============================================ WARNING: possible recursive locking detected 5.16.0-syzkaller #0 Not tainted -------------------------------------------- syz-executor.3/25458 is trying to acquire lock: ffff8880791cd3b8 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] ffff8880791cd3b8 (&br->multicast_lock){+.-.}-{2:2}, at: br_ip6_multicast_query net/bridge/br_multicast.c:3341 [inline] ffff8880791cd3b8 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_ipv6_rcv net/bridge/br_multicast.c:3737 [inline] ffff8880791cd3b8 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_rcv+0x16dc/0x6230 net/bridge/br_multicast.c:3792 but task is already holding lock: ffff888076da13b8 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] ffff888076da13b8 (&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 7 locks held by syz-executor.3/25458: #0: ffffffff8d306bd0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x2f5/0x760 net/core/net_namespace.c:468 #1: ffffc90000dc0d70 ((&pmctx->ip6_own_query.timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:35 [inline] #1: ffffc90000dc0d70 ((&pmctx->ip6_own_query.timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x6b0 kernel/time/timer.c:1411 #2: ffff888076da13b8 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] #2: ffff888076da13b8 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_port_query_expired+0x61/0x360 net/bridge/br_multicast.c:1742 #3: ffffffff8bb845c0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1e3/0x3660 net/core/dev.c:4040 #4: ffffffff8bb84620 (rcu_read_lock){....}-{1:2}, at: is_netpoll_tx_blocked include/net/bonding.h:109 [inline] #4: ffffffff8bb84620 (rcu_read_lock){....}-{1:2}, at: bond_start_xmit+0x88/0x1220 drivers/net/bonding/bond_main.c:5132 #5: ffffffff8bb845c0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1e3/0x3660 net/core/dev.c:4040 #6: ffffffff8bb84620 (rcu_read_lock){....}-{1:2}, at: br_dev_xmit+0x0/0x16c0 net/bridge/br_device.c:309 stack backtrace: CPU: 1 PID: 25458 Comm: syz-executor.3 Not tainted 5.16.0-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+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 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__might_resched+0x1a/0x2c0 kernel/sched/core.c:9493 Code: 80 5b 5d c3 e8 c7 c4 f8 07 0f 1f 80 00 00 00 00 41 56 41 55 41 54 41 89 f4 be ff ff ff ff 55 48 89 fd 48 c7 c7 c0 45 b8 8b 53 <89> d3 e8 3f c8 f8 07 85 c0 0f 85 d3 01 00 00 be ff ff ff ff 48 c7 RSP: 0018:ffffc90006617b70 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 000000000007ffff RCX: 0000000000000000 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff8bb845c0 RBP: ffffffff8aba07c0 R08: 000000000007ffff R09: 0000000000000000 R10: ffffffff87aec327 R11: 0000000000000000 R12: 000000000000010b R13: ffffc90006617d08 R14: 0000000000000002 R15: dffffc0000000000 inet_twsk_purge+0xe8/0x7d0 net/ipv4/inet_timewait_sock.c:267 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:171 setup_net+0x779/0xbb0 net/core/net_namespace.c:351 copy_net_ns+0x318/0x760 net/core/net_namespace.c:472 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x920 kernel/fork.c:3075 __do_sys_unshare kernel/fork.c:3146 [inline] __se_sys_unshare kernel/fork.c:3144 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3144 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f1e20bcffe9 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:00007f1e1f545168 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f1e20ce2f60 RCX: 00007f1e20bcffe9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006c060000 RBP: 00007f1e20c2a08d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe3afd0adf R14: 00007f1e1f545300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 80 5b 5d c3 sbbb $0xc3,0x5d(%rbx) 4: e8 c7 c4 f8 07 callq 0x7f8c4d0 9: 0f 1f 80 00 00 00 00 nopl 0x0(%rax) 10: 41 56 push %r14 12: 41 55 push %r13 14: 41 54 push %r12 16: 41 89 f4 mov %esi,%r12d 19: be ff ff ff ff mov $0xffffffff,%esi 1e: 55 push %rbp 1f: 48 89 fd mov %rdi,%rbp 22: 48 c7 c7 c0 45 b8 8b mov $0xffffffff8bb845c0,%rdi 29: 53 push %rbx * 2a: 89 d3 mov %edx,%ebx <-- trapping instruction 2c: e8 3f c8 f8 07 callq 0x7f8c870 31: 85 c0 test %eax,%eax 33: 0f 85 d3 01 00 00 jne 0x20c 39: be ff ff ff ff mov $0xffffffff,%esi 3e: 48 rex.W 3f: c7 .byte 0xc7