INFO: task syz-executor.0:20481 blocked for more than 143 seconds. Not tainted 5.1.0+ #10 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28128 20481 8376 0x00000004 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 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:168 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: 0033:0x412f61 Code: 84 3e 02 00 00 48 8b 08 48 8b 54 24 70 48 39 d1 0f 85 41 01 00 00 0f b6 48 17 f6 c1 40 0f 85 99 00 00 00 0f b6 0d 23 ef 39 01 <84> c9 0f 84 80 00 00 00 48 8b 48 20 31 d2 31 db eb 04 48 83 c2 08 RSP: 002b:00007ffd77bfa5b0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000412f61 RDX: 0000000000000000 RSI: 0000000000000081 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffffffffffff R10: 0000000000761888 R11: 0000000000000293 R12: 0000000000761898 R13: 0000000000000001 R14: 0000000000000002 R15: 000000000075c06c Showing all locks held in the system: 1 lock held by khungtaskd/1041: #0: 00000000ad597e46 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5148 2 locks held by rsyslogd/8247: #0: 0000000037e90062 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 #1: 00000000a235bd7e (logbuf_lock){-.-.}, at: __debug_check_no_obj_freed lib/debugobjects.c:776 [inline] #1: 00000000a235bd7e (logbuf_lock){-.-.}, at: debug_check_no_obj_freed+0xbe/0x464 lib/debugobjects.c:817 2 locks held by getty/8337: #0: 00000000af9c20c6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000005a72d8e7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8338: #0: 000000002cb447ae (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000097962dd0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8339: #0: 00000000b3765b43 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000e5e67ca8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8340: #0: 000000001436ffb1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000004cef8f33 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8341: #0: 0000000018bf5a20 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000075e15d07 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8342: #0: 00000000e15e00d2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000015e67bf (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8343: #0: 00000000fcf94986 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000001ae01770 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.0/20481: #0: 000000003d02c89f (&sb->s_type->i_mutex_key#11){+.+.}, at: inode_lock include/linux/fs.h:778 [inline] #0: 000000003d02c89f (&sb->s_type->i_mutex_key#11){+.+.}, at: __sock_release+0x89/0x2a0 net/socket.c:606 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1041 Comm: khungtaskd Not tainted 5.1.0+ #10 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.1.0+ #10 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x50 kernel/kcov.c:95 Code: 89 25 44 5b f5 08 41 bc f4 ff ff ff e8 7d 1b ea ff 48 c7 05 2e 5b f5 08 00 00 00 00 e9 a4 e9 ff ff 90 90 90 90 90 90 90 90 90 <55> 48 89 e5 48 8b 75 08 65 48 8b 04 25 c0 fd 01 00 65 8b 15 10 7a RSP: 0018:ffff8880a98dfd30 EFLAGS: 00000093 RAX: ffff8880ae927618 RBX: 0000000000000001 RCX: ffffffff8164a0da RDX: ffff8880ae927618 RSI: ffff8880ae927608 RDI: 0000000000000001 RBP: ffff8880a98dfd58 R08: ffff8880a98d0340 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880ae927608 R13: 0000000000000000 R14: ffff8880ae927618 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 000000008db17000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __tick_nohz_idle_stop_tick kernel/time/tick-sched.c:941 [inline] tick_nohz_idle_stop_tick+0x5bd/0xc20 kernel/time/tick-sched.c:972 cpuidle_idle_call kernel/sched/idle.c:150 [inline] do_idle+0x36d/0x560 kernel/sched/idle.c:262 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:353 start_secondary+0x34e/0x4c0 arch/x86/kernel/smpboot.c:267 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243