INFO: task syz-executor.4:31718 blocked for more than 143 seconds. Not tainted 5.1.0+ #5 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28560 31718 946 0x00004006 Call Trace: context_switch kernel/sched/core.c:2817 [inline] __schedule+0x7d1/0x1580 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+0xd3/0x2b0 net/socket.c:607 sock_close+0x1b/0x30 net/socket.c:1279 __fput+0x302/0x890 fs/file_table.c:279 ____fput+0x16/0x20 fs/file_table.c:312 task_work_run+0x14a/0x1c0 kernel/task_work.c:113 get_signal+0x1ddd/0x2250 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:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:276 [inline] do_syscall_64+0x57e/0x670 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458da9 Code: Bad RIP value. RSP: 002b:00007f2cfd965c78 EFLAGS: 00000246 ORIG_RAX: 000000000000010f RAX: 0000000000000001 RBX: 0000000000000005 RCX: 0000000000458da9 RDX: 0000000020000080 RSI: 0000000000000001 RDI: 0000000020000040 RBP: 000000000073c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2cfd9666d4 R13: 00000000004c57cb R14: 00000000004d9cc8 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1042: #0: 000000001c680a87 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5148 1 lock held by rsyslogd/7718: #0: 000000006c75d639 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/7808: #0: 000000000ba43fae (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000cef16663 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7809: #0: 000000004c0cc7b4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000099db63b1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7810: #0: 000000009d3e6f52 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000003a648452 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7811: #0: 000000009337de59 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000001bd9d6ca (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7812: #0: 000000009fd96dec (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000004d5a5a60 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7813: #0: 000000000b14746b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000fe4982b2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7814: #0: 000000003c9d0121 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000ea1924e1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.4/31718: #0: 00000000573b869f (&sb->s_type->i_mutex_key#11){+.+.}, at: inode_lock include/linux/fs.h:778 [inline] #0: 00000000573b869f (&sb->s_type->i_mutex_key#11){+.+.}, at: __sock_release+0x89/0x2b0 net/socket.c:606 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1042 Comm: khungtaskd Not tainted 5.1.0+ #5 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+0x357/0x430 kernel/kthread.c:253 ret_from_fork+0x3a/0x50 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+0x2/0x10 arch/x86/include/asm/irqflags.h:57