device lo entered promiscuous mode netlink: 57 bytes leftover after parsing attributes in process `syz-executor1'. device lo left promiscuous mode ============================= WARNING: suspicious RCU usage 4.17.0-rc1+ #16 Not tainted device lo entered promiscuous mode ----------------------------- net/ipv6/route.c:1550 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 3 locks held by syz-executor2/5049: #0: 00000000f1ba7346 (rcu_read_lock_bh){....}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline] #0: 00000000f1ba7346 (rcu_read_lock_bh){....}, at: ip6_finish_output2+0x253/0x2800 net/ipv6/ip6_output.c:106 #1: 00000000f1ba7346 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x30f/0x34c0 net/core/dev.c:3519 #2: 000000006d0bab6d (rcu_read_lock){....}, at: ip6_link_failure+0xfe/0x790 net/ipv6/route.c:2227 stack backtrace: CPU: 1 PID: 5049 Comm: syz-executor2 Not tainted 4.17.0-rc1+ #16 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+0x1b9/0x294 lib/dump_stack.c:113 lockdep_rcu_suspicious+0x14a/0x153 kernel/locking/lockdep.c:4592 rt6_remove_exception_rt+0x416/0x4d0 net/ipv6/route.c:1549 ip6_link_failure+0x484/0x790 net/ipv6/route.c:2231 dst_link_failure include/net/dst.h:427 [inline] ip6_tnl_xmit+0x49a/0x34b0 net/ipv6/ip6_tunnel.c:1222 ip6ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1374 [inline] ip6_tnl_start_xmit+0x8fc/0x2290 net/ipv6/ip6_tunnel.c:1397 __netdev_start_xmit include/linux/netdevice.h:4087 [inline] netdev_start_xmit include/linux/netdevice.h:4096 [inline] xmit_one net/core/dev.c:3054 [inline] dev_hard_start_xmit+0x264/0xc10 net/core/dev.c:3070 __dev_queue_xmit+0x2724/0x34c0 net/core/dev.c:3585 dev_queue_xmit+0x17/0x20 net/core/dev.c:3618 neigh_direct_output+0x15/0x20 net/core/neighbour.c:1398 neigh_output include/net/neighbour.h:482 [inline] ip6_finish_output2+0xc93/0x2800 net/ipv6/ip6_output.c:120 ip6_finish_output+0x5fe/0xbc0 net/ipv6/ip6_output.c:154 NF_HOOK_COND include/linux/netfilter.h:277 [inline] ip6_output+0x227/0x9b0 net/ipv6/ip6_output.c:171 dst_output include/net/dst.h:444 [inline] NF_HOOK include/linux/netfilter.h:288 [inline] rawv6_send_hdrinc net/ipv6/raw.c:678 [inline] rawv6_sendmsg+0x2674/0x4590 net/ipv6/raw.c:924 inet_sendmsg+0x19f/0x690 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:629 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:639 ___sys_sendmsg+0x805/0x940 net/socket.c:2117 __sys_sendmsg+0x115/0x270 net/socket.c:2155 __do_sys_sendmsg net/socket.c:2164 [inline] __se_sys_sendmsg net/socket.c:2162 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2162 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455389 RSP: 002b:00007f671b331c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f671b3326d4 RCX: 0000000000455389 RDX: 000000000000ff00 RSI: 00000000200000c0 RDI: 0000000000000013 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000004d5 R14: 00000000006fa498 R15: 0000000000000000 device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode net_ratelimit: 18 callbacks suppressed IPv4: Oversized IP packet from 127.0.0.1 IPv4: Oversized IP packet from 127.0.0.1 device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode IPv4: Oversized IP packet from 127.0.0.1 IPv4: Oversized IP packet from 127.0.0.1 device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode IPv4: Oversized IP packet from 127.0.0.1 IPv4: Oversized IP packet from 127.0.0.1 device lo left promiscuous mode device lo entered promiscuous mode IPv4: Oversized IP packet from 127.0.0.1 device lo left promiscuous mode IPv4: Oversized IP packet from 127.0.0.1 device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode IPv4: Oversized IP packet from 127.0.0.1 IPv4: Oversized IP packet from 127.0.0.1 device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode net_ratelimit: 18 callbacks suppressed IPv4: Oversized IP packet from 127.0.0.1 IPv4: Oversized IP packet from 127.0.0.1 device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode IPv4: Oversized IP packet from 127.0.0.1 IPv4: Oversized IP packet from 127.0.0.1 device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode IPv4: Oversized IP packet from 127.0.0.1 IPv4: Oversized IP packet from 127.0.0.1 device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode IPv4: Oversized IP packet from 127.0.0.1 IPv4: Oversized IP packet from 127.0.0.1 device lo entered promiscuous mode IPv4: Oversized IP packet from 127.0.0.1 IPv4: Oversized IP packet from 127.0.0.1 device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode