Bluetooth: hci0 command 0x0406 tx timeout Bluetooth: hci4 command 0x0406 tx timeout Bluetooth: hci2 command 0x0406 tx timeout Bluetooth: hci1 command 0x0406 tx timeout Bluetooth: hci3 command 0x0406 tx timeout INFO: task syz-executor.1:11883 blocked for more than 140 seconds. Not tainted 4.14.275-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D30296 11883 8006 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline] rwsem_down_read_failed+0x1e6/0x350 kernel/locking/rwsem-xadd.c:309 call_rwsem_down_read_failed+0x14/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:66 [inline] down_read+0x44/0x80 kernel/locking/rwsem.c:26 __get_super.part.0+0x271/0x390 fs/super.c:678 __get_super include/linux/spinlock.h:317 [inline] get_super+0x2b/0x50 fs/super.c:707 fsync_bdev+0x14/0xc0 fs/block_dev.c:495 blkdev_flushbuf block/ioctl.c:430 [inline] blkdev_ioctl+0x883/0x1830 block/ioctl.c:514 block_ioctl+0xd9/0x120 fs/block_dev.c:1893 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 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+0x46/0xbb RIP: 0033:0x7fb6c8e4d0e9 RSP: 002b:00007fb6c77a1168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fb6c8f60030 RCX: 00007fb6c8e4d0e9 RDX: 0000000000000000 RSI: 0000000000001261 RDI: 0000000000000003 RBP: 00007fb6c8ea708d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffbcff766f R14: 00007fb6c77a1300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/1533: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 1 lock held by syz-executor.1/11883: #0: (&type->s_umount_key#77){.+.+}, at: [] __get_super.part.0+0x271/0x390 fs/super.c:678 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1533 Comm: khungtaskd Not tainted 4.14.275-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5b9/0xb40 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3516 Comm: kworker/u4:4 Not tainted 4.14.275-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker task: ffff8880a9142480 task.stack: ffff8880a9148000 RIP: 0010:__lock_acquire+0x206/0x3f20 kernel/locking/lockdep.c:3373 RSP: 0018:ffff8880a914faa8 EFLAGS: 00000802 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 1ffffffff11eefc1 RSI: 0000000000000000 RDI: ffffffff88f77e08 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: ffff8880a9142480 R12: ffffffff88f77e00 R13: 0000000000000000 R14: 0000000000000000 R15: ffffffff8bed0d40 FS: 0000000000000000(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6984eae000 CR3: 00000000a1678000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 rcu_lock_acquire include/linux/rcupdate.h:242 [inline] rcu_read_lock include/linux/rcupdate.h:629 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:418 [inline] batadv_nc_worker+0x124/0xc50 net/batman-adv/network-coding.c:728 process_one_work+0x793/0x14a0 kernel/workqueue.c:2117 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2251 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: c7 2f 8b 0f 84 5f ff ff ff 83 fe 01 0f 87 62 ff ff ff 48 b8 00 00 00 00 00 fc ff df 41 89 f6 4b 8d 7c f4 08 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 5e 2a 00 00 4b 8b 44 f4 08 48 85 c0 0f 84 31 ---------------- Code disassembly (best guess), 3 bytes skipped: 0: 0f 84 5f ff ff ff je 0xffffff65 6: 83 fe 01 cmp $0x1,%esi 9: 0f 87 62 ff ff ff ja 0xffffff71 f: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 16: fc ff df 19: 41 89 f6 mov %esi,%r14d 1c: 4b 8d 7c f4 08 lea 0x8(%r12,%r14,8),%rdi 21: 48 89 fa mov %rdi,%rdx 24: 48 c1 ea 03 shr $0x3,%rdx * 28: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction 2c: 0f 85 5e 2a 00 00 jne 0x2a90 32: 4b 8b 44 f4 08 mov 0x8(%r12,%r14,8),%rax 37: 48 85 c0 test %rax,%rax 3a: 0f .byte 0xf 3b: 84 31 test %dh,(%rcx)