============================================ WARNING: possible recursive locking detected 6.5.0-rc7-syzkaller-00004-gf7757129e3de #0 Not tainted -------------------------------------------- syz-executor.2/13310 is trying to acquire lock: ffff8880a2bcd330 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff8880a2bcd330 (&br->multicast_lock){+.-.}-{2:2}, at: br_ip6_multicast_query net/bridge/br_multicast.c:3518 [inline] ffff8880a2bcd330 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_ipv6_rcv net/bridge/br_multicast.c:3914 [inline] ffff8880a2bcd330 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_rcv+0x21b6/0x6730 net/bridge/br_multicast.c:3969 but task is already holding lock: ffff88809f50d330 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff88809f50d330 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_port_query_expired+0x61/0x350 net/bridge/br_multicast.c:1900 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 syz-executor.2/13310: #0: ffff88809ffeb2f8 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read include/linux/mm.h:654 [inline] #0: ffff88809ffeb2f8 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x215/0xaa0 mm/memory.c:5393 #1: ffffc90000007ce0 ((&pmctx->ip6_own_query.timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:31 [inline] #1: ffffc90000007ce0 ((&pmctx->ip6_own_query.timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x580 kernel/time/timer.c:1690 #2: ffff88809f50d330 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #2: ffff88809f50d330 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_port_query_expired+0x61/0x350 net/bridge/br_multicast.c:1900 #3: ffffffff8c9a73a0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x257/0x3f20 net/core/dev.c:4120 #4: ffffffff8c9a7400 (rcu_read_lock){....}-{1:2}, at: is_netpoll_tx_blocked include/net/bonding.h:108 [inline] #4: ffffffff8c9a7400 (rcu_read_lock){....}-{1:2}, at: bond_start_xmit+0x8e/0x1260 drivers/net/bonding/bond_main.c:5503 #5: ffffffff8c9a73a0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x257/0x3f20 net/core/dev.c:4120 #6: ffffffff8c9a73a0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x257/0x3f20 net/core/dev.c:4120 #7: ffffffff8c9a7400 (rcu_read_lock){....}-{1:2}, at: arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline] #7: ffffffff8c9a7400 (rcu_read_lock){....}-{1:2}, at: br_tc_skb_miss_set net/bridge/br_private.h:763 [inline] #7: ffffffff8c9a7400 (rcu_read_lock){....}-{1:2}, at: br_dev_xmit+0xf0/0x1970 net/bridge/br_device.c:42 stack backtrace: CPU: 0 PID: 13310 Comm: syz-executor.2 Not tainted 6.5.0-rc7-syzkaller-00004-gf7757129e3de #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 check_deadlock kernel/locking/lockdep.c:3070 [inline] validate_chain kernel/locking/lockdep.c:3863 [inline] __lock_acquire+0x2971/0x5de0 kernel/locking/lockdep.c:5144 lock_acquire kernel/locking/lockdep.c:5761 [inline] lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5726 __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:3518 [inline] br_multicast_ipv6_rcv net/bridge/br_multicast.c:3914 [inline] br_multicast_rcv+0x21b6/0x6730 net/bridge/br_multicast.c:3969 br_dev_xmit+0x786/0x1970 net/bridge/br_device.c:90 __netdev_start_xmit include/linux/netdevice.h:4910 [inline] netdev_start_xmit include/linux/netdevice.h:4924 [inline] xmit_one net/core/dev.c:3537 [inline] dev_hard_start_xmit+0x13d/0x6c0 net/core/dev.c:3553 __dev_queue_xmit+0xa55/0x3f20 net/core/dev.c:4203 dev_queue_xmit include/linux/netdevice.h:3088 [inline] vlan_dev_hard_start_xmit+0x3af/0x5c0 net/8021q/vlan_dev.c:125 __netdev_start_xmit include/linux/netdevice.h:4910 [inline] netdev_start_xmit include/linux/netdevice.h:4924 [inline] xmit_one net/core/dev.c:3537 [inline] dev_hard_start_xmit+0x13d/0x6c0 