============================================ WARNING: possible recursive locking detected 5.16.0-rc2-syzkaller #0 Not tainted -------------------------------------------- syz-executor.0/6877 is trying to acquire lock: ffff8880282fd330 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] ffff8880282fd330 (&br->multicast_lock){+.-.}-{2:2}, at: br_ip6_multicast_query net/bridge/br_multicast.c:3341 [inline] ffff8880282fd330 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_ipv6_rcv net/bridge/br_multicast.c:3737 [inline] ffff8880282fd330 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_rcv+0x16dc/0x6230 net/bridge/br_multicast.c:3792 but task is already holding lock: ffff888041a81330 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] ffff888041a81330 (&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 9 locks held by syz-executor.0/6877: #0: ffffc90005697cb8 ((&pmctx->ip6_own_query.timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:35 [inline] #0: ffffc90005697cb8 ((&pmctx->ip6_own_query.timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x6b0 kernel/time/timer.c:1411 #1: ffff888041a81330 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] #1: ffff888041a81330 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_port_query_expired+0x61/0x360 net/bridge/br_multicast.c:1742 #2: ffffffff8bb83c40 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1e3/0x3630 net/core/dev.c:4153 #3: ffffffff8bb83ca0 (rcu_read_lock){....}-{1:2}, at: is_netpoll_tx_blocked include/net/bonding.h:109 [inline] #3: ffffffff8bb83ca0 (rcu_read_lock){....}-{1:2}, at: bond_start_xmit+0x88/0x1220 drivers/net/bonding/bond_main.c:5091 #4: ffffffff8bb83c40 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1e3/0x3630 net/core/dev.c:4153 #5: ffffffff8bb83ca0 (rcu_read_lock){....}-{1:2}, at: is_netpoll_tx_blocked include/net/bonding.h:109 [inline] #5: ffffffff8bb83ca0 (rcu_read_lock){....}-{1:2}, at: bond_start_xmit+0x88/0x1220 drivers/net/bonding/bond_main.c:5091 #6: ffffffff8bb83c40 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1e3/0x3630 net/core/dev.c:4153 #7: ffffffff8bb83c40 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1e3/0x3630 net/core/dev.c:4153 #8: ffffffff8bb83ca0 (rcu_read_lock){....}-{1:2}, at: br_dev_xmit+0x0/0x16c0 net/bridge/br_device.c:309 stack backtrace: CPU: 1 PID: 6877 Comm: syz-executor.0 Not tainted 5.16.0-rc2-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+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:4987 [inline] netdev_start_xmit include/linux/netdevice.h:5001 [inline] xmit_one net/core/dev.c:3590 [inline] dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3606 __dev_queue_xmit+0x299a/0x3630 net/core/dev.c:4226 vlan_dev_hard_start_xmit+0x1b3/0x670 net/8021q/vlan_dev.c:124 __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+0x1eb/0x920 net/core/dev.c:3606 __dev_queue_xmit+0x299a/0x3630 net/core/dev.c:4226 bond_dev_queue_xmit+0xc3/0x170 drivers/net/bonding/bond_main.c:304 bond_3ad_xor_xmit drivers/net/bonding/bond_main.c:4834 [inline] __bond_start_xmit drivers/net/bonding/bond_main.c:5068 [inline] bond_start_xmit+0xb01/0x1220 drivers/net/bonding/bond_main.c:5096 __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+0x1eb/0x920 net/core/dev.c:3606 __dev_queue_xmit+0x299a/0x3630 net/core/dev.c:4226 bond_dev_queue_xmit+0xc3/0x170 drivers/net/bonding/bond_main.c:304 bond_3ad_xor_xmit drivers/net/bonding/bond_main.c:4834 [inline] __bond_start_xmit drivers/net/bonding/bond_main.c:5068 [inline] bond_start_xmit+0xb01/0x1220 drivers/net/bonding/bond_main.c:5096 __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+0x1eb/0x920 net/core/dev.c:3606 __dev_queue_xmit+0x299a/0x3630 net/core/dev.c:4226 br_dev_queue_push_xmit+0x25a/0x740 net/bridge/br_forward.c:53 NF_HOOK include/linux/netfilter.h:307 [inline] __br_multicast_send_query+0x118d/0x3aa0 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+0x675/0xa20 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 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x45/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0033:0x7f0f7bd91ba6 Code: d0 c1 e8 10 44 31 d0 83 f0 3d 8d 04 c0 89 c7 c1 ef 04 31 f8 69 c0 2d eb d4 27 41 31 c0 c1 e8 0f 41 31 c0 80 3d eb e7 09 01 00 <0f> 85 74 ff ff ff bd 01 00 00 00 45 8d 58 04 44 89 c0 41 89 c2 41 RSP: 002b:00007fff81cc9b10 EFLAGS: 00000246 RAX: 0000000000017775 RBX: 00007f0f7bb5b008 RCX: 0000001b2d320000 RDX: 0000001b2d321ed4 RSI: ffffffff83a30aaa RDI: 000000000a0bfd21 RBP: 0000000000000001 R08: 000000003818a3a1 R09: 0000001b2d321984 R10: ffffffff83a30a81 R11: 0000000091492e94 R12: 0000000000015816 R13: 00007f0f7beeb000 R14: ffffffff83a30aaa R15: 00007f0f7bef6ff0