INFO: task syz-executor0:30634 blocked for more than 140 seconds. Not tainted 4.20.0-rc3+ #311 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D22776 30634 6048 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472 schedule+0xfe/0x460 kernel/sched/core.c:3516 exp_funnel_lock kernel/rcu/tree_exp.h:319 [inline] _synchronize_rcu_expedited.constprop.58+0x8df/0x9d0 kernel/rcu/tree_exp.h:620 synchronize_rcu_expedited+0x27/0xa0 kernel/rcu/tree_exp.h:758 synchronize_net+0x3b/0x60 net/core/dev.c:9075 packet_set_ring+0x286/0x1da0 net/packet/af_packet.c:4339 packet_setsockopt+0x16ef/0x23b0 net/packet/af_packet.c:3649 __sys_setsockopt+0x1ba/0x3c0 net/socket.c:1902 __do_sys_setsockopt net/socket.c:1913 [inline] __se_sys_setsockopt net/socket.c:1910 [inline] __x64_sys_setsockopt+0xbe/0x150 net/socket.c:1910 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: 83 c4 18 c3 e8 d8 64 00 00 48 8b 04 24 48 8b 4c 24 08 48 89 01 e8 d7 2d fc ff e8 22 7a fc ff b8 02 00 00 00 48 8d 0d 2a 61 0c <01> 87 01 8b 05 22 61 0c 01 83 f8 01 0f 85 8a 00 00 00 b8 01 00 00 RSP: 002b:00007fdc8d932c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000457569 RDX: 000000000000000d RSI: 0000000000000107 RDI: 0000000000000004 RBP: 000000000072bfa0 R08: 000000000000001c R09: 0000000000000000 R10: 00000000200003c0 R11: 0000000000000246 R12: 00007fdc8d9336d4 R13: 00000000004c4989 R14: 00000000004d8230 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1020: #0: 00000000867839b2 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 2 locks held by rsyslogd/5916: #0: 00000000c58d62d2 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 #1: 00000000b2f78cf2 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1126 [inline] #1: 00000000b2f78cf2 (&rq->lock){-.-.}, at: __schedule+0x236/0x21d0 kernel/sched/core.c:3410 2 locks held by getty/6007: #0: 00000000cbd4490e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000d54a8dab (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6008: #0: 000000009f9ebb9e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000493d8a94 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6009: #0: 00000000fefb5565 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000165da412 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6010: #0: 00000000988ac123 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000c7a062cf (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6011: #0: 0000000016665db3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000005841ac23 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6012: #0: 000000009974857b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000003033d0c2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6013: #0: 0000000045aa1a3d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000cad3f3f7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 1 lock held by syz-executor0/30634: #0: 00000000bad49438 (sk_lock-AF_PACKET){+.+.}, at: lock_sock include/net/sock.h:1492 [inline] #0: 00000000bad49438 (sk_lock-AF_PACKET){+.+.}, at: packet_setsockopt+0x602/0x23b0 net/packet/af_packet.c:3632 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1020 Comm: khungtaskd Not tainted 4.20.0-rc3+ #311 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+0x244/0x39d lib/dump_stack.c:113 nmi_cpu_backtrace.cold.2+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1e8/0x22a 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:205 [inline] watchdog+0xb51/0x1060 kernel/hung_task.c:289 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57