batman_adv: batadv0: Interface activated: batadv_slave_1 IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready ============================================ WARNING: possible recursive locking detected 4.19.135-syzkaller #0 Not tainted -------------------------------------------- syz-executor916/6447 is trying to acquire lock: 00000000ec7871f0 (_xmit_ETHER#2){+.-.}, at: spin_lock include/linux/spinlock.h:329 [inline] 00000000ec7871f0 (_xmit_ETHER#2){+.-.}, at: __netif_tx_lock include/linux/netdevice.h:3828 [inline] 00000000ec7871f0 (_xmit_ETHER#2){+.-.}, at: __dev_queue_xmit+0x2592/0x2e00 net/core/dev.c:3834 but task is already holding lock: 000000002216d9e3 (_xmit_ETHER#2){+.-.}, at: spin_lock include/linux/spinlock.h:329 [inline] 000000002216d9e3 (_xmit_ETHER#2){+.-.}, at: __netif_tx_lock include/linux/netdevice.h:3828 [inline] 000000002216d9e3 (_xmit_ETHER#2){+.-.}, at: sch_direct_xmit+0x254/0xf50 net/sched/sch_generic.c:330 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(_xmit_ETHER#2); lock(_xmit_ETHER#2); *** DEADLOCK *** May be due to missing lock nesting notation 11 locks held by syz-executor916/6447: #0: 0000000041be4ca5 (rcu_read_lock){....}, at: l3mdev_l3_out include/net/l3mdev.h:172 [inline] #0: 0000000041be4ca5 (rcu_read_lock){....}, at: l3mdev_ip6_out include/net/l3mdev.h:193 [inline] #0: 0000000041be4ca5 (rcu_read_lock){....}, at: rawv6_send_hdrinc net/ipv6/raw.c:682 [inline] #0: 0000000041be4ca5 (rcu_read_lock){....}, at: rawv6_sendmsg+0x1e3d/0x36a0 net/ipv6/raw.c:947 #1: 00000000fac33b54 (rcu_read_lock_bh){....}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline] #1: 00000000fac33b54 (rcu_read_lock_bh){....}, at: ip6_finish_output2+0x1f2/0x2290 net/ipv6/ip6_output.c:106 #2: 00000000fac33b54 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x1e2/0x2e00 net/core/dev.c:3773 #3: 00000000cac4d69a (&(&sch->seqlock)->rlock){+...}, at: spin_trylock include/linux/spinlock.h:339 [inline] #3: 00000000cac4d69a (&(&sch->seqlock)->rlock){+...}, at: qdisc_run_begin include/net/sch_generic.h:130 [inline] #3: 00000000cac4d69a (&(&sch->seqlock)->rlock){+...}, at: qdisc_run include/net/pkt_sched.h:119 [inline] #3: 00000000cac4d69a (&(&sch->seqlock)->rlock){+...}, at: __dev_xmit_skb net/core/dev.c:3451 [inline] #3: 00000000cac4d69a (&(&sch->seqlock)->rlock){+...}, at: __dev_queue_xmit+0x278b/0x2e00 net/core/dev.c:3807 #4: 00000000ce3642cd (dev->qdisc_running_key ?: &qdisc_running_key){+...}, at: neigh_resolve_output+0x55a/0x910 net/core/neighbour.c:1374 #5: 000000002216d9e3 (_xmit_ETHER#2){+.-.}, at: spin_lock include/linux/spinlock.h:329 [inline] #5: 000000002216d9e3 (_xmit_ETHER#2){+.-.}, at: __netif_tx_lock include/linux/netdevice.h:3828 [inline] #5: 000000002216d9e3 (_xmit_ETHER#2){+.-.}, at: sch_direct_xmit+0x254/0xf50 net/sched/sch_generic.c:330 #6: 0000000041be4ca5 (rcu_read_lock){....}, at: icmpv6_send+0x0/0x210 net/ipv6/ip6_icmp.c:31 #7: 0000000094cb44d9 (k-slock-AF_INET6){+...}, at: spin_trylock include/linux/spinlock.h:339 [inline] #7: 0000000094cb44d9 (k-slock-AF_INET6){+...}, at: icmpv6_xmit_lock net/ipv6/icmp.c:119 [inline] #7: 0000000094cb44d9 (k-slock-AF_INET6){+...}, at: icmp6_send+0xfea/0x2230 net/ipv6/icmp.c:532 #8: 0000000041be4ca5 (rcu_read_lock){....}, at: icmp6_send+0x1685/0x2230 net/ipv6/icmp.c:565 #9: 00000000fac33b54 (rcu_read_lock_bh){....}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline] #9: 00000000fac33b54 (rcu_read_lock_bh){....