============================================ WARNING: possible recursive locking detected 5.17.0-rc4-syzkaller-01454-g6a47cdc38143 #0 Not tainted -------------------------------------------- kworker/1:9/28827 is trying to acquire lock: ffff88801c8a8298 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] ffff88801c8a8298 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4161 [inline] ffff88801c8a8298 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x318/0xbe0 net/sched/sch_generic.c:340 but task is already holding lock: ffff888012d94cd8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] ffff888012d94cd8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4161 [inline] ffff888012d94cd8 (_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 11 locks held by kworker/1:9/28827: #0: ffff888022d0c138 ((wq_completion)mld){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888022d0c138 ((wq_completion)mld){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888022d0c138 ((wq_completion)mld){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff888022d0c138 ((wq_completion)mld){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:631 [inline] #0: ffff888022d0c138 ((wq_completion)mld){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:658 [inline] #0: ffff888022d0c138 ((wq_completion)mld){+.+.}-{0:0}, at: process_one_work+0x890/0x1650 kernel/workqueue.c:2278 #1: ffffc9000dc67db8 ((work_completion)(&(&idev->mc_ifc_work)->work)){+.+.}-{0:0}, at: process_one_work+0x8c4/0x1650 kernel/workqueue.c:2282 #2: ffff88804a9c7538 (&idev->mc_lock){+.+.}-{3:3}, at: mld_ifc_work+0x3d/0xdc0 net/ipv6/mcast.c:2658 #3: ffffffff8bb84360 (rcu_read_lock){....}-{1:2}, at: read_pnet include/net/net_namespace.h:361 [inline] #3: ffffffff8bb84360 (rcu_read_lock){....}-{1:2}, at: dev_net include/linux/netdevice.h:2451 [inline] #3: ffffffff8bb84360 (rcu_read_lock){....}-{1:2}, at: mld_sendpack+0x15c/0xe40 net/ipv6/mcast.c:1793 #4: ffffffff8bb84300 (rcu_read_lock_bh){....}-{1:2}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:95 [inline] #4: ffffffff8bb84300 (rcu_read_lock_bh){....}-{1:2}, at: ip6_finish_output2+0x2ad/0x14f0 net/ipv6/ip6_output.c:112 #5: ffffffff8bb84300 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1e3/0x3660 net/core/dev.c:4060 #6: ffff8880508f0258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:359 [inline] #6: ffff8880508f0258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:187 [inline] #6: ffff8880508f0258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:184 [inline] #6: ffff8880508f0258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3707 [inline] #6: ffff8880508f0258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x1262/0x3660 net/core/dev.c:4101 #7: ffff888012d94cd8 (_xmit_ETHER#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] #7: ffff888012d94cd8 (_xmit_ETHER#2){+.-.}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4161 [inline] #7: ffff888012d94cd8 (_xmit_ETHER#2){+.-.}-{2:2}, at: sch_direct_xmit+0x318/0xbe0 net/sched/sch_generic.c:340 #8: ffffffff8bb84300 (rcu_read_lock_bh){....}-{1:2}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:95 [inline] #8: ffffffff8bb84300 (rcu_read_lock_bh){....}-{1:2}, at: ip_finish_output2+0x292/0x2170 net/ipv4/ip_output.c:214 #9: ffffffff8bb84300 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1e3/0x3660 net/core/dev.c:4060 #10: ffff88801d17f258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: spin_trylock include/linux/spinlock.h:359 [inline] #10: ffff88801d17f258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:187 [inline] #10: ffff88801d17f258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: qdisc_run_begin include/net/sch_generic.h:184 [inline] #10: ffff88801d17f258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_xmit_skb net/core/dev.c:3707 [inline] #10: ffff88801d17f258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock){+...}-{2:2}, at: __dev_queue_xmit+0x1262/0x3660 net/core/dev.c:4101 stack backtrace: CPU: 1 PID: 28827 Comm: kworker/1:9 Not tainted 5.17.0-rc4-syzkaller-01454-g6a47cdc38143 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: mld mld_ifc_work 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:2956 [inline] check_deadlock kernel/locking/lockdep.c:2999 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire.cold+0x213/0x3a9 kernel/locking/lockdep.c:5027 lock_acquire kernel/locking/lockdep.c:5639 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604 __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:4161 [inline] sch_direct_xmit+0x318/0xbe0 net/sched/sch_generic.c:340 __dev_xmit_skb net/core/dev.c:3720 [inline] __dev_queue_xmit+0x148f/0x3660 net/core/dev.c:4101 neigh_hh_output include/net/neighbour.h:533 [inline] neigh_output include/net/neighbour.h:547 [inline] ip_finish_output2+0x14dc/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+0x10aa/0x2b70 net/ipv4/ip_tunnel.c:810 gre_tap_xmit+0x501/0x630 net/ipv4/ip_gre.c:741 __netdev_start_xmit include/linux/netdevice.h:4721 [inline] netdev_start_xmit include/linux/netdevice.h:4735 [inline] xmit_one net/core/dev.c:3493 [inline] dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3509 sch_direct_xmit+0x19f/0xbe0 net/sched/sch_generic.c:342 __dev_xmit_skb net/core/dev.c:3720 [inline] __dev_queue_xmit+0x148f/0x3660 net/core/dev.c:4101 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/0x14f0 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] NF_HOOK include/linux/netfilter.h:301 [inline] mld_sendpack+0x9a3/0xe40 net/ipv6/mcast.c:1826 mld_send_cr net/ipv6/mcast.c:2127 [inline] mld_ifc_work+0x71c/0xdc0 net/ipv6/mcast.c:2659 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295