============================================ WARNING: possible recursive locking detected 6.3.0-rc3-syzkaller-00016-g2faac9a98f01 #0 Not tainted -------------------------------------------- dhcpcd-run-hook/5187 is trying to acquire lock: ffff88807ab15338 (&br->multicast_lock ){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline] ){+.-.}-{2:2}, at: br_ip6_multicast_query net/bridge/br_multicast.c:3518 [inline] ){+.-.}-{2:2}, at: br_multicast_ipv6_rcv net/bridge/br_multicast.c:3914 [inline] ){+.-.}-{2:2}, at: br_multicast_rcv+0x202d/0x6850 net/bridge/br_multicast.c:3969 but task is already holding lock: ffff88807ab11338 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline] ffff88807ab11338 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_port_query_expired+0x61/0x360 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 6 locks held by dhcpcd-run-hook/5187: #0: ffff8880781e8ad8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #0: ffff8880781e8ad8 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x159/0x280 mm/util.c:540 #1: ffffc900001e0d70 ((&pmctx->ip6_own_query.timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:31 [inline] #1: ffffc900001e0d70 ((&pmctx->ip6_own_query.timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x580 kernel/time/timer.c:1690 #2: ffff88807ab11338 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:350 [inline] #2: ffff88807ab11338 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_port_query_expired+0x61/0x360 net/bridge/br_multicast.c:1900 #3: ffffffff8c795660 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x23f/0x3c40 net/core/dev.c:4163 #4: ffffffff8c795660 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x23f/0x3c40 net/core/dev.c:4163 #5: ffffffff8c7956c0 (rcu_read_lock){....}-{1:2}, at: br_dev_xmit+0x4/0x16c0 net/bridge/br_device.c:29 stack backtrace: CPU: 1 PID: 5187 Comm: dhcpcd-run-hook Not tainted 6.3.0-rc3-syzkaller-00016-g2faac9a98f01 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2991 [inline] check_deadlock kernel/locking/lockdep.c:3034 [inline] validate_chain kernel/locking/lockdep.c:3819 [inline] __lock_acquire+0x1362/0x5d40 kernel/locking/lockdep.c:5056 lock_acquire kernel/locking/lockdep.c:5669 [inline] lock_acquire+0x1af/0x520 kernel/locking/lockdep.c:5634 __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:350 [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+0x202d/0x6850 net/bridge/br_multicast.c:3969 br_dev_xmit+0x726/0x16c0 net/bridge/br_device.c:89 __netdev_start_xmit include/linux/netdevice.h:4883 [inline] netdev_start_xmit include/linux/netdevice.h:4897 [inline] xmit_one net/core/dev.c:3580 [inline] dev_hard_start_xmit+0x187/0x700 net/core/dev.c:3596 __dev_queue_xmit+0x2ce4/0x3c40 net/core/dev.c:4246 dev_queue_xmit include/linux/netdevice.h:3053 [inline] vlan_dev_hard_start_xmit+0x1bc/0x5c0 net/8021q/vlan_dev.c:124 __netdev_start_xmit include/linux/netdevice.h:4883 [inline] netdev_start_xmit include/linux/netdevice.h:4897 [inline] xmit_one net/core/dev.c:3580 [inline] dev_hard_start_xmit+0x187/0x700 net/core/dev.c:3596 __dev_queue_xmit+0x2ce4/0x3c40 net/core/dev.c:4246 dev_queue_xmit include/linux/netdevice.h:3053 [inline] br_dev_queue_push_xmit+0x26e/0x740 net/bridge/br_forward.c:53 NF_HOOK include/linux/netfilter.h:302 [inline] __br_multicast_send_query+0x11c6/0x3c10 net/bridge/br_multicast.c:1804 br_multicast_send_query+0x266/0x4b0 