============================================ WARNING: possible recursive locking detected 5.15.0-syzkaller #0 Not tainted -------------------------------------------- syz-executor.1/17150 is trying to acquire lock: ffff888147854398 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline] ffff888147854398 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4406 [inline] ffff888147854398 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1a1/0x5b0 net/sched/sch_generic.c:340 but task is already holding lock: ffff88801957d098 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline] ffff88801957d098 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4406 [inline] ffff88801957d098 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1a1/0x5b0 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 7 locks held by syz-executor.1/17150: #0: ffffffff8cb1d960 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:268 #1: ffffffff8cb1d960 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:268 #2: ffff888085f1f258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:360 [inline] #2: ffff888085f1f258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:187 [inline] #2: ffff888085f1f258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3804 [inline] #2: ffff888085f1f258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x12f0/0x35c0 net/core/dev.c:4194 #3: ffff88801957d098 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline] #3: ffff88801957d098 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4406 [inline] #3: ffff88801957d098 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x1a1/0x5b0 net/sched/sch_generic.c:340 #4: ffffffff8cb1d960 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:268 #5: ffffffff8cb1d960 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:268 #6: ffff8880828b0258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:360 [inline] #6: ffff8880828b0258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:187 [inline] #6: ffff8880828b0258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3804 [inline] #6: ffff8880828b0258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x12f0/0x35c0 net/core/dev.c:4194 stack backtrace: CPU: 1 PID: 17150 Comm: syz-executor.1 Not tainted 5.15.0-syzkaller #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+0x1dc/0x2d8 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2959 [inline] check_deadlock kernel/locking/lockdep.c:3002 [inline] validate_chain+0x5984/0x8240 kernel/locking/lockdep.c:3791 __lock_acquire+0x1382/0x2b00 kernel/locking/lockdep.c:5030 lock_acquire+0x19f/0x4d0 kernel/locking/lockdep.c:5640 __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:350 [inline] __netif_tx_lock include/linux/netdevice.h:4406 [inline] sch_direct_xmit+0x1a1/0x5b0 net/sched/sch_generic.c:340 __dev_xmit_skb net/core/dev.c:3817 [inline] __dev_queue_xmit+0x196d/0x35c0 net/core/dev.c:4194 neigh_output include/net/neighbour.h:527 [inline] ip_finish_output2+0xd25/0x1990 net/ipv4/ip_output.c:221 iptunnel_xmit+0x4d8/0x8c0 net/ipv4/ip_tunnel_core.c:82 ip_tunnel_xmit+0x1672/0x2740 net/ipv4/ip_tunnel.c:810 __gre_xmit net/ipv4/ip_gre.c:471 [inline] erspan_xmit+0x11f3/0x29a0 net/ipv4/ip_gre.c:712 __netdev_start_xmit include/linux/netdevice.h:4987 [inline] netdev_start_xmit include/linux/netdevice.h:5001 [inline] xmit_one net/core/dev.c:3590 [inline] dev_hard_start_xmit+0x20b/0x450 net/core/dev.c:3606 sch_direct_xmit+0x292/0x5b0 net/sched/sch_generic.c:342 __dev_xmit_skb net/core/dev.c:3817 [inline] __dev_queue_xmit+0x196d/0x35c0 net/core/dev.c:4194 neigh_output include/net/neighbour.h:527 [inline] ip_finish_output2+0xd25/0x1990 net/ipv4/ip_output.c:221 dst_output include/net/dst.h:450 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] ip_send_skb+0x113/0x1a0 net/ipv4/ip_output.c:1555 udp_send_skb+0x97e/0x1240 net/ipv4/udp.c:966 udp_sendmsg+0x23c1/0x34f0 net/ipv4/udp.c:1253 udpv6_sendmsg+0xaf3/0x3760 net/ipv6/udp.c:1360 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg net/socket.c:724 [inline] ____sys_sendmsg+0x5b9/0x910 net/socket.c:2409 ___sys_sendmsg net/socket.c:2463 [inline] __sys_sendmmsg+0x3ba/0x750 net/socket.c:2549 __do_sys_sendmmsg net/socket.c:2578 [inline] __se_sys_sendmmsg net/socket.c:2575 [inline] __x64_sys_sendmmsg+0x9c/0xb0 net/socket.c:2575 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f5082ba1ae9 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5080117188 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f5082cb4f60 RCX: 00007f5082ba1ae9 RDX: 0400000000000132 RSI: 0000000020004d80 RDI: 0000000000000007 RBP: 00007f5082bfbf25 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000004000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff18cebb3f R14: 00007f5080117300 R15: 0000000000022000