INFO: task syz-executor1:815 blocked for more than 140 seconds. Not tainted 4.19.0-rc2+ #52 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D23176 815 5359 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473 schedule+0xfe/0x460 kernel/sched/core.c:3517 exp_funnel_lock kernel/rcu/tree_exp.h:320 [inline] _synchronize_rcu_expedited+0xc68/0xfd0 kernel/rcu/tree_exp.h:667 synchronize_rcu_expedited+0x35/0xb0 kernel/rcu/tree_exp.h:795 synchronize_net+0x3b/0x60 net/core/dev.c:9012 packet_release+0x926/0xda0 net/packet/af_packet.c:3006 __sock_release+0xd7/0x250 net/socket.c:579 sock_close+0x19/0x20 net/socket.c:1139 __fput+0x385/0xa30 fs/file_table.c:278 ____fput+0x15/0x20 fs/file_table.c:309 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x410e91 Code: ff 48 8d 05 59 89 0a 01 48 89 84 24 c0 00 00 00 48 8b ac 24 98 00 00 00 48 81 c4 a0 00 00 00 c3 e8 14 90 01 00 0f 0b e8 0d 90 <01> 00 0f 0b e8 06 90 01 00 0f 0b e8 ff 8f 01 00 0f 0b 48 8d 05 36 RSP: 002b:00007ffe5f940220 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000410e91 RDX: 0000000000000000 RSI: 0000000000730518 RDI: 0000000000000004 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffffffffffff R10: 00000000009300a0 R11: 0000000000000293 R12: 0000000000000002 R13: 0000000000060e07 R14: 00000000000004d5 R15: badc0ffeebadface INFO: task syz-executor2:823 blocked for more than 140 seconds. Not tainted 4.19.0-rc2+ #52 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D23400 823 5360 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473 schedule+0xfe/0x460 kernel/sched/core.c:3517 exp_funnel_lock kernel/rcu/tree_exp.h:320 [inline] _synchronize_rcu_expedited+0xc68/0xfd0 kernel/rcu/tree_exp.h:667 synchronize_rcu_expedited+0x35/0xb0 kernel/rcu/tree_exp.h:795 synchronize_net+0x3b/0x60 net/core/dev.c:9012 packet_release+0x926/0xda0 net/packet/af_packet.c:3006 __sock_release+0xd7/0x250 net/socket.c:579 sock_close+0x19/0x20 net/socket.c:1139 __fput+0x385/0xa30 fs/file_table.c:278 ____fput+0x15/0x20 fs/file_table.c:309 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x410e91 Code: ff 48 8d 05 59 89 0a 01 48 89 84 24 c0 00 00 00 48 8b ac 24 98 00 00 00 48 81 c4 a0 00 00 00 c3 e8 14 90 01 00 0f 0b e8 0d 90 <01> 00 0f 0b e8 06 90 01 00 0f 0b e8 ff 8f 01 00 0f 0b 48 8d 05 36 RSP: 002b:00007ffd1b46e4e0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000410e91 RDX: 0000000000000000 RSI: 0000000000730518 RDI: 0000000000000004 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffffffffffff R10: 00000000009300a0 R11: 0000000000000293 R12: 0000000000000002 R13: 0000000000060de2 R14: 00000000000004f2 R15: badc0ffeebadface INFO: task syz-executor3:826 blocked for more than 140 seconds. Not tainted 4.19.0-rc2+ #52 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D23400 826 5361 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473 schedule+0xfe/0x460 kernel/sched/core.c:3517 exp_funnel_lock kernel/rcu/tree_exp.h:320 [inline] _synchronize_rcu_expedited+0xc68/0xfd0 kernel/rcu/tree_exp.h:667 synchronize_rcu_expedited+0x35/0xb0 kernel/rcu/tree_exp.h:795 synchronize_net+0x3b/0x60 net/core/dev.c:9012 packet_release+0x926/0xda0 net/packet/af_packet.c:3006 __sock_release+0xd7/0x250 net/socket.c:579 sock_close+0x19/0x20 net/socket.c:1139 __fput+0x385/0xa30 fs/file_table.c:278 ____fput+0x15/0x20 fs/file_table.c:309 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x410e91 Code: ff 48 8d 05 59 89 0a 01 48 89 84 24 c0 00 00 00 48 8b ac 24 98 00 00 00 48 81 c4 a0 00 00 00 c3 e8 14 90 01 00 0f 0b e8 0d 90 <01> 00 0f 0b e8 06 90 01 00 0f 0b e8 ff 8f 01 00 0f 0b 48 8d 05 36 RSP: 002b:00007ffc7c8009f0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000410e91 RDX: 0000000000000000 RSI: 0000000000730518 RDI: 0000000000000004 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffffffffffff R10: 00000000009300a0 R11: 0000000000000293 R12: 0000000000000002 R13: 0000000000060ded R14: 000000000000051c R15: badc0ffeebadface Showing all locks held in the system: 1 lock held by khungtaskd/985: #0: 00000000e1156992 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4436 1 lock held by rsyslogd/5221: #0: 00000000b144b385 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5312: #0: 00000000cc58f9c9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000f7db70cf (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5313: #0: 0000000038a2b0dc (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000007d57b9cf (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5314: #0: 000000000d3ac67b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000ad9348ac (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5315: #0: 0000000087c89046 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000ee92f35f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5316: #0: 00000000d76ca9e1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000006977c99f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5317: #0: 00000000e0608d2e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000f90ae13b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5318: #0: 000000001dc8ea77 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000008985db90 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 1 lock held by syz-executor1/815: #0: 00000000403f514f (&sb->s_type->i_mutex_key#12){+.+.}, at: inode_lock include/linux/fs.h:738 [inline] #0: 00000000403f514f (&sb->s_type->i_mutex_key#12){+.+.}, at: __sock_release+0x8b/0x250 net/socket.c:578 1 lock held by syz-executor2/823: #0: 00000000128bb27e (&sb->s_type->i_mutex_key#12){+.+.}, at: inode_lock include/linux/fs.h:738 [inline] #0: 00000000128bb27e (&sb->s_type->i_mutex_key#12){+.+.}, at: __sock_release+0x8b/0x250 net/socket.c:578 1 lock held by syz-executor3/826: #0: 00000000697a54e4 (&sb->s_type->i_mutex_key#12){+.+.}, at: inode_lock include/linux/fs.h:738 [inline] #0: 00000000697a54e4 (&sb->s_type->i_mutex_key#12){+.+.}, at: __sock_release+0x8b/0x250 net/socket.c:578 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 985 Comm: khungtaskd Not tainted 4.19.0-rc2+ #52 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+0x1c4/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.3+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x1ed 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:144 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0xb3e/0x1050 kernel/hung_task.c:265 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57