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BUG: KASAN: use-after-free in debugfs_remove fs/debugfs/inode.c:662 [inline]
BUG: KASAN: use-after-free in debugfs_remove+0xef/0x110 fs/debugfs/inode.c:654
Read of size 8 at addr ffff88803f350a60 by task kworker/1:6/15114

CPU: 1 PID: 15114 Comm: kworker/1:6 Not tainted 4.14.174-syzkaller #0
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:17 [inline]
 dump_stack+0x13e/0x194 lib/dump_stack.c:58
 print_address_description.cold+0x7c/0x1e2 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0xa9/0x2ae mm/kasan/report.c:393
 debugfs_remove fs/debugfs/inode.c:662 [inline]
 debugfs_remove+0xef/0x110 fs/debugfs/inode.c:654
 blk_trace_free+0x31/0x130 kernel/trace/blktrace.c:324
 blk_trace_cleanup kernel/trace/blktrace.c:351 [inline]
 blk_trace_remove+0x52/0x80 kernel/trace/blktrace.c:364
 blk_trace_shutdown+0x48/0x60 kernel/trace/blktrace.c:728
 __blk_release_queue+0x227/0x4b0 block/blk-sysfs.c:830
 process_one_work+0x813/0x1540 kernel/workqueue.c:2116
 worker_thread+0x5d1/0x1070 kernel/workqueue.c:2250
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404

Allocated by task 10222:
 save_stack+0x32/0xa0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc mm/kasan/kasan.c:551 [inline]
 kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:529
 kmem_cache_alloc+0x127/0x770 mm/slab.c:3552
 __d_alloc+0x2a/0x9b0 fs/dcache.c:1623
 d_alloc+0x46/0x250 fs/dcache.c:1710
 __lookup_hash fs/namei.c:1571 [inline]
 __lookup_hash+0x51/0x180 fs/namei.c:1563
 lookup_one_len+0x27c/0x3a0 fs/namei.c:2539
 start_creating fs/debugfs/inode.c:314 [inline]
 start_creating+0xa1/0x1c0 fs/debugfs/inode.c:290
 __debugfs_create_file+0x4f/0x3c0 fs/debugfs/inode.c:353
 do_blk_trace_setup+0x319/0xad0 kernel/trace/blktrace.c:529
 blk_trace_setup+0xa3/0x120 kernel/trace/blktrace.c:579
 blk_trace_ioctl+0x13b/0x260 kernel/trace/blktrace.c:694
 blkdev_ioctl+0xe9/0x17d0 block/ioctl.c:580
 block_ioctl+0xd9/0x120 fs/block_dev.c:1881
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Freed by task 10203:
 save_stack+0x32/0xa0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x75/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kmem_cache_free+0x7c/0x2b0 mm/slab.c:3758
 __rcu_reclaim kernel/rcu/rcu.h:195 [inline]
 rcu_do_batch kernel/rcu/tree.c:2699 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2962 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2929 [inline]
 rcu_process_callbacks+0x792/0x1190 kernel/rcu/tree.c:2946
 __do_softirq+0x254/0x9bf kernel/softirq.c:288

The buggy address belongs to the object at ffff88803f350a20
 which belongs to the cache dentry of size 288
The buggy address is located 64 bytes inside of
 288-byte region [ffff88803f350a20, ffff88803f350b40)
The buggy address belongs to the page:
page:ffffea0000fcd400 count:1 mapcount:0 mapping:ffff88803f350080 index:0x0
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffff88803f350080 0000000000000000 000000010000000b
raw: ffffea0001f7a920 ffffea000245f3a0 ffff88821f8c1800 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88803f350900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88803f350980: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff88803f350a00: fc fc fc fc fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff88803f350a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88803f350b00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
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