netlink: 244 bytes leftover after parsing attributes in process `syz-executor366'. ============================================ WARNING: possible recursive locking detected 5.18.0-rc2-syzkaller-00275-g59250f8a7f3a #0 Not tainted -------------------------------------------- syz-executor366/3617 is trying to acquire lock: ffff888076f24218 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] ffff888076f24218 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3789 [inline] ffff888076f24218 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x2f59/0x39c0 net/core/dev.c:4141 but task is already holding lock: ffff88807769d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:359 [inline] ffff88807769d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:187 [inline] ffff88807769d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:184 [inline] ffff88807769d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3746 [inline] ffff88807769d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x130e/0x39c0 net/core/dev.c:4141 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(dev->qdisc_tx_busylock ?: &qdisc_tx_busylock); lock(dev->qdisc_tx_busylock ?: &qdisc_tx_busylock); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by syz-executor366/3617: #0: ffffffff8bd81d80 (rcu_read_lock_bh){....}-{1:2}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:95 [inline] #0: ffffffff8bd81d80 (rcu_read_lock_bh){....}-{1:2}, at: ip_finish_output2+0x292/0x2170 net/ipv4/ip_output.c:214 #1: ffffffff8bd81d80 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1e3/0x39c0 net/core/dev.c:4100 #2: ffff88807769d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:359 [inline] #2: ffff88807769d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:187 [inline] #2: ffff88807769d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:184 [inline] #2: ffff88807769d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3746 [inline] #2: ffff88807769d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x130e/0x39c0 net/core/dev.c:4141 #3: ffffffff8bd81d80 (rcu_read_lock_bh){....}-{1:2}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:95 [inline] #3: ffffffff8bd81d80 (rcu_read_lock_bh){....}-{1:2}, at: ip_finish_output2+0x292/0x2170 net/ipv4/ip_output.c:214 #4: ffffffff8bd81d80 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1e3/0x39c0 net/core/dev.c:4100 stack backtrace: CPU: 1 PID: 3617 Comm: syz-executor366 Not tainted 5.18.0-rc2-syzkaller-00275-g59250f8a7f3a #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] __dev_xmit_skb net/core/dev.c:3789 [inline] __dev_queue_xmit+0x2f59/0x39c0 net/core/dev.c:4141 neigh_hh_output include/net/neighbour.h:533 [inline] neigh_output include/net/neighbour.h:547 [inline] ip_finish_output2+0x14df/0x2170 net/ipv4/ip_output.c:228 __ip_finish_output net/ipv4/ip_output.c:306 [inline] __ip_finish_output+0x396/0x650 net/ipv4/ip_output.c:288 ip_finish_output+0x32/0x280 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip_output+0x196/0x310 net/ipv4/ip_output.c:430 dst_output include/net/dst.h:451 [inline] ip_local_out+0xaf/0x1a0 net/ipv4/ip_output.c:126 iptunnel_xmit+0x68c/0xa50 net/ipv4/ip_tunnel_core.c:82 ip_tunnel_xmit+0x10a8/0x2b70 net/ipv4/ip_tunnel.c:810 gre_tap_xmit+0x504/0x630 net/ipv4/ip_gre.c:741 __netdev_start_xmit include/linux/netdevice.h:4778 [inline] netdev_start_xmit include/linux/netdevice.h:4792 [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+0x153b/0x39c0 net/core/dev.c:4141 neigh_hh_output include/net/neighbour.h:533 [inline] neigh_output include/net/neighbour.h:547 [inline] ip_finish_output2+0x14df/0x2170 net/ipv4/ip_output.c:228 __ip_finish_output net/ipv4/ip_output.c:306 [inline] __ip_finish_output+0x396/0x650 net/ipv4/ip_output.c:288 ip_finish_output+0x32/0x280 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip_output+0x196/0x310 net/ipv4/ip_output.c:430 dst_output include/net/dst.h:451 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] ip_send_skb+0xd4/0x260 net/ipv4/ip_output.c:1571 udp_send_skb+0x6d2/0x11b0 net/ipv4/udp.c:967 udp_sendmsg+0x1bae/0x2730 net/ipv4/udp.c:1254 udpv6_sendmsg+0x1747/0x2c30 net/ipv6/udp.c:1364 inet6_sendmsg+0x99/0xe0 net/ipv6/af_inet6.c:652 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: 0033:0x7f96101719f9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 a1 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f961011f308 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f96101fa4e8 RCX: 00007f96101719f9 RDX: 0000000000026700 RSI: 00000000200092c0 RDI: 0000000000000005 RBP: 00007f96101fa4e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f96101fa4ec R13: 00007f96101c74a4 R14: 6d32cc5e8ead0600 R15: 0000000000022000