bpfilter: read fail -512 ============================= WARNING: suspicious RCU usage 4.19.0-rc5+ #30 Not tainted ----------------------------- kernel/pid.c:330 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by syz-executor4/29052: #0: 00000000b553d38f (bpfilter_lock){+.+.}, at: __bpfilter_process_sockopt+0x1d0/0x387 net/bpfilter/bpfilter_kern.c:64 stack backtrace: CPU: 1 PID: 29052 Comm: syz-executor4 Not tainted 4.19.0-rc5+ #30 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 lockdep_rcu_suspicious+0x14a/0x153 kernel/locking/lockdep.c:4536 pid_task+0x1ce/0x200 kernel/pid.c:329 shutdown_umh.constprop.0+0x33/0x7c net/bpfilter/bpfilter_kern.c:26 __stop_umh net/bpfilter/bpfilter_kern.c:38 [inline] __bpfilter_process_sockopt.cold.1+0x9b/0xa0 net/bpfilter/bpfilter_kern.c:78 bpfilter_mbox_request+0x4d/0xb0 net/ipv4/bpfilter/sockopt.c:25 bpfilter_ip_set_sockopt+0x33/0x40 net/ipv4/bpfilter/sockopt.c:31 ip_setsockopt+0x125/0x140 net/ipv4/ip_sockglue.c:1253 udp_setsockopt+0x62/0xa0 net/ipv4/udp.c:2501 ipv6_setsockopt+0x149/0x170 net/ipv6/ipv6_sockglue.c:928 tcp_setsockopt+0x93/0xe0 net/ipv4/tcp.c:3062 sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:3038 __sys_setsockopt+0x1ba/0x3c0 net/socket.c:1902 __do_sys_setsockopt net/socket.c:1913 [inline] __se_sys_setsockopt net/socket.c:1910 [inline] __x64_sys_setsockopt+0xbe/0x150 net/socket.c:1910 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457679 Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fcfc82f9c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007fcfc82fa6d4 RCX: 0000000000457679 RDX: 0000000100000040 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000020000040 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d64a8 R14: 00000000004c402c R15: 0000000000000000