==================================================================
BUG: KASAN: use-after-free in debugfs_remove+0x1c1/0x210 fs/debugfs/inode.c:687
Read of size 8 at addr ffff8880417ef4e0 by task syz-executor.4/16259

CPU: 1 PID: 16259 Comm: syz-executor.4 Not tainted 4.19.136-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+0x1fc/0x2fe lib/dump_stack.c:118
 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
 kasan_report_error.cold+0x8a/0x1c7 mm/kasan/report.c:354
 kasan_report mm/kasan/report.c:412 [inline]
 __asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433
 debugfs_remove+0x1c1/0x210 fs/debugfs/inode.c:687
 blk_trace_free+0x31/0x130 kernel/trace/blktrace.c:315
 blk_trace_cleanup kernel/trace/blktrace.c:343 [inline]
 __blk_trace_remove+0x8b/0x100 kernel/trace/blktrace.c:356
 blk_trace_ioctl+0x23b/0x290 kernel/trace/blktrace.c:746
 blkdev_ioctl+0x112/0x1a7e block/ioctl.c:587
 block_ioctl+0xe9/0x130 fs/block_dev.c:1896
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688
 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45cc79
Code: 2d b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 fb b5 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fcd9452ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000008f80 RCX: 000000000045cc79
RDX: 0000000000000000 RSI: 0000000000001276 RDI: 0000000000000003
RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c
R13: 00007fff3d5466df R14: 00007fcd9452f9c0 R15: 000000000078bf0c

Allocated by task 16259:
 kmem_cache_alloc+0x122/0x370 mm/slab.c:3559
 __d_alloc+0x2b/0xa10 fs/dcache.c:1610
 d_alloc+0x4a/0x230 fs/dcache.c:1694
 d_alloc_parallel+0xeb/0x19e0 fs/dcache.c:2441
 __lookup_slow+0x18d/0x4a0 fs/namei.c:1655
 lookup_one_len+0x163/0x190 fs/namei.c:2544
 start_creating.part.0+0x62/0x160 fs/tracefs/inode.c:336
 start_creating fs/debugfs/inode.c:301 [inline]
 __debugfs_create_file+0xb8/0x4e0 fs/debugfs/inode.c:352
 do_blk_trace_setup+0x3a5/0xc30 kernel/trace/blktrace.c:542
 __blk_trace_setup+0xca/0x180 kernel/trace/blktrace.c:591
 blk_trace_ioctl+0x155/0x290 kernel/trace/blktrace.c:732
 blkdev_ioctl+0x112/0x1a7e block/ioctl.c:587
 block_ioctl+0xe9/0x130 fs/block_dev.c:1896
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688
 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 16262:
 __cache_free mm/slab.c:3503 [inline]
 kmem_cache_free+0x7f/0x260 mm/slab.c:3765
 __rcu_reclaim kernel/rcu/rcu.h:236 [inline]
 rcu_do_batch kernel/rcu/tree.c:2584 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2897 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2864 [inline]
 rcu_process_callbacks+0x8ff/0x18b0 kernel/rcu/tree.c:2881
 __do_softirq+0x26c/0x9a0 kernel/softirq.c:292

The buggy address belongs to the object at ffff8880417ef4a0
 which belongs to the cache dentry of size 288
The buggy address is located 64 bytes inside of
 288-byte region [ffff8880417ef4a0, ffff8880417ef5c0)
The buggy address belongs to the page:
page:ffffea000105fbc0 count:1 mapcount:0 mapping:ffff88821bc44c80 index:0xffff8880417efb80
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffffea00010c1748 ffffea00010c58c8 ffff88821bc44c80
raw: ffff8880417efb80 ffff8880417ef080 000000010000000a 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880417ef380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880417ef400: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
>ffff8880417ef480: fc fc fc fc fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff8880417ef500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880417ef580: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================
FAT-fs (loop3): bogus number of reserved sectors
FAT-fs (loop3): Can't find a valid FAT filesystem
FAT-fs (loop2): bogus number of FAT sectors
FAT-fs (loop2): Can't find a valid FAT filesystem