net/core/dev.c:3553 __dev_queue_xmit+0xa55/0x3f20 net/core/dev.c:4203 dev_queue_xmit include/linux/netdevice.h:3088 [inline] bond_dev_queue_xmit+0xc9/0x170 drivers/net/bonding/bond_main.c:308 bond_3ad_xor_xmit drivers/net/bonding/bond_main.c:5226 [inline] __bond_start_xmit drivers/net/bonding/bond_main.c:5480 [inline] bond_start_xmit+0x457/0x1260 drivers/net/bonding/bond_main.c:5508 __netdev_start_xmit include/linux/netdevice.h:4910 [inline] netdev_start_xmit include/linux/netdevice.h:4924 [inline] xmit_one net/core/dev.c:3537 [inline] dev_hard_start_xmit+0x13d/0x6c0 net/core/dev.c:3553 __dev_queue_xmit+0xa55/0x3f20 net/core/dev.c:4203 dev_queue_xmit include/linux/netdevice.h:3088 [inline] br_dev_queue_push_xmit+0x26e/0x7b0 net/bridge/br_forward.c:53 NF_HOOK include/linux/netfilter.h:303 [inline] __br_multicast_send_query+0x238b/0x4110 net/bridge/br_multicast.c:1804 br_multicast_send_query+0x2ce/0x540 net/bridge/br_multicast.c:1883 br_multicast_port_query_expired+0x288/0x350 net/bridge/br_multicast.c:1908 call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700 expire_timers kernel/time/timer.c:1751 [inline] __run_timers+0x764/0xb10 kernel/time/timer.c:2022 run_timer_softirq+0x58/0xd0 kernel/time/timer.c:2035 __do_softirq+0x218/0x965 kernel/softirq.c:553 invoke_softirq kernel/softirq.c:427 [inline] __irq_exit_rcu kernel/softirq.c:632 [inline] irq_exit_rcu+0xb7/0x120 kernel/softirq.c:644 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1109 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:__sanitizer_cov_trace_pc+0x50/0x70 kernel/kcov.c:212 Code: 0e 85 c9 74 35 8b 82 04 16 00 00 85 c0 74 2b 8b 82 e0 15 00 00 83 f8 02 75 20 48 8b 8a e8 15 00 00 8b 92 e4 15 00 00 48 8b 01 <48> 83 c0 01 48 39 d0 73 07 48 89 01 48 89 34 c1 c3 66 66 2e 0f 1f RSP: 0000:ffffc9000cb47d20 EFLAGS: 00000246 RAX: 000000000003ffff RBX: 00000000a3a3b067 RCX: ffffc90023e81000 RDX: 0000000000040000 RSI: ffffffff81c5eb6c RDI: 0000000000000007 RBP: 0400000000000000 R08: 0000000000000007 R09: 0000000000000080 R10: 0000000000000000 R11: 0000000000000000 R12: 000000009848f007 R13: dffffc0000000000 R14: ffff88802c6e6f00 R15: 0000000000000020 pud_devmap arch/x86/include/asm/pgtable.h:263 [inline] __handle_mm_fault+0x36c/0x3b80 mm/memory.c:5023 handle_mm_fault+0x2ab/0x9d0 mm/memory.c:5233 do_user_addr_fault+0x2e7/0xfc0 arch/x86/mm/fault.c:1343 handle_page_fault arch/x86/mm/fault.c:1486 [inline] exc_page_fault+0x5c/0xd0 arch/x86/mm/fault.c:1542 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570 RIP: 0033:0x7f4fcee286e6 Code: f0 72 6e 48 63 cd 48 01 c1 49 39 4f 08 72 4c 8d 4d ff 85 ed 74 33 66 0f 1f 44 00 00 48 39 f0 72 1b 4d 8b 07 49 89 c1 49 29 f1 <47> 0f b6 0c 08 45 84 c9 74 08 45 88 0c 00 49 8b 47 10 48 83 c0 01 RSP: 002b:00007f4fcfb6c520 EFLAGS: 00010206 RAX: 0000000000710001 RBX: 00007f4fcfb6c5c0 RCX: 0000000000000024 RDX: 0000000000000005 RSI: 0000000000000001 RDI: 00007f4fcfb6c660 RBP: 0000000000000102 R08: 00007f4fc55ff000 R09: 0000000000710000 R10: 0000000000000000 R11: 00007f4fcfb6c5d0 R12: 0000000000000001 R13: 00007f4fceeea360 R14: 0000000000000000 R15: 00007f4fcfb6c660 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 85 c9 test %ecx,%ecx 2: 74 35 je 0x39 4: 8b 82 04 16 00 00 mov 0x1604(%rdx),%eax a: 85 c0 test %eax,%eax c: 74 2b je 0x39 e: 8b 82 e0 15 00 00 mov 0x15e0(%rdx),%eax 14: 83 f8 02 cmp $0x2,%eax 17: 75 20 jne 0x39 19: 48 8b 8a e8 15 00 00 mov 0x15e8(%rdx),%rcx 20: 8b 92 e4 15 00 00 mov 0x15e4(%rdx),%edx 26: 48 8b 01 mov (%rcx),%rax * 29: 48 83 c0 01 add $0x1,%rax <-- trapping instruction 2d: 48 39 d0 cmp %rdx,%rax 30: 73 07 jae 0x39 32: 48 89 01 mov %rax,(%rcx) 35: 48 89 34 c1 mov %rsi,(%rcx,%rax,8) 39: c3 ret 3a: 66 data16 3b: 66 data16 3c: 2e cs 3d: 0f .byte 0xf 3e: 1f (bad)