sch_tbf: burst 8 is lower than device veth315 mtu (1514) ! sch_tbf: burst 8 is lower than device veth251 mtu (1514) ! sch_tbf: burst 8 is lower than device veth315 mtu (1514) ! sch_tbf: burst 8 is lower than device veth251 mtu (1514) ! INFO: task syz-executor.0:3843 blocked for more than 140 seconds. Not tainted 4.14.229-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28184 3843 3834 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 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:588 [inline] rwsem_down_write_failed+0x343/0x6d0 kernel/locking/rwsem-xadd.c:617 call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:105 __down_write arch/x86/include/asm/rwsem.h:126 [inline] down_write+0x4f/0x90 kernel/locking/rwsem.c:56 grab_super+0x55/0x140 fs/super.c:373 sget_userns+0x2b1/0xc10 fs/super.c:504 sget+0xd1/0x110 fs/super.c:572 mount_bdev+0xcd/0x360 fs/super.c:1107 mount_fs+0x92/0x2a0 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0xe53/0x2a00 fs/namespace.c:2879 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3072 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x466459 RSP: 002b:00007fdad3976188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 0000000020000000 RSI: 0000000020000180 RDI: 0000000020000380 RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000 R10: 0000000001008800 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffce0a46baf R14: 00007fdad3976300 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/7774: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0x1fb/0x2b0 fs/file.c:769 2 locks held by syz-executor.0/3843: #0: (&bdev->bd_fsfreeze_mutex){+.+.}, at: [] mount_bdev+0x71/0x360 fs/super.c:1101 #1: (&type->s_umount_key#108){++++}, at: [] grab_super+0x55/0x140 fs/super.c:373 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1534 Comm: khungtaskd Not tainted 4.14.229-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: 4622 Comm: systemd-journal Not tainted 4.14.229-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880a178e0c0 task.stack: ffff8880a1790000 RIP: 0010:__lock_release kernel/locking/lockdep.c:3767 [inline] RIP: 0010:lock_release+0x227/0x870 kernel/locking/lockdep.c:4017 RSP: 0018:ffff8880a17979d0 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 1ffff110142f2f3d RCX: 1ffffffff127a2dc RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff8880a178e944 RBP: ffffffff8bfbb960 R08: ffffffff8bfbb948 R09: 0000000000000001 R10: 0000000000000000 R11: ffff8880a178e0c0 R12: ffffffff8319a080 R13: ffffffff8bebbd40 R14: ffff8880a178e0c0 R15: 0000000000000001 FS: 00007f57dc2e38c0(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f57d9150028 CR3: 00000000a17f8000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_unlock_irqrestore+0x1b/0xe0 kernel/locking/spinlock.c:192 debug_object_activate+0x1a0/0x490 lib/debugobjects.c:464 debug_rcu_head_queue kernel/rcu/rcu.h:152 [inline] __call_rcu.constprop.0+0x31/0x7d0 kernel/rcu/tree.c:3050 file_free fs/file_table.c:56 [inline] put_filp+0x75/0x90 fs/file_table.c:308 path_openat+0x6ce/0x2970 fs/namei.c:3581 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f57db872840 RSP: 002b:00007ffd0a82aee8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007ffd0a82b1f0 RCX: 00007f57db872840 RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 0000561100be67b0 RBP: 000000000000000d R08: 0000000000000000 R09: 00000000ffffffff R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000561100be2040 R14: 00007ffd0a82b1b0 R15: 0000561100bef160 Code: 0f b6 14 02 4c 89 e8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 46 05 00 00 44 89 f8 0b 05 42 05 aa 0a 0f 84 3e 04 00 00 44 89 fa <48> 89 ee 4c 89 f7 48 8d 4c 24 38 e8 c9 71 ff ff 48 85 c0 48 89