}, at: ip6_finish_output2+0x1f2/0x2290 net/ipv6/ip6_output.c:106 #10: 00000000fac33b54 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x1e2/0x2e00 net/core/dev.c:3773 stack backtrace: CPU: 0 PID: 6447 Comm: syz-executor916 Not tainted 4.19.135-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+0x1fc/0x2fe lib/dump_stack.c:118 print_deadlock_bug kernel/locking/lockdep.c:1763 [inline] check_deadlock kernel/locking/lockdep.c:1807 [inline] validate_chain kernel/locking/lockdep.c:2403 [inline] __lock_acquire.cold+0x121/0x57e kernel/locking/lockdep.c:3415 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3907 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] __netif_tx_lock include/linux/netdevice.h:3828 [inline] __dev_queue_xmit+0x2592/0x2e00 net/core/dev.c:3834 neigh_resolve_output+0x55a/0x910 net/core/neighbour.c:1374 neigh_output include/net/neighbour.h:501 [inline] ip6_finish_output2+0x113d/0x2290 net/ipv6/ip6_output.c:120 ip6_finish_output+0x7eb/0xc10 net/ipv6/ip6_output.c:154 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip6_output+0x205/0x770 net/ipv6/ip6_output.c:171 dst_output include/net/dst.h:455 [inline] ip6_local_out+0xaf/0x170 net/ipv6/output_core.c:178 ip6_send_skb+0xb3/0x300 net/ipv6/ip6_output.c:1699 ip6_push_pending_frames+0xbd/0xe0 net/ipv6/ip6_output.c:1719 icmpv6_push_pending_frames+0x294/0x470 net/ipv6/icmp.c:288 icmp6_send+0x1b5f/0x2230 net/ipv6/icmp.c:584 icmpv6_send+0xde/0x210 net/ipv6/ip6_icmp.c:43 ip6_link_failure+0x26/0x4e0 net/ipv6/route.c:2297 dst_link_failure include/net/dst.h:438 [inline] ip_tunnel_xmit+0x195f/0x37f0 net/ipv4/ip_tunnel.c:789 erspan_xmit+0x1837/0x2790 net/ipv4/ip_gre.c:756 __netdev_start_xmit include/linux/netdevice.h:4333 [inline] netdev_start_xmit include/linux/netdevice.h:4347 [inline] xmit_one net/core/dev.c:3256 [inline] dev_hard_start_xmit+0x1a8/0x920 net/core/dev.c:3272 sch_direct_xmit+0x2d6/0xf50 net/sched/sch_generic.c:332 qdisc_restart net/sched/sch_generic.c:395 [inline] __qdisc_run+0x4d0/0x1630 net/sched/sch_generic.c:403 qdisc_run include/net/pkt_sched.h:120 [inline] __dev_xmit_skb net/core/dev.c:3451 [inline] __dev_queue_xmit+0x2102/0x2e00 net/core/dev.c:3807 neigh_resolve_output+0x55a/0x910 net/core/neighbour.c:1374 neigh_output include/net/neighbour.h:501 [inline] ip6_finish_output2+0x113d/0x2290 net/ipv6/ip6_output.c:120 ip6_finish_output+0x7eb/0xc10 net/ipv6/ip6_output.c:154 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip6_output+0x205/0x770 net/ipv6/ip6_output.c:171 dst_output include/net/dst.h:455 [inline] NF_HOOK include/linux/netfilter.h:289 [inline] rawv6_send_hdrinc net/ipv6/raw.c:692 [inline] rawv6_sendmsg+0x202c/0x36a0 net/ipv6/raw.c:947 inet_sendmsg+0x132/0x5a0 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xc3/0x120 net/socket.c:632 sock_write_iter+0x287/0x3c0 net/socket.c:901 call_write_iter include/linux/fs.h:1821 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x51b/0x770 fs/read_write.c:487 vfs_write+0x1f3/0x540 fs/read_write.c:549 ksys_write+0x12b/0x2a0 fs/read_write.c:599 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x449ee9 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 2b 0e fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fffc4bee918 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000449ee9 RDX: 0000000000000028 RSI: 0000000020000140 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffc4bee990 R13: 0000000000000003 R14: 0000000000959914 R15: 0000000000000013