============================================ WARNING: possible recursive locking detected 5.16.0-syzkaller #0 Not tainted -------------------------------------------- kworker/u4:1/30382 is trying to acquire lock: ffff88807bcf93b8 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] ffff88807bcf93b8 (&br->multicast_lock){+.-.}-{2:2}, at: br_ip6_multicast_query net/bridge/br_multicast.c:3341 [inline] ffff88807bcf93b8 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_ipv6_rcv net/bridge/br_multicast.c:3737 [inline] ffff88807bcf93b8 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_rcv+0x16dc/0x6230 net/bridge/br_multicast.c:3792 but task is already holding lock: ffff8880734093b8 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] ffff8880734093b8 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_port_query_expired+0x61/0x360 net/bridge/br_multicast.c:1742 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&br->multicast_lock); lock(&br->multicast_lock); *** DEADLOCK *** May be due to missing lock nesting notation 8 locks held by kworker/u4:1/30382: #0: ffff888023066938 ((wq_completion)bat_events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888023066938 ((wq_completion)bat_events){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888023066938 ((wq_completion)bat_events){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff888023066938 ((wq_completion)bat_events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline] #0: ffff888023066938 ((wq_completion)bat_events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline] #0: ffff888023066938 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work+0x896/0x1660 kernel/workqueue.c:2269 #1: ffffc90003dc7db0 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1660 kernel/workqueue.c:2273 #2: ffffc90000007d90 ((&pmctx->ip6_own_query.timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:35 [inline] #2: ffffc90000007d90 ((&pmctx->ip6_own_query.timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x6b0 kernel/time/timer.c:1411 #3: ffff8880734093b8 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] #3: ffff8880734093b8 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_port_query_expired+0x61/0x360 net/bridge/br_multicast.c:1742 #4: ffffffff8bb845c0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1e3/0x3660 net/core/dev.c:4040 #5: ffffffff8bb84620 (rcu_read_lock){....}-{1:2}, at: is_netpoll_tx_blocked include/net/bonding.h:109 [inline] #5: ffffffff8bb84620 (rcu_read_lock){....}-{1:2}, at: bond_start_xmit+0x88/0x1220 drivers/net/bonding/bond_main.c:5132 #6: ffffffff8bb845c0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1e3/0x3660 net/core/dev.c:4040 #7: ffffffff8bb84620 (rcu_read_lock){....}-{1:2}, at: br_dev_xmit+0x0/0x16c0 net/bridge/br_device.c:309 stack backtrace: CPU: 0 PID: 30382 Comm: kworker/u4:1 Not tainted 5.16.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker 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+0x149/0x3ab kernel/locking/lockdep.c:5027 lock_acquire kernel/locking/lockdep.c:5637 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602 __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] br_ip6_multicast_query net/bridge/br_multicast.c:3341 [inline] br_multicast_ipv6_rcv net/bridge/br_multicast.c:3737 [inline] br_multicast_rcv+0x16dc/0x6230 net/bridge/br_multicast.c:3792 br_dev_xmit+0x6f6/0x16c0 net/bridge/br_device.c:89 __netdev_start_xmit include/linux/netdevice.h:4682 [inline] netdev_start_xmit include/linux/netdevice.h:4696 [inline] xmit_one net/core/dev.c:3473 [inline] dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3489 __dev_queue_xmit+0x2985/0x3660 net/core/dev.c:4116 bond_dev_queue_xmit+0xc3/0x170 drivers/net/bonding/bond_main.c:306 bond_3ad_xor_xmit drivers/net/bonding/bond_main.c:4875 [inline] __bond_start_xmit drivers/net/bonding/bond_main.c:5109 [inline] bond_start_xmit+0xb01/0x1220 drivers/net/bonding/bond_main.c:5137 __netdev_start_xmit include/linux/netdevice.h:4682 [inline] netdev_start_xmit include/linux/netdevice.h:4696 [inline] xmit_one net/core/dev.c:3473 [inline] dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3489 __dev_queue_xmit+0x2985/0x3660 net/core/dev.c:4116 br_dev_queue_push_xmit+0x25c/0x740 net/bridge/br_forward.c:53 NF_HOOK include/linux/netfilter.h:307 [inline] __br_multicast_send_query+0x118d/0x3ab0 net/bridge/br_multicast.c:1646 br_multicast_send_query+0x266/0x4b0 net/bridge/br_multicast.c:1725 br_multicast_port_query_expired+0x2c3/0x360 net/bridge/br_multicast.c:1750 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x67c/0xa30 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 do_softirq.part.0+0xde/0x130 kernel/softirq.c:459 do_softirq kernel/softirq.c:451 [inline] __local_bh_enable_ip+0x102/0x120 kernel/softirq.c:383 spin_unlock_bh include/linux/spinlock.h:394 [inline] batadv_nc_purge_paths+0x2a5/0x3a0 net/batman-adv/network-coding.c:471 batadv_nc_worker+0x8f9/0xfa0 net/batman-adv/network-coding.c:720 process_one_work+0x9b2/0x1660 kernel/workqueue.c:2298 worker_thread+0x65d/0x1130 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295