block nbd0: Receive control failed (result -107) block nbd0: shutting down sockets block nbd0: Receive control failed (result -107) block nbd0: shutting down sockets INFO: task syz-executor.3:10664 blocked for more than 140 seconds. Not tainted 4.14.206-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28768 10664 8049 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x80a/0xe90 kernel/time/timer.c:1731 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 flush_workqueue+0x3ce/0x1310 kernel/workqueue.c:2676 nbd_start_device_ioctl drivers/block/nbd.c:1254 [inline] __nbd_ioctl drivers/block/nbd.c:1325 [inline] nbd_ioctl+0x49d/0xa80 drivers/block/nbd.c:1365 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x540/0x1830 block/ioctl.c:594 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: 0033:0x45deb9 RSP: 002b:00007f36b1837c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000012f00 RCX: 000000000045deb9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006 RBP: 000000000118bf58 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c R13: 00007ffd7517495f R14: 00007f36b18389c0 R15: 000000000118bf2c Showing all locks held in the system: 1 lock held by khungtaskd/1531: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 1 lock held by in:imklog/7720: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0x1fb/0x2b0 fs/file.c:769 2 locks held by agetty/7967: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e3/0x1680 drivers/tty/n_tty.c:2156 3 locks held by kworker/u5:7/8083: #0: ("knbd%d-recv"nbd->index){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2087 #1: ((&args->work)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2091 #2: (sk_lock-AF_AX25){+.+.}, at: [] lock_sock include/net/sock.h:1471 [inline] #2: (sk_lock-AF_AX25){+.+.}, at: [] ax25_recvmsg+0xa8/0x7a0 net/ax25/af_ax25.c:1630 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1531 Comm: khungtaskd Not tainted 4.14.206-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+0x1b2/0x283 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x17f 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: 4617 Comm: systemd-journal Not tainted 4.14.206-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880a1aac680 task.stack: ffff8880a1ab0000 RIP: 0010:free_uid+0x243/0x330 kernel/user.c:169 RSP: 0018:ffff8880a1ab7de8 EFLAGS: 00000006 RAX: ffff8880a1aac680 RBX: ffff8880aff81ea8 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff88f44d20 RDI: ffffffff88f44c80 RBP: ffffffff88f44c80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000297 R13: ffff8880aff81ea0 R14: 00000000ffffff9c R15: 0000562c26bd59a3 FS: 00007f9bfb5b98c0(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9bf8344000 CR3: 00000000a1efc000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: put_cred_rcu+0x1e8/0x300 kernel/cred.c:124 __put_cred+0x1a1/0x210 kernel/cred.c:151 put_cred include/linux/cred.h:271 [inline] SYSC_faccessat fs/open.c:444 [inline] SyS_faccessat+0x52a/0x680 fs/open.c:353 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f9bfa8759c7 RSP: 002b:00007ffd768722a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffd768752d0 RCX: 00007f9bfa8759c7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000562c26bd59a3 RBP: 00007ffd768723f0 R08: 0000562c26bcb3e5 R09: 0000000000000018 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000562c28a918a0 R15: 00007ffd768728e0 Code: 02 00 0f 85 cc 00 00 00 48 8b 7d 40 e8 47 6a ad 01 48 8b 3d 00 71 f9 09 48 89 ee e8 28 ac 4c 00 5b 5d 41 5c 41 5d e9 5d 12 23 00 58 12 23 00 e8 c3 61 0e 00 48 c7 c0 88 91 f0 88 48 ba 00 00