============================================ WARNING: possible recursive locking detected 6.8.0-syzkaller-05204-g237bb5f7f7f5 #0 Not tainted -------------------------------------------- syz-executor.3/17616 is trying to acquire lock: ffff888078d193e0 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff888078d193e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_ip6_multicast_query net/bridge/br_multicast.c:3523 [inline] ffff888078d193e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_ipv6_rcv net/bridge/br_multicast.c:3919 [inline] ffff888078d193e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_rcv+0x30e2/0x8180 net/bridge/br_multicast.c:3974 but task is already holding lock: ffff8880225253e0 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff8880225253e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_port_query_expired+0x64/0x3b0 net/bridge/br_multicast.c:1905 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.3/17616: #0: ffffffff8f3f8628 (nf_ct_proto_mutex){+.+.}-{3:3}, at: nf_ct_netns_do_put net/netfilter/nf_conntrack_proto.c:531 [inline] #0: ffffffff8f3f8628 (nf_ct_proto_mutex){+.+.}-{3:3}, at: nf_ct_netns_put+0x62/0x510 net/netfilter/nf_conntrack_proto.c:613 #1: ffffffff8f3f0b68 (nf_hook_mutex){+.+.}-{3:3}, at: __nf_unregister_net_hook+0x91/0x800 net/netfilter/core.c:498 #2: ffffc90000007c00 ((&pmctx->ip6_own_query.timer)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x600 kernel/time/timer.c:1789 #3: ffff8880225253e0 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #3: ffff8880225253e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_port_query_expired+0x64/0x3b0 net/bridge/br_multicast.c:1905 #4: ffffffff8e131980 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #4: ffffffff8e131980 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:802 [inline] #4: ffffffff8e131980 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2c4/0x3b10 net/core/dev.c:4260 #5: ffffffff8e131980 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #5: ffffffff8e131980 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:802 [inline] #5: ffffffff8e131980 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x2c4/0x3b10 net/core/dev.c:4260 #6: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #6: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #6: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: br_dev_xmit+0x1b9/0x1a10 net/bridge/br_device.c:44 stack backtrace: CPU: 0 PID: 17616 Comm: syz-executor.3 Not tainted 6.8.0-syzkaller-05204-g237bb5f7f7f5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain+0x15c1/0x58e0 kernel/locking/lockdep.c:3856 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] br_ip6_multicast_query net/bridge/br_multicast.c:3523 [inline] br_multicast_ipv6_rcv net/bridge/br_multicast.c:3919 [inline] br_multicast_rcv+0x30e2/0x8180 net/bridge/br_multicast.c:3974 br_dev_xmit+0xb17/0x1a10 net/bridge/br_device.c:90 __netdev_start_xmit include/linux/netdevice.h:4903 [inline] netdev_start_xmit include/linux/netdevice.h:4917 [inline] xmit_one net/core/dev.c:3531 [inline] dev_hard_start_xmit+0x26a/0x790 net/core/dev.c:3547 __dev_queue_xmit+0x19f4/0x3b10 net/core/dev.c:4335 dev_queue_xmit include/linux/netdevice.h:3091 [inline] vlan_dev_hard_start_xmit+0x36c/0x5f0 net/8021q/vlan_dev.c:125 __netdev_start_xmit include/linux/netdevice.h:4903 [inline] netdev_start_xmit include/linux/netdevice.h:4917 [inline] xmit_one net/core/dev.c:3531 [inline] dev_hard_start_xmit+0x26a/0x790 net/core/dev.c:3547 __dev_queue_xmit+0x19f4/0x3b10 net/core/dev.c:4335 dev_queue_xmit include/linux/netdevice.h:3091 [inline] br_dev_queue_push_xmit+0x701/0x8d0 net/bridge/br_forward.c:53 NF_HOOK include/linux/netfilter.h:314 [inline] __br_multicast_send_query+0x2ecb/0x4750 net/bridge/br_multicast.c:1809 br_multicast_send_query+0x4ee/0x6b0 net/bridge/br_multicast.c:1888 br_multicast_port_query_expired+0x2d4/0x3b0 net/bridge/br_multicast.c:1913 call_timer_fn+0x17e/0x600 kernel/time/timer.c:1792 expire_timers kernel/time/timer.c:1843 [inline] __run_timers kernel/time/timer.c:2408 [inline] __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2419 run_timer_base kernel/time/timer.c:2428 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2438 __do_softirq+0x2bc/0x943 kernel/softirq.c:554 invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633 irq_exit_rcu+0x9/0x30 kernel/softirq.c:645 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:stack_trace_consume_entry+0xb/0x280 kernel/stacktrace.c:83 Code: ef 09 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 <41> 54 53 48 83 ec 18 48 89 fb 48 ba 00 00 00 00 00 fc ff df 4c 8d RSP: 0018:ffffc90003f3edb8 EFLAGS: 00000286 RAX: 0000000000000000 RBX: ffffffff893b4435 RCX: ffff888067015a00 RDX: 0000000000000000 RSI: ffffffff893b4435 RDI: ffffc90003f3eec0 RBP: ffffc90003f3ee70 R08: ffffffff81372702 R09: ffffffff8140a8df R10: 0000000000000003 R11: ffffffff8180dbc0 R12: ffff888067015a00 R13: ffffffff8180dbc0 R14: ffffc90003f3eec0 R15: ffffc90003f3ede0 arch_stack_walk+0x143/0x1b0 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slub.c:3981 [inline] __kmalloc_node+0x251/0x4e0 mm/slub.c:3988 kmalloc_node include/linux/slab.h:610 [inline] kvmalloc_node+0x72/0x190 mm/util.c:634 kvmalloc include/linux/slab.h:728 [inline] kvzalloc include/linux/slab.h:736 [inline] allocate_hook_entries_size net/netfilter/core.c:61 [inline] __nf_hook_entries_try_shrink+0x330/0x730 net/netfilter/core.c:260 __nf_unregister_net_hook+0x5cf/0x800 net/netfilter/core.c:520 nf_unregister_net_hooks+0xd0/0x140 net/netfilter/core.c:613 nf_ct_netns_do_put net/netfilter/nf_conntrack_proto.c:553 [inline] nf_ct_netns_put+0x219/0x510 net/netfilter/nf_conntrack_proto.c:613 ebt_cleanup_match net/bridge/netfilter/ebtables.c:632 [inline] ebt_cleanup_entry+0x57c/0x930 net/bridge/netfilter/ebtables.c:667 do_replace_finish+0x1430/0x1b10 net/bridge/netfilter/ebtables.c:1083 do_replace+0x411/0x570 net/bridge/netfilter/ebtables.c:1151 do_ebt_set_ctl+0x304/0x17b0 net/bridge/netfilter/ebtables.c:2521 nf_setsockopt+0x295/0x2c0 net/netfilter/nf_sockopt.c:101 do_sock_setsockopt+0x3af/0x720 net/socket.c:2311 __sys_setsockopt+0x1ae/0x250 net/socket.c:2334 __do_sys_setsockopt net/socket.c:2343 [inline] __se_sys_setsockopt net/socket.c:2340 [inline] __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7f412fe7fafa Code: ff ff ff c3 0f 1f 40 00 48 c7 c2 b0 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 49 89 ca b8 36 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 b0 ff ff ff f7 RSP: 002b:00007ffe06e8a7b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f412ff791a0 RCX: 00007f412fe7fafa RDX: 0000000000000080 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000108 R09: 00007ffe06e8abe7 R10: 00007f412ff79128 R11: 0000000000000246 R12: 00007ffe06e8a7e0 R13: 00007ffe06e8a7dc R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: ef out %eax,(%dx) 1: 09 66 2e or %esp,0x2e(%rsi) 4: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1) b: 00 c: 0f 1f 00 nopl (%rax) f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: 90 nop 1c: 90 nop 1d: 90 nop 1e: 90 nop 1f: f3 0f 1e fa endbr64 23: 55 push %rbp 24: 41 57 push %r15 26: 41 56 push %r14 28: 41 55 push %r13 * 2a: 41 54 push %r12 <-- trapping instruction 2c: 53 push %rbx 2d: 48 83 ec 18 sub $0x18,%rsp 31: 48 89 fb mov %rdi,%rbx 34: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx 3b: fc ff df 3e: 4c rex.WR 3f: 8d .byte 0x8d