INFO: task syz-executor.5:25575 blocked for more than 143 seconds. Not tainted 5.1.0+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D29056 25575 19874 0x00004006 Call Trace: context_switch kernel/sched/core.c:2817 [inline] __schedule+0x7cb/0x1560 kernel/sched/core.c:3444 schedule+0xa8/0x260 kernel/sched/core.c:3508 exp_funnel_lock kernel/rcu/tree_exp.h:309 [inline] synchronize_rcu_expedited+0x54e/0x5b0 kernel/rcu/tree_exp.h:790 synchronize_net+0x3b/0x60 net/core/dev.c:9279 packet_release+0x806/0xbf0 net/packet/af_packet.c:3015 __sock_release+0xce/0x2a0 net/socket.c:607 sock_close+0x1b/0x30 net/socket.c:1279 __fput+0x2ff/0x890 fs/file_table.c:279 ____fput+0x16/0x20 fs/file_table.c:312 task_work_run+0x145/0x1c0 kernel/task_work.c:113 get_signal+0x1dda/0x2240 kernel/signal.c:2431 do_signal+0x87/0x1900 arch/x86/kernel/signal.c:815 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x58e/0x680 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459279 Code: Bad RIP value. RSP: 002b:00007f731e256c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002f RAX: fffffffffffffe00 RBX: 0000000000000003 RCX: 0000000000459279 RDX: 0000000000000000 RSI: 0000000020002940 RDI: 0000000000000003 RBP: 000000000075bfc0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f731e2576d4 R13: 00000000004c637f R14: 00000000004dae00 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1042: #0: 00000000d31053c0 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5148 3 locks held by rs:main Q:Reg/8945: #0: 000000009df1c341 (&rq->lock){-.-.}, at: idle_balance kernel/sched/fair.c:10083 [inline] #0: 000000009df1c341 (&rq->lock){-.-.}, at: pick_next_task_fair+0x120e/0x1990 kernel/sched/fair.c:7090 #1: 00000000d31053c0 (rcu_read_lock){....}, at: __update_idle_core+0x45/0x3f0 kernel/sched/fair.c:6087 #2: 000000004f3ec84b (&sb->s_type->i_mutex_key#10){+.+.}, at: inode_trylock include/linux/fs.h:798 [inline] #2: 000000004f3ec84b (&sb->s_type->i_mutex_key#10){+.+.}, at: ext4_file_write_iter+0x257/0x11c0 fs/ext4/file.c:232 1 lock held by rsyslogd/8947: #0: 00000000ab9564ea (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/9037: #0: 0000000043111722 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000f252948b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/9038: #0: 00000000da5cec48 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000088e0650f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/9039: #0: 00000000eae29205 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000068cf695 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/9040: #0: 000000005ed4869c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000007907da69 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/9041: #0: 00000000db21c369 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000006e169af6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/9042: #0: 00000000b45c734b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000009ca8a47a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/9043: #0: 0000000027aa6454 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000ee58be4c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.5/25575: #0: 000000000b43b7d1 (&sb->s_type->i_mutex_key#11){+.+.}, at: inode_lock include/linux/fs.h:778 [inline] #0: 000000000b43b7d1 (&sb->s_type->i_mutex_key#11){+.+.}, at: __sock_release+0x89/0x2a0 net/socket.c:606 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1042 Comm: khungtaskd Not tainted 5.1.0+ #1 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+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0x9b7/0xec0 kernel/hung_task.c:288 kthread+0x354/0x420 kernel/kthread.c:253 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60