KASAN: use-after-free Read in xfs_log_force_umount

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: a8ad60f2af58 Linux 4.14.305
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1544fee7480000
kernel config: https://syzkaller.appspot.com/x/.config?x=2f23dc9802022031
dashboard link: https://syzkaller.appspot.com/bug?extid=3d48c2932bfe773c7043
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c38348fd389d/disk-a8ad60f2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3a775d221689/vmlinux-a8ad60f2.xz
kernel image: https://storage.googleapis.com/syzbot-assets/32e71e04d2b4/bzImage-a8ad60f2.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3d48c2...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x2c57/0x3f20 kernel/locking/lockdep.c:3369
Read of size 8 at addr ffff88805db01c58 by task kworker/1:1H/2796

CPU: 1 PID: 2796 Comm: kworker/1:1H Not tainted 4.14.305-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
Workqueue: xfs-log/loop1 xfs_buf_ioend_work
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x1b2/0x281 lib/dump_stack.c:58
print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:251
kasan_report_error.cold+0x8a/0x191 mm/kasan/report.c:350
kasan_report mm/kasan/report.c:408 [inline]
__asan_report_load8_noabort+0x68/0x70 mm/kasan/report.c:429
__lock_acquire+0x2c57/0x3f20 kernel/locking/lockdep.c:3369
lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998
__raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:152
spin_lock include/linux/spinlock.h:317 [inline]
xfs_log_force_umount+0x24b/0x430 fs/xfs/xfs_log.c:4052
xfs_do_force_shutdown+0x78/0x200 fs/xfs/xfs_fsops.c:968
xlog_iodone+0x15b/0x1e0 fs/xfs/xfs_log.c:1244
xfs_buf_ioend+0x248/0x640 fs/xfs/xfs_buf.c:1191
process_one_work+0x793/0x14a0 kernel/workqueue.c:2117
worker_thread+0x5cc/0xff0 kernel/workqueue.c:2251
kthread+0x30d/0x420 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:406

Allocated by task 11039:
save_stack mm/kasan/kasan.c:447 [inline]
set_track mm/kasan/kasan.c:459 [inline]
kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551
__do_kmalloc mm/slab.c:3720 [inline]
__kmalloc+0x15a/0x400 mm/slab.c:3729
kmalloc include/linux/slab.h:493 [inline]
kmem_alloc+0x7f/0x180 fs/xfs/kmem.c:36
kmem_zalloc fs/xfs/kmem.h:85 [inline]
xlog_cil_init+0x1d/0x490 fs/xfs/xfs_log_cil.c:1172
xlog_alloc_log+0xe9d/0x1220 fs/xfs/xfs_log.c:1543
xfs_log_mount+0xbf/0x6b0 fs/xfs/xfs_log.c:625
xfs_mountfs+0xc5a/0x1f40 fs/xfs/xfs_mount.c:839
xfs_fs_fill_super+0xb7a/0x1380 fs/xfs/xfs_super.c:1688
mount_bdev+0x2b3/0x360 fs/super.c:1134
mount_fs+0x92/0x2a0 fs/super.c:1237
vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046
vfs_kern_mount fs/namespace.c:1036 [inline]
do_new_mount fs/namespace.c:2572 [inline]
do_mount+0xe65/0x2a30 fs/namespace.c:2905
SYSC_mount fs/namespace.c:3121 [inline]
SyS_mount+0xa8/0x120 fs/namespace.c:3098
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x5e/0xd3

Freed by task 7983:
save_stack mm/kasan/kasan.c:447 [inline]
set_track mm/kasan/kasan.c:459 [inline]
kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524
__cache_free mm/slab.c:3496 [inline]
kfree+0xc9/0x250 mm/slab.c:3815
kvfree+0x45/0x50 mm/util.c:451
xlog_dealloc_log+0x1e/0x480 fs/xfs/xfs_log.c:1974
xfs_unmountfs+0x1fe/0x5e0 fs/xfs/xfs_mount.c:1142
xfs_fs_put_super+0x62/0x130 fs/xfs/xfs_super.c:1742
generic_shutdown_super+0x144/0x370 fs/super.c:446
kill_block_super+0x95/0xe0 fs/super.c:1161
deactivate_locked_super+0x6c/0xd0 fs/super.c:319
deactivate_super+0x7f/0xa0 fs/super.c:350
cleanup_mnt+0x186/0x2c0 fs/namespace.c:1183
task_work_run+0x11f/0x190 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:191 [inline]
exit_to_usermode_loop+0x1ad/0x200 arch/x86/entry/common.c:164
prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297
entry_SYSCALL_64_after_hwframe+0x5e/0xd3

The buggy address belongs to the object at ffff88805db01b00
which belongs to the cache kmalloc-1024 of size 1024
The buggy address is located 344 bytes inside of
1024-byte region [ffff88805db01b00, ffff88805db01f00)
The buggy address belongs to the page:
page:ffffea000176c000 count:1 mapcount:0 mapping:ffff88805db00000 index:0x0 compound_mapcount: 0
flags: 0xfff00000008100(slab|head)
raw: 00fff00000008100 ffff88805db00000 0000000000000000 0000000100000007
raw: ffffea0002ae7420 ffffea000176dda0 ffff88813fe74ac0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff88805db01b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88805db01b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88805db01c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88805db01c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88805db01d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


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