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BUG: KASAN: use-after-free in __mutex_lock_common kernel/locking/mutex.c:938 [inline]
BUG: KASAN: use-after-free in __mutex_lock+0x102f/0x1110 kernel/locking/mutex.c:1103
Read of size 8 at addr ffff8880231413e0 by task syz-executor.4/12390

CPU: 1 PID: 12390 Comm: syz-executor.4 Not tainted 5.10.0-next-20201215-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:120
 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:230
 __kasan_report mm/kasan/report.c:396 [inline]
 kasan_report.cold+0x79/0xd5 mm/kasan/report.c:413
 __mutex_lock_common kernel/locking/mutex.c:938 [inline]
 __mutex_lock+0x102f/0x1110 kernel/locking/mutex.c:1103
 io_ring_ctx_wait_and_kill+0x21/0x450 fs/io_uring.c:8648
 io_uring_release+0x3e/0x50 fs/io_uring.c:8687
 __fput+0x283/0x920 fs/file_table.c:280
 task_work_run+0xdd/0x190 kernel/task_work.c:140
 exit_task_work include/linux/task_work.h:30 [inline]
 do_exit+0xb89/0x2a00 kernel/exit.c:823
 do_group_exit+0x125/0x310 kernel/exit.c:920
 get_signal+0x3e9/0x2160 kernel/signal.c:2770
 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x124/0x200 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45e159
Code: Unable to access opcode bytes at RIP 0x45e12f.
RSP: 002b:00007fbc4a6eebe8 EFLAGS: 00000206 ORIG_RAX: 00000000000001a9
RAX: fffffffffffffff4 RBX: 0000000020000140 RCX: 000000000045e159
RDX: 0000000020fff000 RSI: 0000000020000140 RDI: 00000000000076d1
RBP: 000000000119c080 R08: 0000000020000080 R09: 0000000020000080
R10: 0000000020000000 R11: 0000000000000206 R12: 0000000020fff000
R13: 0000000020ffd000 R14: 0000000020000080 R15: 0000000020000000

Allocated by task 12390:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:39
 kasan_set_track mm/kasan/common.c:47 [inline]
 set_alloc_info mm/kasan/common.c:405 [inline]
 ____kasan_kmalloc mm/kasan/common.c:436 [inline]
 ____kasan_kmalloc.constprop.0+0xa0/0xd0 mm/kasan/common.c:408
 kmalloc include/linux/slab.h:552 [inline]
 kzalloc include/linux/slab.h:682 [inline]
 io_ring_ctx_alloc fs/io_uring.c:1268 [inline]
 io_uring_create fs/io_uring.c:9480 [inline]
 io_uring_setup+0x51a/0x38b0 fs/io_uring.c:9613
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 11916:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:39
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:47
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:355
 ____kasan_slab_free.part.0+0xe1/0x110 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:188 [inline]
 slab_free_hook mm/slub.c:1548 [inline]
 slab_free_freelist_hook+0x82/0x1d0 mm/slub.c:1586
 slab_free mm/slub.c:3157 [inline]
 kfree+0xdb/0x3c0 mm/slub.c:4156
 process_one_work+0x98d/0x1630 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Last potentially related work creation:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:39
 kasan_record_aux_stack+0xdc/0x100 mm/kasan/generic.c:343
 insert_work+0x48/0x370 kernel/workqueue.c:1331
 __queue_work+0x5c1/0xfb0 kernel/workqueue.c:1497
 queue_work_on+0xc7/0xd0 kernel/workqueue.c:1524
 io_uring_create fs/io_uring.c:9586 [inline]
 io_uring_setup+0x1358/0x38b0 fs/io_uring.c:9613
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff888023141000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 992 bytes inside of
 2048-byte region [ffff888023141000, ffff888023141800)
The buggy address belongs to the page:
page:000000006673c311 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x23140
head:000000006673c311 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head)
raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888010842000
raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888023141280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888023141300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888023141380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff888023141400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888023141480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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