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BUG: KASAN: use-after-free in debugfs_remove+0x10d/0x130 /fs/debugfs/inode.c:705
Read of size 8 at addr ffff8880a6a194a0 by task kworker/0:1/12

CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.2.0+ #90
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events __blk_release_queue
Call Trace:
 __dump_stack /lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 /lib/dump_stack.c:113
 print_address_description.cold+0xd4/0x306 /mm/kasan/report.c:351
 __kasan_report.cold+0x1b/0x36 /mm/kasan/report.c:482
 kasan_report+0x12/0x17 /mm/kasan/common.c:612
 __asan_report_load8_noabort+0x14/0x20 /mm/kasan/generic_report.c:132
 debugfs_remove+0x10d/0x130 /fs/debugfs/inode.c:705
 blk_trace_free+0x38/0x140 /kernel/trace/blktrace.c:312
 blk_trace_cleanup /kernel/trace/blktrace.c:339 [inline]
 __blk_trace_remove+0x78/0xa0 /kernel/trace/blktrace.c:352
 blk_trace_shutdown+0x67/0x90 /kernel/trace/blktrace.c:747
 __blk_release_queue+0x1de/0x340 /block/blk-sysfs.c:902
 process_one_work+0x9af/0x1740 /kernel/workqueue.c:2269
 worker_thread+0x98/0xe40 /kernel/workqueue.c:2415
 kthread+0x361/0x430 /kernel/kthread.c:255
 ret_from_fork+0x24/0x30 /arch/x86/entry/entry_64.S:352

Allocated by task 8685:
 save_stack+0x23/0x90 /mm/kasan/common.c:69
 set_track /mm/kasan/common.c:77 [inline]
 __kasan_kmalloc /mm/kasan/common.c:487 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 /mm/kasan/common.c:460
 kasan_slab_alloc+0xf/0x20 /mm/kasan/common.c:495
 slab_post_alloc_hook /mm/slab.h:520 [inline]
 slab_alloc /mm/slab.c:3319 [inline]
 kmem_cache_alloc+0x121/0x710 /mm/slab.c:3483
 __d_alloc+0x2e/0x8c0 /fs/dcache.c:1622
 d_alloc+0x4d/0x280 /fs/dcache.c:1701
 d_alloc_parallel+0xf4/0x1c30 /fs/dcache.c:2453
 __lookup_slow+0x1ab/0x500 /fs/namei.c:1652
 lookup_one_len+0x16d/0x1a0 /fs/namei.c:2541
 start_creating+0xc5/0x1d0 /fs/debugfs/inode.c:312
 __debugfs_create_file+0x65/0x3c0 /fs/debugfs/inode.c:357
 debugfs_create_file+0x5a/0x70 /fs/debugfs/inode.c:413
 do_blk_trace_setup+0x361/0xb50 /kernel/trace/blktrace.c:524
 __blk_trace_setup+0xe3/0x190 /kernel/trace/blktrace.c:571
 blk_trace_ioctl+0x170/0x300 /kernel/trace/blktrace.c:710
 blkdev_ioctl+0x126/0x1c1a /block/ioctl.c:592
 block_ioctl+0xee/0x130 /fs/block_dev.c:1918
 vfs_ioctl /fs/ioctl.c:46 [inline]
 file_ioctl /fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0xdb6/0x13e0 /fs/ioctl.c:696
 ksys_ioctl+0xab/0xd0 /fs/ioctl.c:713
 __do_sys_ioctl /fs/ioctl.c:720 [inline]
 __se_sys_ioctl /fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 /fs/ioctl.c:718
 do_syscall_64+0xfd/0x6a0 /arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 0:
 save_stack+0x23/0x90 /mm/kasan/common.c:69
 set_track /mm/kasan/common.c:77 [inline]
 __kasan_slab_free+0x102/0x150 /mm/kasan/common.c:449
 kasan_slab_free+0xe/0x10 /mm/kasan/common.c:457
 __cache_free /mm/slab.c:3425 [inline]
 kmem_cache_free+0x86/0x320 /mm/slab.c:3693
 __d_free+0x20/0x30 /fs/dcache.c:271
 __rcu_reclaim /kernel/rcu/rcu.h:222 [inline]
 rcu_do_batch /kernel/rcu/tree.c:2114 [inline]
 rcu_core+0x67f/0x1580 /kernel/rcu/tree.c:2314
 rcu_core_si+0x9/0x10 /kernel/rcu/tree.c:2323
 __do_softirq+0x262/0x98c /kernel/softirq.c:292

The buggy address belongs to the object at ffff8880a6a19460
 which belongs to the cache dentry of size 288
The buggy address is located 64 bytes inside of
 288-byte region [ffff8880a6a19460, ffff8880a6a19580)
The buggy address belongs to the page:
page:ffffea00029a8640 refcount:1 mapcount:0 mapping:ffff88821bc46540 index:0x0
flags: 0x1fffc0000000200(slab)
raw: 01fffc0000000200 ffffea0002254608 ffffea00022534c8 ffff88821bc46540
raw: 0000000000000000 ffff8880a6a19040 000000010000000b 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a6a19380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880a6a19400: fb fb fb fb fc fc fc fc fc fc fc fc fb fb fb fb
>ffff8880a6a19480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff8880a6a19500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880a6a19580: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
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