==================================================================
BUG: KASAN: use-after-free in debugfs_remove+0x10d/0x130 fs/debugfs/inode.c:687
Read of size 8 at addr ffff888060b8b040 by task syz-executor.0/11319

CPU: 0 PID: 11319 Comm: syz-executor.0 Not tainted 4.19.67 #41
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+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report mm/kasan/report.c:412 [inline]
 kasan_report.cold+0x8c/0x2ba mm/kasan/report.c:396
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 debugfs_remove+0x10d/0x130 fs/debugfs/inode.c:687
 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_ioctl+0x239/0x300 kernel/trace/blktrace.c:730
 blkdev_ioctl+0x126/0x1ab6 block/ioctl.c:587
 block_ioctl+0xee/0x130 fs/block_dev.c:1891
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459829
Code: fd b7 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f205a63cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459829
RDX: 0000000000000000 RSI: 0000000000001276 RDI: 0000000000000007
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f205a63d6d4
R13: 00000000004c0f14 R14: 00000000004d40f8 R15: 00000000ffffffff

Allocated by task 11296:
 save_stack+0x45/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc mm/kasan/kasan.c:553 [inline]
 kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:531
 kasan_slab_alloc+0xf/0x20 mm/kasan/kasan.c:490
 kmem_cache_alloc+0x12e/0x700 mm/slab.c:3559
 __d_alloc+0x2e/0x9c0 fs/dcache.c:1610
 d_alloc+0x4d/0x280 fs/dcache.c:1694
 d_alloc_parallel+0xf4/0x1bb0 fs/dcache.c:2441
 __lookup_slow+0x1ab/0x500 fs/namei.c:1654
 lookup_one_len+0x16d/0x1a0 fs/namei.c:2543
 start_creating fs/debugfs/inode.c:313 [inline]
 start_creating+0xbf/0x1e0 fs/debugfs/inode.c:289
 __debugfs_create_file+0x65/0x400 fs/debugfs/inode.c:352
 debugfs_create_file+0x5a/0x70 fs/debugfs/inode.c:404
 do_blk_trace_setup+0x376/0xb90 kernel/trace/blktrace.c:528
 __blk_trace_setup+0xe3/0x190 kernel/trace/blktrace.c:577
 blk_trace_ioctl+0x170/0x300 kernel/trace/blktrace.c:716
 blkdev_ioctl+0x126/0x1ab6 block/ioctl.c:587
 block_ioctl+0xee/0x130 fs/block_dev.c:1891
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 18:
 save_stack+0x45/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3503 [inline]
 kmem_cache_free+0x86/0x260 mm/slab.c:3765
 __d_free+0x20/0x30 fs/dcache.c:257
 __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+0xba0/0x1a30 kernel/rcu/tree.c:2881
 __do_softirq+0x25c/0x921 kernel/softirq.c:292

The buggy address belongs to the object at ffff888060b8b000
 which belongs to the cache dentry(17:syz0) of size 288
The buggy address is located 64 bytes inside of
 288-byte region [ffff888060b8b000, ffff888060b8b120)
The buggy address belongs to the page:
page:ffffea000182e2c0 count:1 mapcount:0 mapping:ffff88809b1edc40 index:0x0
flags: 0x1fffc0000000100(slab)
raw: 01fffc0000000100 ffffea00023f6508 ffffea0000f1b848 ffff88809b1edc40
raw: 0000000000000000 ffff888060b8b000 000000010000000b ffff8880a6912640
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff8880a6912640

Memory state around the buggy address:
 ffff888060b8af00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888060b8af80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888060b8b000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff888060b8b080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888060b8b100: fb fb fb fb fc fc fc fc fc fc fc fc fb fb fb fb
==================================================================
SELinux: unrecognized netlink message: protocol=4 nlmsg_type=0 sclass=netlink_tcpdiag_socket pig=11332 comm=syz-executor.1