============================================ WARNING: possible recursive locking detected 5.18.0-rc4-syzkaller-00202-g79396934e289 #0 Not tainted -------------------------------------------- syz-executor.2/10800 is trying to acquire lock: ffff88801c390458 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] ffff88801c390458 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4223 [inline] ffff88801c390458 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x318/0xbe0 net/sched/sch_generic.c:340 but task is already holding lock: ffff888022d47cd8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] ffff888022d47cd8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4223 [inline] ffff888022d47cd8 (_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 12 locks held by syz-executor.2/10800: #0: ffffffff8bd820e0 (rcu_read_lock){....}-{1:2}, at: l3mdev_l3_out include/net/l3mdev.h:198 [inline] #0: ffffffff8bd820e0 (rcu_read_lock){....}-{1:2}, at: l3mdev_ip6_out include/net/l3mdev.h:219 [inline] #0: ffffffff8bd820e0 (rcu_read_lock){....}-{1:2}, at: rawv6_send_hdrinc net/ipv6/raw.c:677 [inline] #0: ffffffff8bd820e0 (rcu_read_lock){....}-{1:2}, at: rawv6_sendmsg+0x1f57/0x3ab0 net/ipv6/raw.c:944 #1: ffffffff8bd82080 (rcu_read_lock_bh){....}-{1:2}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:95 [inline] #1: ffffffff8bd82080 (rcu_read_lock_bh){....}-{1:2}, at: ip6_finish_output2+0x2ad/0x1500 net/ipv6/ip6_output.c:112 #2: ffffffff8bd82080 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1e3/0x3920 net/core/dev.c:4100 #3: ffff88807eeb3258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:359 [inline] #3: ffff88807eeb3258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:187 [inline] #3: ffff88807eeb3258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:184 [inline] #3: ffff88807eeb3258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3746 [inline] #3: ffff88807eeb3258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x1293/0x3920 net/core/dev.c:4141 #4: ffff888022d47cd8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] #4: ffff888022d47cd8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4223 [inline] #4: ffff888022d47cd8 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x318/0xbe0 net/sched/sch_generic.c:340 #5: ffff888023b580b0 (k-slock-AF_INET6){+.-.}-{2:2}, at: spin_trylock include/linux/spinlock.h:359 [inline] #5: ffff888023b580b0 (k-slock-AF_INET6){+.-.}-{2:2}, at: icmpv6_xmit_lock net/ipv6/icmp.c:108 [inline] #5: ffff888023b580b0 (k-slock-AF_INET6){+.-.}-{2:2}, at: icmp6_send+0xd3b/0x2340 net/ipv6/icmp.c:540 #6: ffffffff8bd820e0 (rcu_read_lock){....}-{1:2}, at: icmp6_send+0x132f/0x2340 net/ipv6/icmp.c:600 #7: ffffffff8bd82080 (rcu_read_lock_bh){....}-{1:2}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:95 [inline] #7: ffffffff8bd82080 (rcu_read_lock_bh){....}-{1:2}, at: ip6_finish_output2+0x2ad/0x1500 net/ipv6/ip6_output.c:112 #8: ffffffff8bd820e0 (rcu_read_lock){....}-{1:2}, at: ip6_nd_hdr net/ipv6/ndisc.c:466 [inline] #8: ffffffff8bd820e0 (rcu_read_lock){....}-{1:2}, at: ndisc_send_skb+0x844/0x17f0 net/ipv6/ndisc.c:501 #9: ffffffff8bd82080 (rcu_read_lock_bh){....}-{1:2}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:95 [inline] #9: ffffffff8bd82080 (rcu_read_lock_bh){....}-{1:2}, at: ip6_finish_output2+0x2ad/0x1500 net/ipv6/ip6_output.c:112 #10: ffffffff8bd82080 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1e3/0x3920 net/core/dev.c:4100 #11: ffff88805d97b258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:359 [inline] #11: ffff88805d97b258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:187 [inline] #11: ffff88805d97b258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:184 [inline] #11: ffff88805d97b258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3746 [inline] #11: ffff88805d97b258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x1293/0x3920 net/core/dev.c:4141 stack backtrace: CPU: 0 PID: 10800 Comm: syz-executor.2 Not tainted 5.18.0-rc4-syzkaller-00202-g79396934e289 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 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] sch_direct_xmit+0x318/0xbe0 net/sched/sch_generic.c:340 __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] ndisc_send_skb+0xa92/0x17f0 net/ipv6/ndisc.c:507 ndisc_send_ns+0xa6/0x120 net/ipv6/ndisc.c:665 ndisc_solicit+0x2cd/0x4f0 net/ipv6/ndisc.c:757 neigh_probe+0xc2/0x110 net/core/neighbour.c:1040 __neigh_event_send+0xac3/0x15c0 net/core/neighbour.c:1207 neigh_event_send_probe include/net/neighbour.h:473 [inline] neigh_event_send include/net/neighbour.h:479 [inline] neigh_event_send include/net/neighbour.h:477 [inline] neigh_resolve_output+0x53d/0x830 net/core/neighbour.c:1512 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] 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 ____sys_sendmsg+0x32b/0x800 net/socket.c:2413 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467 __sys_sendmmsg+0x195/0x470 net/socket.c:2553 __do_sys_sendmmsg net/socket.c:2582 [inline] __se_sys_sendmmsg net/socket.c:2579 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2579 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: 0033:0x7f6360a890e9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f6361b7d168 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f6360b9bf60 RCX: 00007f6360a890e9 RDX: 0000000000000002 RSI: 0000000020000240 RDI: 0000000000000003 RBP: 00007f6360ae308d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff1fa4ee0f R14: 00007f6361b7d300 R15: 0000000000022000 syz-executor.2 (10800) used greatest stack depth: 21408 bytes left