net/bridge/br_multicast.c:1883 br_multicast_port_query_expired+0x2c3/0x360 net/bridge/br_multicast.c:1908 call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700 expire_timers+0x29b/0x4b0 kernel/time/timer.c:1751 __run_timers kernel/time/timer.c:2022 [inline] __run_timers kernel/time/timer.c:1995 [inline] run_timer_softirq+0x326/0x910 kernel/time/timer.c:2035 __do_softirq+0x1d4/0x905 kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x114/0x190 kernel/softirq.c:650 irq_exit_rcu+0x9/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x97/0xc0 arch/x86/kernel/apic/apic.c:1107 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:__unwind_start+0x37d/0x800 arch/x86/kernel/unwind_orc.c:688 Code: 8b 77 28 4c 89 e1 4c 89 fa 48 89 ef e8 bc ee f4 ff 85 c0 0f 85 5e ff ff ff e9 eb fe ff ff 65 48 8b 04 25 80 b8 03 00 48 39 c5 <0f> 84 10 02 00 00 48 8d bd d8 17 00 00 48 b8 00 00 00 00 00 fc ff RSP: 0018:ffffc90003fbf400 EFLAGS: 00000246 RAX: ffff8880236d1d40 RBX: ffffc90003fbf4d8 RCX: 0000000000000000 RDX: 1ffff920007f7e8f RSI: 0000000000000000 RDI: ffffc90003fbf4b0 RBP: ffff8880236d1d40 R08: 000000007fbfd3de R09: ffffc90003fbf450 R10: fffffbfff1cef73a R11: 0000000000094001 R12: 0000000000000000 R13: ffffc90003fbf478 R14: ffff8880236d1d40 R15: ffffc90003fbf450 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0x60/0xf0 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x90/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 __kasan_slab_alloc+0x7f/0x90 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:186 [inline] slab_post_alloc_hook mm/slab.h:769 [inline] kmem_cache_alloc_bulk+0x424/0x860 mm/slub.c:4034 mt_alloc_bulk lib/maple_tree.c:164 [inline] mas_alloc_nodes+0x276/0x8a0 lib/maple_tree.c:1263 mas_node_count_gfp lib/maple_tree.c:1318 [inline] mas_preallocate+0x1bb/0x360 lib/maple_tree.c:5731 vma_iter_prealloc mm/internal.h:972 [inline] __split_vma+0x1b7/0x810 mm/mmap.c:2177 do_vmi_align_munmap+0x22a/0xf60 mm/mmap.c:2302 do_vmi_munmap+0x26e/0x2c0 mm/mmap.c:2452 mmap_region+0x1ee/0x2690 mm/mmap.c:2500 do_mmap+0x831/0xf60 mm/mmap.c:1364 vm_mmap_pgoff+0x1af/0x280 mm/util.c:542 ksys_mmap_pgoff+0x41f/0x5a0 mm/mmap.c:1410 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f0a6f4881f2 Code: 04 00 00 5b 5d 41 5c c3 41 f7 c1 ff 0f 00 00 75 27 55 48 89 fd 53 89 cb 48 85 ff 74 33 41 89 da 48 89 ef b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 56 5b 5d c3 0f 1f 00 c7 05 9e 1f 01 00 16 00 RSP: 002b:00007ffc897ce548 EFLAGS: 00000206 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000000000000812 RCX: 00007f0a6f4881f2 RDX: 0000000000000005 RSI: 000000000013f000 RDI: 00007f0a6f206000 RBP: 00007f0a6f206000 R08: 0000000000000003 R09: 0000000000022000 R10: 0000000000000812 R11: 0000000000000206 R12: 00007ffc897ce560 R13: 00007ffc897ce590 R14: 0000000000000005 R15: 00007f0a6f466500 ---------------- Code disassembly (best guess): 0: 8b 77 28 mov 0x28(%rdi),%esi 3: 4c 89 e1 mov %r12,%rcx 6: 4c 89 fa mov %r15,%rdx 9: 48 89 ef mov %rbp,%rdi c: e8 bc ee f4 ff callq 0xfff4eecd 11: 85 c0 test %eax,%eax 13: 0f 85 5e ff ff ff jne 0xffffff77 19: e9 eb fe ff ff jmpq 0xffffff09 1e: 65 48 8b 04 25 80 b8 mov %gs:0x3b880,%rax 25: 03 00 27: 48 39 c5 cmp %rax,%rbp * 2a: 0f 84 10 02 00 00 je 0x240 <-- trapping instruction 30: 48 8d bd d8 17 00 00 lea 0x17d8(%rbp),%rdi 37: 48 rex.W 38: b8 00 00 00 00 mov $0x0,%eax 3d: 00 fc add %bh,%ah 3f: ff .byte 0xff