------------[ cut here ]------------ WARNING: CPU: 0 PID: 4968 at include/net/sock.h:628 sk_nulls_del_node_init_rcu include/net/sock.h:628 [inline]() WARNING: CPU: 0 PID: 4968 at include/net/sock.h:628 udp_lib_unhash+0x545/0x6a0 net/ipv4/udp.c:1406() Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 4968 Comm: syzkaller742045 Not tainted 4.4.112-g3fc4284 #32 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 803ff35879798751 ffff8800b1b2fa30 ffffffff81d054ed ffffffff83843200 ffff8800b1b2fb08 ffffffff83cf1d40 0000000000000009 0000000000000274 ffff8800b1b2faf8 ffffffff81419dca 0000000041b58ab3 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x124 lib/dump_stack.c:51 [] panic+0x1aa/0x388 kernel/panic.c:112 [] warn_slowpath_common+0x125/0x140 kernel/panic.c:455 [] warn_slowpath_null+0x29/0x30 kernel/panic.c:492 [] sk_nulls_del_node_init_rcu include/net/sock.h:628 [inline] [] udp_lib_unhash+0x545/0x6a0 net/ipv4/udp.c:1406 [] sk_common_release+0xbd/0x300 net/core/sock.c:2690 [] udp_lib_close+0x15/0x20 include/net/udp.h:190 [] inet_release+0xfa/0x1d0 net/ipv4/af_inet.c:435 [] sock_release+0x8d/0x1e0 net/socket.c:586 [] sock_close+0x16/0x20 net/socket.c:1037 [] __fput+0x233/0x6d0 fs/file_table.c:208 [] ____fput+0x15/0x20 fs/file_table.c:244 [] task_work_run+0x104/0x180 kernel/task_work.c:115 [] exit_task_work include/linux/task_work.h:21 [inline] [] do_exit+0x871/0x2a20 kernel/exit.c:755 [] do_group_exit+0x108/0x320 kernel/exit.c:885 [] SYSC_exit_group kernel/exit.c:896 [inline] [] SyS_exit_group+0x1d/0x20 kernel/exit.c:894 [] entry_SYSCALL_64_fastpath+0x16/0x92 Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Rebooting in 86400 seconds..