tmpfs: No value for mount option './bus'
tmpfs: No value for mount option './bus'
tmpfs: No value for mount option './bus'
tmpfs: No value for mount option './bus'
==================================================================
BUG: KASAN: use-after-free in d_inode include/linux/dcache.h:516 [inline]
BUG: KASAN: use-after-free in relay_switch_subbuf+0x8cc/0x940 kernel/relay.c:761
Read of size 8 at addr ffff8880b1aa05d8 by task syz-executor.4/24552

CPU: 0 PID: 24552 Comm: syz-executor.4 Not tainted 4.19.211-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/0x2ef lib/dump_stack.c:118
 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354
 kasan_report mm/kasan/report.c:412 [inline]
 __asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433
 d_inode include/linux/dcache.h:516 [inline]
 relay_switch_subbuf+0x8cc/0x940 kernel/relay.c:761
 relay_reserve include/linux/relay.h:261 [inline]
 trace_note+0x5eb/0x750 kernel/trace/blktrace.c:96
 trace_note_tsk kernel/trace/blktrace.c:127 [inline]
 __blk_add_trace+0xb86/0xe20 kernel/trace/blktrace.c:267
 blk_add_trace_plug+0xfe/0x240 kernel/trace/blktrace.c:1000
 trace_block_plug include/trace/events/block.h:456 [inline]
 blk_mq_make_request+0x14b7/0x1c00 block/blk-mq.c:1902
 generic_make_request+0x613/0xdf0 block/blk-core.c:2467
 submit_bio+0xb1/0x430 block/blk-core.c:2576
 dio_bio_submit fs/direct-io.c:481 [inline]
 do_blockdev_direct_IO fs/direct-io.c:1360 [inline]
 __blockdev_direct_IO+0xa762/0xef40 fs/direct-io.c:1419
 ext4_direct_IO_write fs/ext4/inode.c:3777 [inline]
 ext4_direct_IO+0xae4/0x1c50 fs/ext4/inode.c:3915
 generic_file_direct_write+0x208/0x4a0 mm/filemap.c:3073
 __generic_file_write_iter+0x2d0/0x610 mm/filemap.c:3252
 ext4_file_write_iter+0x2fe/0xf20 fs/ext4/file.c:272
 call_write_iter include/linux/fs.h:1821 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x51b/0x770 fs/read_write.c:487
 vfs_write+0x1f3/0x540 fs/read_write.c:549
 ksys_write+0x12b/0x2a0 fs/read_write.c:599
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f9eb108ee99
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
tmpfs: No value for mount option './bus'
RSP: 002b:00007f9eafa04168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
tmpfs: No value for mount option './bus'
RAX: ffffffffffffffda RBX: 00007f9eb11a1f60 RCX: 00007f9eb108ee99
RDX: 000000000004ea00 RSI: 0000000020000200 RDI: 0000000000000006
RBP: 00007f9eb10e8ff1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffdffe202ef R14: 00007f9eafa04300 R15: 0000000000022000

tmpfs: No value for mount option './bus'
Allocated by task 23552:
 kmem_cache_alloc+0x122/0x370 mm/slab.c:3559
 __d_alloc+0x2b/0xa10 fs/dcache.c:1612
 d_alloc+0x4a/0x230 fs/dcache.c:1696
 d_alloc_parallel+0xeb/0x19e0 fs/dcache.c:2443
 __lookup_slow+0x18d/0x4a0 fs/namei.c:1655
tmpfs: No value for mount option './bus'
 lookup_one_len+0x163/0x190 fs/namei.c:2544
 start_creating+0xc9/0x220 fs/debugfs/inode.c:313
 __debugfs_create_file+0x5e/0x480 fs/debugfs/inode.c:352
 kvm_create_vm_debugfs arch/x86/kvm/../../../virt/kvm/kvm_main.c:650 [inline]
 kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:3475 [inline]
 kvm_dev_ioctl+0xa2b/0x16e0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3502
tmpfs: No value for mount option './bus'
 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

tmpfs: No value for mount option './bus'
Freed by task 9:
 __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+0x265/0x980 kernel/softirq.c:292
tmpfs: No value for mount option './bus'

The buggy address belongs to the object at ffff8880b1aa0580
 which belongs to the cache dentry of size 288
The buggy address is located 88 bytes inside of
 288-byte region [ffff8880b1aa0580, ffff8880b1aa06a0)
The buggy address belongs to the page:
page:ffffea0002c6a800 count:1 mapcount:0 mapping:ffff88813be45200 index:0xffff8880b1aa02c0
tmpfs: No value for mount option './bus'
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffffea0002c6a748 ffffea0002c6a8c8 ffff88813be45200
raw: ffff8880b1aa02c0 ffff8880b1aa0000 0000000100000008 0000000000000000
tmpfs: No value for mount option './bus'
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880b1aa0480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880b1aa0500: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
>ffff8880b1aa0580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
 ffff8880b1aa0600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
tmpfs: No value for mount option './bus'
 ffff8880b1aa0680: fb fb fb fb fc fc fc fc fc fc fc fc 00 00 00 00
==================================================================