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BUG: KASAN: use-after-free in debugfs_remove+0x4f/0xf0 fs/debugfs/inode.c:705
Read of size 8 at addr ffff88804023d600 by task kworker/0:5/10137

CPU: 0 PID: 10137 Comm: kworker/0:5 Not tainted 5.3.0+ #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:77 [inline]
 dump_stack+0x1d8/0x2f8 lib/dump_stack.c:113
 print_address_description+0x75/0x5c0 mm/kasan/report.c:374
 __kasan_report+0x14b/0x1c0 mm/kasan/report.c:506
 kasan_report+0x26/0x50 mm/kasan/common.c:634
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132
 debugfs_remove+0x4f/0xf0 fs/debugfs/inode.c:705
 blk_trace_free kernel/trace/blktrace.c:312 [inline]
 blk_trace_cleanup kernel/trace/blktrace.c:339 [inline]
 __blk_trace_remove+0xa5/0x180 kernel/trace/blktrace.c:352
 blk_trace_shutdown+0x20b/0x260 kernel/trace/blktrace.c:747
 __blk_release_queue+0x244/0x2e0 block/blk-sysfs.c:905
 process_one_work+0x7ef/0x10e0 kernel/workqueue.c:2269
 worker_thread+0xc01/0x1630 kernel/workqueue.c:2415
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Allocated by task 19788:
 save_stack mm/kasan/common.c:69 [inline]
 set_track mm/kasan/common.c:77 [inline]
 __kasan_kmalloc+0x11c/0x1b0 mm/kasan/common.c:510
 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:518
 slab_post_alloc_hook mm/slab.h:584 [inline]
 slab_alloc mm/slab.c:3319 [inline]
 kmem_cache_alloc+0x1f5/0x2e0 mm/slab.c:3483
 __d_alloc+0x2d/0x6e0 fs/dcache.c:1688
 d_alloc fs/dcache.c:1767 [inline]
 d_alloc_parallel+0x7f/0x1430 fs/dcache.c:2519
 __lookup_slow+0xa7/0x380 fs/namei.c:1646
 lookup_one_len+0x123/0x220 fs/namei.c:2533
 start_creating+0xd3/0x270 fs/debugfs/inode.c:312
 __debugfs_create_file+0x75/0x450 fs/debugfs/inode.c:357
 debugfs_create_file+0x4a/0x60 fs/debugfs/inode.c:413
 do_blk_trace_setup+0x439/0xaa0 kernel/trace/blktrace.c:524
 __blk_trace_setup kernel/trace/blktrace.c:571 [inline]
 blk_trace_ioctl+0x24c/0x7d0 kernel/trace/blktrace.c:710
 blkdev_ioctl+0x1363/0x2990 block/ioctl.c:592
 block_ioctl+0xbd/0x100 fs/block_dev.c:1954
 do_vfs_ioctl+0x744/0x1730 fs/ioctl.c:46
 ksys_ioctl fs/ioctl.c:713 [inline]
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0xe3/0x120 fs/ioctl.c:718
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 16:
 save_stack mm/kasan/common.c:69 [inline]
 set_track mm/kasan/common.c:77 [inline]
 kasan_set_free_info mm/kasan/common.c:332 [inline]
 __kasan_slab_free+0x12a/0x1e0 mm/kasan/common.c:471
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:480
 __cache_free mm/slab.c:3425 [inline]
 kmem_cache_free+0x81/0xf0 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:2157 [inline]
 rcu_core+0x843/0x1050 kernel/rcu/tree.c:2377
 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2386
 __do_softirq+0x333/0x7c4 arch/x86/include/asm/paravirt.h:766

The buggy address belongs to the object at ffff88804023d5c0
 which belongs to the cache dentry(17:syz0) of size 288
The buggy address is located 64 bytes inside of
 288-byte region [ffff88804023d5c0, ffff88804023d6e0)
The buggy address belongs to the page:
page:ffffea0001008f40 refcount:1 mapcount:0 mapping:ffff88809c1ff1c0 index:0xffff88804023d1a0
flags: 0x1fffc0000000200(slab)
raw: 01fffc0000000200 ffffea0001f96708 ffffea0001022b08 ffff88809c1ff1c0
raw: ffff88804023d1a0 ffff88804023d040 0000000100000008 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88804023d500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88804023d580: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
>ffff88804023d600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88804023d680: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff88804023d700: fc fc fc fc fb fb fb fb fb fb fb fb fb fb fb fb
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