============================================ WARNING: possible recursive locking detected 5.18.0-rc5-syzkaller-00178-g30c8e80f7932 #0 Not tainted -------------------------------------------- syz-executor195/3784 is trying to acquire lock: ffff8880185e44d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] ffff8880185e44d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4223 [inline] ffff8880185e44d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __dev_queue_xmit+0x2bd3/0x3920 net/core/dev.c:4172 but task is already holding lock: ffff88802056c4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] ffff88802056c4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4223 [inline] ffff88802056c4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x318/0xbe0 net/sched/sch_generic.c:340 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 9 locks held by syz-executor195/3784: #0: ffffffff8bd7f5e0 (rcu_read_lock){....}-{1:2}, at: l3mdev_l3_out include/net/l3mdev.h:198 [inline] #0: ffffffff8bd7f5e0 (rcu_read_lock){....}-{1:2}, at: l3mdev_ip6_out include/net/l3mdev.h:219 [inline] #0: ffffffff8bd7f5e0 (rcu_read_lock){....}-{1:2}, at: rawv6_send_hdrinc net/ipv6/raw.c:677 [inline] #0: ffffffff8bd7f5e0 (rcu_read_lock){....}-{1:2}, at: rawv6_sendmsg+0x1f57/0x3ab0 net/ipv6/raw.c:944 #1: ffffffff8bd7f580 (rcu_read_lock_bh){....}-{1:2}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:95 [inline] #1: ffffffff8bd7f580 (rcu_read_lock_bh){....}-{1:2}, at: ip6_finish_output2+0x2ad/0x1500 net/ipv6/ip6_output.c:112 #2: ffffffff8bd7f580 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1e3/0x3920 net/core/dev.c:4100 #3: ffff888023fa4258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:359 [inline] #3: ffff888023fa4258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:187 [inline] #3: ffff888023fa4258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:184 [inline] #3: ffff888023fa4258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3746 [inline] #3: ffff888023fa4258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x1293/0x3920 net/core/dev.c:4141 #4: ffff88802056c4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] #4: ffff88802056c4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4223 [inline] #4: ffff88802056c4d8 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x318/0xbe0 net/sched/sch_generic.c:340 #5: ffff8880202160f0 (k-slock-AF_INET6){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:359 [inline] #5: ffff8880202160f0 (k-slock-AF_INET6){+...}-{2:2}, at: icmpv6_xmit_lock net/ipv6/icmp.c:108 [inline] #5: ffff8880202160f0 (k-slock-AF_INET6){+...}-{2:2}, at: icmp6_send+0xd3b/0x2340 net/ipv6/icmp.c:540 #6: ffffffff8bd7f5e0 (rcu_read_lock){....}-{1:2}, at: icmp6_send+0x132f/0x2340 net/ipv6/icmp.c:600 #7: ffffffff8bd7f580 (rcu_read_lock_bh){....}-{1:2}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:95 [inline] #7: ffffffff8bd7f580 (rcu_read_lock_bh){....}-{1:2}, at: ip6_finish_output2+0x2ad/0x1500 net/ipv6/ip6_output.c:112 #8: ffffffff8bd7f580 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1e3/0x3920 net/core/dev.c:4100 stack backtrace: CPU: 2 PID: 3784 Comm: syz-executor195 Not tainted 5.18.0-rc5-syzkaller-00178-g30c8e80f7932 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2958 [inline] check_deadlock kernel/locking/lockdep.c:3001 [inline] validate_chain kernel/locking/lockdep.c:3790 [inline] __lock_acquire.cold+0x12c/0x3a7 kernel/locking/lockdep.c:5029 lock_acquire kernel/locking/lockdep.c:5641 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5606 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:349 [inline] __netif_tx_lock include/linux/netdevice.h:4223 [inline] __dev_queue_xmit+0x2bd3/0x3920 net/core/dev.c:4172 neigh_hh_output include/net/neighbour.h:533 [inline] neigh_output include/net/neighbour.h:547 [inline] ip6_finish_output2+0xf80/0x1500 net/ipv6/ip6_output.c:126 __ip6_finish_output net/ipv6/ip6_output.c:191 [inline] __ip6_finish_output+0x61e/0xe90 net/ipv6/ip6_output.c:170 ip6_finish_output+0x32/0x280 net/ipv6/ip6_output.c:201 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x1e4/0x530 net/ipv6/ip6_output.c:224 dst_output include/net/dst.h:451 [inline] ip6_local_out+0xaf/0x1a0 net/ipv6/output_core.c:161 ip6_send_skb+0xb7/0x340 net/ipv6/ip6_output.c:1925 ip6_push_pending_frames+0xdd/0x100 net/ipv6/ip6_output.c:1945 icmpv6_push_pending_frames+0x294/0x470 net/ipv6/icmp.c:303 icmp6_send+0x1b1d/0x2340 net/ipv6/icmp.c:619 __icmpv6_send include/linux/icmpv6.h:28 [inline] icmpv6_send include/linux/icmpv6.h:49 [inline] ip6_link_failure+0x2d/0x520 net/ipv6/route.c:2786 dst_link_failure include/net/dst.h:430 [inline] ip_tunnel_xmit+0x1648/0x2c00 net/ipv4/ip_tunnel.c:817 erspan_xmit+0x7ec/0x29a0 net/ipv4/ip_gre.c:711 __netdev_start_xmit include/linux/netdevice.h:4775 [inline] netdev_start_xmit include/linux/netdevice.h:4789 [inline] xmit_one net/core/dev.c:3532 [inline] dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3548 sch_direct_xmit+0x19f/0xbe0 net/sched/sch_generic.c:342 __dev_xmit_skb net/core/dev.c:3759 [inline] __dev_queue_xmit+0x14c0/0x3920 net/core/dev.c:4141 neigh_resolve_output net/core/neighbour.c:1528 [inline] neigh_resolve_output+0x50e/0x830 net/core/neighbour.c:1508 neigh_output include/net/neighbour.h:549 [inline] ip6_finish_output2+0x56e/0x1500 net/ipv6/ip6_output.c:126 __ip6_finish_output net/ipv6/ip6_output.c:191 [inline] __ip6_finish_output+0x61e/0xe90 net/ipv6/ip6_output.c:170 ip6_finish_output+0x32/0x280 net/ipv6/ip6_output.c:201 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x1e4/0x530 net/ipv6/ip6_output.c:224 dst_output include/net/dst.h:451 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] rawv6_send_hdrinc net/ipv6/raw.c:687 [inline] rawv6_sendmsg+0x217f/0x3ab0 net/ipv6/raw.c:944 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 sock_write_iter+0x283/0x3c0 net/socket.c:1061 call_write_iter include/linux/fs.h:2050 [inline] new_sync_write+0x38a/0x560 fs/read_write.c:504 vfs_write+0x7c0/0xac0 fs/read_write.c:591 ksys_write+0x1e8/0x250 fs/read_write.c:644 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f223d71fbb9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 15 00 00 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe77663b68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f223d71fbb9 RDX: 0000000000000028 RSI: 0000000020000140 RDI: 0000000000000005 RBP: 0000000000000000 R08: 000000000000000d R09: 000000000000000d R10: 000000000000000d R11: 0000000000000246 R12: 00007ffe77663b80 R13: 00000000000f4240 R14: 000000000000de22 R15: 00007ffe77663b74