INFO: task syz-executor.5:18990 blocked for more than 143 seconds. Not tainted 5.2.0+ #33 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D26744 18990 8016 0x00004004 Call Trace: context_switch /kernel/sched/core.c:3254 [inline] __schedule+0x66f/0x9f0 /kernel/sched/core.c:3880 schedule+0x131/0x1e0 /kernel/sched/core.c:3944 exp_funnel_lock /kernel/rcu/tree_exp.h:308 [inline] synchronize_rcu_expedited+0x5b5/0x680 /kernel/rcu/tree_exp.h:816 synchronize_net+0x3b/0x50 /net/core/dev.c:9259 packet_release+0x943/0xbc0 /net/packet/af_packet.c:3033 __sock_release /net/socket.c:586 [inline] sock_close+0xe1/0x260 /net/socket.c:1264 __fput+0x2e4/0x740 /fs/file_table.c:280 ____fput+0x15/0x20 /fs/file_table.c:313 task_work_run+0x17e/0x1b0 /kernel/task_work.c:113 tracehook_notify_resume /./include/linux/tracehook.h:185 [inline] exit_to_usermode_loop /arch/x86/entry/common.c:163 [inline] prepare_exit_to_usermode+0x459/0x580 /arch/x86/entry/common.c:194 syscall_return_slowpath+0x110/0x450 /arch/x86/entry/common.c:274 do_syscall_64+0x126/0x140 /arch/x86/entry/common.c:299 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x413501 Code: 39 0f 87 d1 03 00 00 49 89 f2 45 31 db 45 31 e4 eb 27 4d 8d 6b 08 44 0f b6 36 49 89 cf 4c 89 d9 49 d3 e6 48 83 f9 40 4c 89 f9 <4d> 19 ff 4d 21 f7 4d 09 fc 48 ff c6 4d 89 eb 4d 39 cb 72 d4 4c 89 RSP: 002b:00007fffc6626910 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000413501 RDX: 0000001b30b20000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000001 R08: ffffffff810081ee R09: 000000007a1fa103 R10: 00007fffc66269f0 R11: 0000000000000293 R12: 000000000075c9a0 R13: 000000000075c9a0 R14: 0000000000760d00 R15: ffffffffffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1050: #0: 000000009e52911f (rcu_read_lock){....}, at: rcu_lock_acquire+0x4/0x30 /./include/linux/rcupdate.h:207 2 locks held by getty/7919: #0: 00000000026eeea1 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 /drivers/tty/tty_ldisc.c:272 #1: 00000000d419fd7c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 /drivers/tty/n_tty.c:2156 2 locks held by getty/7920: #0: 00000000efe71443 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 /drivers/tty/tty_ldisc.c:272 #1: 000000007bf62bf3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 /drivers/tty/n_tty.c:2156 2 locks held by getty/7921: #0: 00000000c9aba656 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 /drivers/tty/tty_ldisc.c:272 #1: 0000000051a95fd1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 /drivers/tty/n_tty.c:2156 2 locks held by getty/7922: #0: 000000007a9306ef (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 /drivers/tty/tty_ldisc.c:272 #1: 00000000bcf05f0f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 /drivers/tty/n_tty.c:2156 2 locks held by getty/7923: #0: 00000000beaa2ec6 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 /drivers/tty/tty_ldisc.c:272 #1: 000000002c9d52d9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 /drivers/tty/n_tty.c:2156 2 locks held by getty/7924: #0: 00000000f98d8419 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 /drivers/tty/tty_ldisc.c:272 #1: 00000000d5189571 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 /drivers/tty/n_tty.c:2156 2 locks held by getty/7925: #0: 000000001f08e680 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 /drivers/tty/tty_ldisc.c:272 #1: 00000000805dc210 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ee/0x1c80 /drivers/tty/n_tty.c:2156 1 lock held by syz-executor.5/18990: #0: 0000000099316c23 (&sb->s_type->i_mutex_key#11){+.+.}, at: inode_lock /./include/linux/fs.h:778 [inline] #0: 0000000099316c23 (&sb->s_type->i_mutex_key#11){+.+.}, at: __sock_release /net/socket.c:585 [inline] #0: 0000000099316c23 (&sb->s_type->i_mutex_key#11){+.+.}, at: sock_close+0x9e/0x260 /net/socket.c:1264 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1050 Comm: khungtaskd Not tainted 5.2.0+ #33 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+0x1d8/0x2f8 /lib/dump_stack.c:113 nmi_cpu_backtrace+0xaf/0x1a0 /lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x174/0x290 /lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x10/0x20 /arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace+0x17/0x20 /./include/linux/nmi.h:146 check_hung_uninterruptible_tasks /kernel/hung_task.c:205 [inline] watchdog+0xbb9/0xbd0 /kernel/hung_task.c:289 kthread+0x332/0x350 /kernel/kthread.c:255 ret_from_fork+0x24/0x30 /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+0xe/0x10 /./arch/x86/include/asm/irqflags.h:60