IPv6: ADDRCONF(NETDEV_UP): vxcan1: link is not ready 8021q: adding VLAN 0 to HW filter on device batadv0 netlink: 80 bytes leftover after parsing attributes in process `syz-executor151'. netlink: 48 bytes leftover after parsing attributes in process `syz-executor151'. ============================= WARNING: suspicious RCU usage 4.19.75 #0 Not tainted ----------------------------- include/net/sch_generic.h:419 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 3 locks held by syz-executor151/7601: #0: 00000000c3202c35 (rcu_read_lock_bh){....}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline] #0: 00000000c3202c35 (rcu_read_lock_bh){....}, at: ip_finish_output2+0x2b0/0x1730 net/ipv4/ip_output.c:213 #1: 00000000c3202c35 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x214/0x2fe0 net/core/dev.c:3777 #2: 000000003b4632a0 (&qdisc_tx_lock){+...}, at: spin_lock include/linux/spinlock.h:329 [inline] #2: 000000003b4632a0 (&qdisc_tx_lock){+...}, at: __dev_xmit_skb net/core/dev.c:3470 [inline] #2: 000000003b4632a0 (&qdisc_tx_lock){+...}, at: __dev_queue_xmit+0x147c/0x2fe0 net/core/dev.c:3811 stack backtrace: CPU: 1 PID: 7601 Comm: syz-executor151 Not tainted 4.19.75 #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+0x172/0x1f0 lib/dump_stack.c:113 lockdep_rcu_suspicious+0x153/0x15d kernel/locking/lockdep.c:4536 qdisc_root include/net/sch_generic.h:419 [inline] netem_enqueue+0x1ada/0x28f0 net/sched/sch_netem.c:477 __dev_xmit_skb net/core/dev.c:3495 [inline] __dev_queue_xmit+0x153d/0x2fe0 net/core/dev.c:3811 dev_queue_xmit+0x18/0x20 net/core/dev.c:3876 neigh_hh_output include/net/neighbour.h:491 [inline] neigh_output include/net/neighbour.h:499 [inline] ip_finish_output2+0x1041/0x1730 net/ipv4/ip_output.c:229 ip_finish_output+0x737/0xce0 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip_mc_output+0x298/0xf50 net/ipv4/ip_output.c:390 dst_output include/net/dst.h:447 [inline] ip_local_out+0xbb/0x190 net/ipv4/ip_output.c:124 ip_send_skb+0x42/0xf0 net/ipv4/ip_output.c:1442 udp_send_skb.isra.0+0x6bb/0x11d0 net/ipv4/udp.c:842 udp_sendmsg+0x1e04/0x25e0 net/ipv4/udp.c:1129 inet_sendmsg+0x141/0x5d0 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:632 ___sys_sendmsg+0x3e2/0x920 net/socket.c:2115 __sys_sendmmsg+0x1bf/0x4e0 net/socket.c:2210 __do_sys_sendmmsg net/socket.c:2239 [inline] __se_sys_sendmmsg net/socket.c:2236 [inline] __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2236 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x442259 Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 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 7b 10 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffc62c080b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000442259 RDX: 04000000000001a8 RSI: 0000000020007fc0 RDI: 0000000000000005 RBP: 00007ffc62c080e0 R08: 0000000000000400 R09: 0000000000000400 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000004037f0 R14: 0000000000000000 R15: 0000000000000000