == 1;

16) Then before calling tree_mod_log_search(), task T adds a key to eb X,
    which results in adding a tree mod log operation of type
    MOD_LOG_KEY_ADD to the tree mod log - this is done at
    ctree.c:insert_ptr() - but after adding the tree mod log operation
    and before updating the number of items in eb X from 0 to 1...

17) The task at get_old_root() calls tree_mod_log_search() and gets the
    tree mod log operation of type MOD_LOG_KEY_ADD just added by task T.
    Then it enters the following if branch:

    if (old_root && tm && tm->op != MOD_LOG_KEY_REMOVE_WHILE_FREEING) {
       (...)
    } (...)

    Calls read_tree_block() for eb X, which gets a reference on eb X but
    does not lock it - task T has it locked.
    Then it clones eb X while it has nritems set to 0 in its header, before
    task T sets nritems to 1 in eb X's header. From hereupon we use the
    clone of eb X which no other task has access to;

18) Then we call __tree_mod_log_rewind(), passing it the MOD_LOG_KEY_ADD
    mod log operation we just got from tree_mod_log_search() in the
    previous step and the cloned version of eb X;

19) At __tree_mod_log_rewind(), we set the local variable "n" to the number
    of items set in eb X's clone, which is 0. Then we enter the while loop,
    and in its first iteration we process the MOD_LOG_KEY_ADD operation,
    which just decrements "n" from 0 to (u32)-1, since "n" is declared with
    a type of u32. At the end of this iteration we call rb_next() to find the
    next tree mod log operation for eb X, that gives us the mod log operation
    of type MOD_LOG_KEY_REMOVE_WHILE_FREEING, for slot 0, with a sequence
    number of N + 1 (steps 3 to 6);

20) Then we go back to the top of the while loop and trigger the following
    BUG_ON():

        (...)
        switch (tm->op) {
        case MOD_LOG_KEY_REMOVE_WHILE_FREEING:
                 BUG_ON(tm->slot < n);
                 fallthrough;
        (...)

    Because "n" has a value of (u32)-1 (4294967295) and tm->slot is 0.

Fix this by taking a read lock on the extent buffer before cloning it at
ctree.c:get_old_root(). This should be done regardless of the extent
buffer having been freed and reused, as a concurrent task might be
modifying it (while holding a write lock on it).

Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Link: https://lore.kernel.org/linux-btrfs/20210227155037.GN28049@hungrycats.org/
Fixes: 834328a8493079 ("Btrfs: tree mod log's old roots could still be part of the tree")
CC: stable@vger.kernel.org # 4.4+
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>
2021-03-24 11:05:00 +01:00