NOHZ: local_softirq_pending 08 INFO: task syz-executor.4:17229 blocked for more than 140 seconds. Not tainted 4.19.121-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28416 17229 6835 0x00000004 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3559 exp_funnel_lock kernel/rcu/tree_exp.h:320 [inline] _synchronize_rcu_expedited+0x64f/0x750 kernel/rcu/tree_exp.h:667 synchronize_net+0x37/0x50 net/core/dev.c:9252 packet_set_ring+0x22d/0x1aa0 net/packet/af_packet.c:4387 packet_release+0x564/0xc70 net/packet/af_packet.c:3046 __sock_release+0xcd/0x2a0 net/socket.c:579 sock_close+0x15/0x20 net/socket.c:1140 __fput+0x2cd/0x890 fs/file_table.c:278 task_work_run+0x13f/0x1b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x25a/0x2b0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x416421 Code: Bad RIP value. RSP: 002b:00007ffd5f20d5e0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000006 RCX: 0000000000416421 RDX: 0000000000000000 RSI: ffffffff874009b5 RDI: 0000000000000005 RBP: 0000000000000001 R08: ffffffff81009d54 R09: 0000000085907a85 R10: 00007ffd5f20d6d0 R11: 0000000000000293 R12: 000000000078c900 R13: 000000000078c900 R14: ffffffffffffffff R15: 000000000078bfac Showing all locks held in the system: 1 lock held by khungtaskd/1079: #0: 00000000d30ac857 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4440 1 lock held by in:imklog/6134: #0: 00000000c3c6baa6 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:767 2 locks held by agetty/6360: #0: 000000000ffddfa8 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 00000000917c0d36 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1a50 drivers/tty/n_tty.c:2154 2 locks held by syz-executor.4/17229: #0: 00000000c6d2bcec (&sb->s_type->i_mutex_key#13){+.+.}, at: inode_lock include/linux/fs.h:748 [inline] #0: 00000000c6d2bcec (&sb->s_type->i_mutex_key#13){+.+.}, at: __sock_release+0x86/0x2a0 net/socket.c:578 #1: 000000002314300c (sk_lock-AF_PACKET){+.+.}, at: lock_sock include/net/sock.h:1506 [inline] #1: 000000002314300c (sk_lock-AF_PACKET){+.+.}, at: packet_release+0x50b/0xc70 net/packet/af_packet.c:3043 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1079 Comm: khungtaskd Not tainted 4.19.121-syzkaller #0 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+0x188/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1eb lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x962/0xe40 kernel/hung_task.c:287 kthread+0x34a/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3673 Comm: systemd-journal Not tainted 4.19.121-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_acquire+0x7a2/0x49c0 kernel/locking/lockdep.c:3405 Code: 45 31 ff 45 85 c9 41 0f 94 c7 48 b8 00 00 00 00 00 fc ff df 4c 89 d2 48 c1 ea 03 80 3c 02 00 0f 85 78 2d 00 00 48 8b 54 24 78 <4d> 89 22 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 0f b6 04 02 84 RSP: 0018:ffff888094ff7bb0 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: 000000000000002d RCX: 1ffff110129fddb5 RDX: ffff888094feed80 RSI: ffff888094feed88 RDI: ffffffff8b3ff1b0 RBP: ffff888094ff7d80 R08: 0000000000000000 R09: 0000000000000000 R10: ffff888094feed88 R11: 000000000000002d R12: 0000000000000000 R13: 000000000002002d R14: ffff888094fee500 R15: 0000000000000001 FS: 00007f888d9c08c0(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f888ae19000 CR3: 0000000094d05000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x170/0x400 kernel/locking/lockdep.c:3907 rcu_lock_acquire include/linux/rcupdate.h:242 [inline] rcu_read_lock include/linux/rcupdate.h:627 [inline] mntput_no_expire+0x40/0x910 fs/namespace.c:1121 mntput+0x67/0x90 fs/namespace.c:1187 do_faccessat+0x48a/0x7a0 fs/open.c:431 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f888cc7c9c7 Code: 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d c8 d4 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d4 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffcae073bf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffcae076c20 RCX: 00007f888cc7c9c7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000558fe4bba9a3 RBP: 00007ffcae073d40 R08: 0000558fe4bb03e5 R09: 0000000000000018 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000558fe4ca58c0 R15: 00007ffcae074230