============================================ WARNING: possible recursive locking detected 6.8.0-syzkaller-05204-g237bb5f7f7f5 #0 Not tainted -------------------------------------------- syz-executor.0/7919 is trying to acquire lock: ffff88807e7c13e0 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff88807e7c13e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_ip6_multicast_query net/bridge/br_multicast.c:3523 [inline] ffff88807e7c13e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_ipv6_rcv net/bridge/br_multicast.c:3919 [inline] ffff88807e7c13e0 (&br->multicast_lock){+.-.}-{2:2}, at: br_multicast_rcv+0x30e2/0x8180 net/bridge/br_multicast.c:3974 but task is already holding lock: ffff888022f6d3e0 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff888022f6d3e0 (&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.0/7919: #0: ffffffff8e00d500 (console_lock){+.+.}-{0:0}, at: _printk+0xd5/0x120 kernel/printk/printk.c:2317 #1: ffffffff8e00d130 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:303 [inline] #1: ffffffff8e00d130 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:232 [inline] #1: ffffffff8e00d130 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:286 [inline] #1: ffffffff8e00d130 (console_srcu){....}-{0:0}, at: console_flush_all+0x14a/0xec0 kernel/printk/printk.c:2948 #2: ffffc90000a08c00 ((&pmctx->ip6_own_query.timer)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x600 kernel/time/timer.c:1789 #3: ffff888022f6d3e0 (&br->multicast_lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #3: ffff888022f6d3e0 (&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: 1 PID: 7919 Comm: syz-executor.0 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:console_flush_all+0x9cd/0xec0 kernel/printk/printk.c:2962 Code: 48 21 c3 0f 85 fa 01 00 00 e8 1f 6a 1f 00 48 8b 5c 24 38 4d 85 f6 75 07 e8 10 6a 1f 00 eb 06 e8 09 6a 1f 00 fb 48 8b 44 24 58 <42> 0f b6 04 28 84 c0 0f 85 4a 02 00 00 0f b6 1b 31 ff 89 de e8 ea RSP: 0018:ffffc90014336e20 EFLAGS: 00000287 RAX: 1ffff92002866e10 RBX: ffffc90014337080 RCX: 0000000000040000 RDX: ffffc90003aa1000 RSI: 0000000000002e80 RDI: 0000000000002e81 RBP: ffffc90014336fd0 R08: ffffffff8175863e R09: 1ffffffff2598ea0 R10: dffffc0000000000 R11: fffffbfff2598ea1 R12: ffffffff8e8f47a0 R13: dffffc0000000000 R14: 0000000000000200 R15: ffffffff8e8f47f8 console_unlock+0x13b/0x4d0 kernel/printk/printk.c:3025 vprintk_emit+0x509/0x720 kernel/printk/printk.c:2292 _printk+0xd5/0x120 kernel/printk/printk.c:2317 xt_ct_set_helper net/netfilter/xt_CT.c:82 [inline] xt_ct_tg_check+0xac9/0xdf0 net/netfilter/xt_CT.c:203 xt_ct_tg_check_v0+0x1e4/0x3f0 net/netfilter/xt_CT.c:250 xt_check_target+0x3b9/0xa40 net/netfilter/x_tables.c:1038 check_target net/ipv4/netfilter/ip_tables.c:510 [inline] find_check_entry net/ipv4/netfilter/ip_tables.c:552 [inline] translate_table+0x19b3/0x2260 net/ipv4/netfilter/ip_tables.c:716 do_replace net/ipv4/netfilter/ip_tables.c:1133 [inline] do_ipt_set_ctl+0x27d2/0x3dd0 net/ipv4/netfilter/ip_tables.c:1627 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: 0033:0x7f7c1d67dda9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7c1e4bd0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f7c1d7abf80 RCX: 00007f7c1d67dda9 RDX: 0000000000000040 RSI: 0004000000000000 RDI: 0000000000000006 RBP: 00007f7c1d6ca47a R08: 0000000000000278 R09: 0000000000000000 R10: 0000000020002700 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f7c1d7abf80 R15: 00007ffd489330d8 ---------------- Code disassembly (best guess): 0: 48 21 c3 and %rax,%rbx 3: 0f 85 fa 01 00 00 jne 0x203 9: e8 1f 6a 1f 00 call 0x1f6a2d e: 48 8b 5c 24 38 mov 0x38(%rsp),%rbx 13: 4d 85 f6 test %r14,%r14 16: 75 07 jne 0x1f 18: e8 10 6a 1f 00 call 0x1f6a2d 1d: eb 06 jmp 0x25 1f: e8 09 6a 1f 00 call 0x1f6a2d 24: fb sti 25: 48 8b 44 24 58 mov 0x58(%rsp),%rax * 2a: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax <-- trapping instruction 2f: 84 c0 test %al,%al 31: 0f 85 4a 02 00 00 jne 0x281 37: 0f b6 1b movzbl (%rbx),%ebx 3a: 31 ff xor %edi,%edi 3c: 89 de mov %ebx,%esi 3e: e8 .byte 0xe8 3f: ea (bad)