INFO: task syz-executor.0:10773 blocked for more than 140 seconds. Not tainted 4.14.277-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D29296 10773 7977 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 schedule_timeout+0x80a/0xe90 kernel/time/timer.c:1724 do_wait_for_common kernel/sched/completion.c:91 [inline] __wait_for_common kernel/sched/completion.c:112 [inline] wait_for_common+0x272/0x430 kernel/sched/completion.c:123 usb_start_wait_urb+0x125/0x440 drivers/usb/core/message.c:61 usb_bulk_msg+0x1f6/0x500 drivers/usb/core/message.c:252 proc_bulk+0x331/0x6d0 drivers/usb/core/devio.c:1223 usbdev_do_ioctl+0x5b0/0x2b70 drivers/usb/core/devio.c:2449 usbdev_ioctl+0x21/0x30 drivers/usb/core/devio.c:2599 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: 0033:0x7f746ae1a0e9 RSP: 002b:00007f746978f168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f746af2cf60 RCX: 00007f746ae1a0e9 RDX: 0000000020000180 RSI: 00000000c0185502 RDI: 0000000000000003 RBP: 00007f746ae7408d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd997c261f R14: 00007f746978f300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/1534: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 1 lock held by in:imklog/7682: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0x1fb/0x2b0 fs/file.c:819 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1534 Comm: khungtaskd Not tainted 4.14.277-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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 9192 Comm: kworker/u4:5 Not tainted 4.14.277-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker task: ffff88805c2c2680 task.stack: ffff88805c2d0000 RIP: 0010:__lock_acquire+0x210/0x3f20 kernel/locking/lockdep.c:3373 RSP: 0018:ffff88805c2d7aa8 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 1ffffffff11eefd9 RSI: 0000000000000000 RDI: ffffffff88f77ec8 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: ffff88805c2c2680 R12: ffffffff88f77ec0 R13: 0000000000000000 R14: 0000000000000000 R15: ffffffff8bed1d40 FS: 0000000000000000(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6585647018 CR3: 0000000095b63000 CR4: 00000000003406e0 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: 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 ff ff ff f0 ff 80 38 01 00 00 ---------------- Code disassembly (best guess): 0: fe 01 incb (%rcx) 2: 0f 87 62 ff ff ff ja 0xffffff6a 8: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax f: fc ff df 12: 41 89 f6 mov %esi,%r14d 15: 4b 8d 7c f4 08 lea 0x8(%r12,%r14,8),%rdi 1a: 48 89 fa mov %rdi,%rdx 1d: 48 c1 ea 03 shr $0x3,%rdx 21: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 25: 0f 85 5e 2a 00 00 jne 0x2a89 * 2b: 4b 8b 44 f4 08 mov 0x8(%r12,%r14,8),%rax <-- trapping instruction 30: 48 85 c0 test %rax,%rax 33: 0f 84 31 ff ff ff je 0xffffff6a 39: f0 ff 80 38 01 00 00 lock incl 0x138(%rax)