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BUG: KASAN: use-after-free in __lock_acquire+0x40aa/0x55d0 kernel/locking/lockdep.c:4666
Read of size 8 at addr ffff88821af40818 by task io_wqe_worker-0/8399

CPU: 1 PID: 8399 Comm: io_wqe_worker-0 Not tainted 5.9.0-rc4-next-20200911-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x198/0x1fb lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 __lock_acquire+0x40aa/0x55d0 kernel/locking/lockdep.c:4666
 lock_acquire+0x1f2/0xaa0 kernel/locking/lockdep.c:5398
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
 _raw_spin_lock_irq+0x94/0xd0 kernel/locking/spinlock.c:167
 io_wqe_worker+0xdb0/0x10d0 fs/io-wq.c:589
 kthread+0x3af/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Allocated by task 8396:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461
 kmem_cache_alloc_node_trace+0x19f/0x560 mm/slab.c:3594
 kmalloc_node include/linux/slab.h:572 [inline]
 kzalloc_node include/linux/slab.h:677 [inline]
 io_wq_create+0x57b/0xa10 fs/io-wq.c:1064
 io_init_wq_offload fs/io_uring.c:7750 [inline]
 io_sq_offload_create fs/io_uring.c:7843 [inline]
 io_uring_create fs/io_uring.c:9035 [inline]
 io_uring_setup+0x243b/0x3060 fs/io_uring.c:9118
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 8334:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56
 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355
 __kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422
 __cache_free mm/slab.c:3418 [inline]
 kfree+0x10e/0x2a0 mm/slab.c:3756
 __io_wq_destroy fs/io-wq.c:1138 [inline]
 io_wq_destroy+0x2af/0x460 fs/io-wq.c:1146
 io_finish_async fs/io_uring.c:7154 [inline]
 io_ring_ctx_free fs/io_uring.c:8218 [inline]
 io_ring_exit_work+0x132/0x5f0 fs/io_uring.c:8301
 process_one_work+0x933/0x15a0 kernel/workqueue.c:2269
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
 kthread+0x3af/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

The buggy address belongs to the object at ffff88821af40800
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 24 bytes inside of
 1024-byte region [ffff88821af40800, ffff88821af40c00)
The buggy address belongs to the page:
page:00000000990a38ba refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x21af40
flags: 0x57ffe0000000200(slab)
raw: 057ffe0000000200 ffffea0008619e48 ffffea0008619588 ffff8880aa040700
raw: 0000000000000000 ffff88821af40000 0000000100000002 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88821af40700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88821af40780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88821af40800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88821af40880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88821af40900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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