netlink: 244 bytes leftover after parsing attributes in process `syz-executor122'. ============================================ WARNING: possible recursive locking detected 5.19.0-syzkaller-02972-g200e340f2196 #0 Not tainted -------------------------------------------- syz-executor122/3628 is trying to acquire lock: ffff8880783b5218 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] ffff8880783b5218 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3847 [inline] ffff8880783b5218 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x224b/0x38d0 net/core/dev.c:4221 but task is already holding lock: ffff88801db1d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:359 [inline] ffff88801db1d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:187 [inline] ffff88801db1d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3804 [inline] ffff88801db1d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x13e7/0x38d0 net/core/dev.c:4221 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-executor122/3628: #0: ffffffff8cb1eec0 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:280 #1: ffffffff8cb1eec0 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:280 #2: ffff88801db1d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:359 [inline] #2: ffff88801db1d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:187 [inline] #2: ffff88801db1d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3804 [inline] #2: ffff88801db1d258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x13e7/0x38d0 net/core/dev.c:4221 #3: ffffffff8cb1eec0 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:280 #4: ffffffff8cb1eec0 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:280 stack backtrace: CPU: 1 PID: 3628 Comm: syz-executor122 Not tainted 5.19.0-syzkaller-02972-g200e340f2196 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2988 [inline] check_deadlock kernel/locking/lockdep.c:3031 [inline] validate_chain+0x485d/0x65c0 kernel/locking/lockdep.c:3816 __lock_acquire+0x129a/0x1f80 kernel/locking/lockdep.c:5053 lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5666 __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:3847 [inline] __dev_queue_xmit+0x224b/0x38d0 net/core/dev.c:4221 dev_queue_xmit include/linux/netdevice.h:2994 [inline] neigh_hh_output include/net/neighbour.h:533 [inline] neigh_output include/net/neighbour.h:547 [inline] ip_finish_output2+0xcae/0x11c0 net/ipv4/ip_output.c:228 iptunnel_xmit+0x4cb/0x8d0 net/ipv4/ip_tunnel_core.c:82 ip_tunnel_xmit+0x1c3c/0x24e0 net/ipv4/ip_tunnel.c:811 __gre_xmit net/ipv4/ip_gre.c:469 [inline] gre_tap_xmit+0x4f1/0x6e0 net/ipv4/ip_gre.c:743 __netdev_start_xmit include/linux/netdevice.h:4805 [inline] netdev_start_xmit include/linux/netdevice.h:4819 [inline] xmit_one net/core/dev.c:3590 [inline] dev_hard_start_xmit+0x1af/0x3e0 net/core/dev.c:3606 sch_direct_xmit+0x2ae/0x5e0 net/sched/sch_generic.c:342 __dev_xmit_skb net/core/dev.c:3817 [inline] __dev_queue_xmit+0x19b8/0x38d0 net/core/dev.c:4221 dev_queue_xmit include/linux/netdevice.h:2994 [inline] neigh_hh_output include/net/neighbour.h:533 [inline] neigh_output include/net/neighbour.h:547 [inline] ip_finish_output2+0xcae/0x11c0 net/ipv4/ip_output.c:228 dst_output include/net/dst.h:451 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] ip_send_skb+0x113/0x1a0 net/ipv4/ip_output.c:1593 udp_send_skb+0xa69/0x13f0 net/ipv4/udp.c:967 udp_sendmsg+0x1d30/0x2b00 net/ipv4/udp.c:1254 udpv6_sendmsg+0xc4e/0x3140 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline] ____sys_sendmsg+0x597/0x8e0 net/socket.c:2485 ___sys_sendmsg net/socket.c:2539 [inline] __sys_sendmmsg+0x3d7/0x770 net/socket.c:2625 __do_sys_sendmmsg net/socket.c:2654 [inline] __se_sys_sendmmsg net/socket.c:2651 [inline] __x64_sys_sendmmsg+0x9c/0xb0 net/socket.c:2651 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f7ba462ada9 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:00007ffdacdc0008 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007ffdacdc0030 RCX: 00007f7ba462ada9 RDX: 0000000000026700 RSI: 00000000200092c0 RDI: 0000000000000005 RBP: 0000000000000000 R08: 000000000000000d R09: 000000000000000d R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdacdc0020 R13: 00000000000f4240 R14: 000000000000c359 R15: 00007ffdacdc0014 IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready chnl_net:chnl_net_open(): err: Unable to register and open device, Err:-19 caif:caif_disconnect_client(): nothing to disconnect chnl_net:chnl_flowctrl_cb(): NET flowctrl func called flow: CLOSE/DEINIT chnl_net:chnl_net_open(): state disconnected A link change request failed with some changes committed already. Interface caif0 may have been left with an inconsistent configuration, please check.