===================================== WARNING: bad unlock balance detected! 5.10.0-rc5-syzkaller #0 Not tainted ------------------------------------- syz-executor.2/20514 is trying to release lock (&____s->seqcount) at: [] NF_HOOK_COND include/linux/netfilter.h:290 [inline] [] ip6_output+0x79/0x2c0 net/ipv6/ip6_output.c:176 but there are no more locks to release! other info that might help us debug this: 3 locks held by syz-executor.2/20514: #0: ffffc90000cf4e90 ((&ndev->rs_timer)){+.-.}-{0:0}, at: call_timer_fn+0x0/0x340 kernel/time/timer.c:2026 #1: ffffffff85027c20 (rcu_read_lock){....}-{1:2}, at: rcu_read_unlock include/linux/rcupdate.h:691 [inline] #1: ffffffff85027c20 (rcu_read_lock){....}-{1:2}, at: ip6_nd_hdr net/ipv6/ndisc.c:453 [inline] #1: ffffffff85027c20 (rcu_read_lock){....}-{1:2}, at: ndisc_send_skb+0x19b/0x5f0 net/ipv6/ndisc.c:502 #2: ffffffff85027be0 (rcu_read_lock_bh){....}-{1:2}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline] #2: ffffffff85027be0 (rcu_read_lock_bh){....}-{1:2}, at: ip6_finish_output2+0x7d/0xa60 net/ipv6/ip6_output.c:103 stack backtrace: CPU: 1 PID: 20514 Comm: syz-executor.2 Not tainted 5.10.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x77/0x97 lib/dump_stack.c:118 __lock_release kernel/locking/lockdep.c:5121 [inline] lock_release+0x1dc/0x2d0 kernel/locking/lockdep.c:5457 seqcount_lockdep_reader_access include/linux/seqlock.h:104 [inline] read_seqbegin include/linux/seqlock.h:838 [inline] neigh_hh_output include/net/neighbour.h:469 [inline] neigh_output include/net/neighbour.h:508 [inline] ip6_finish_output2+0x544/0xa60 net/ipv6/ip6_output.c:117 NF_HOOK_COND include/linux/netfilter.h:290 [inline] ip6_output+0x79/0x2c0 net/ipv6/ip6_output.c:176 dst_output include/net/dst.h:443 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ndisc_send_skb+0x4b2/0x5f0 net/ipv6/ndisc.c:508 addrconf_rs_timer+0xd3/0x220 net/ipv6/addrconf.c:3873 call_timer_fn+0xa5/0x340 kernel/time/timer.c:1410 expire_timers kernel/time/timer.c:1455 [inline] __run_timers kernel/time/timer.c:1747 [inline] run_timer_softirq+0x259/0x680 kernel/time/timer.c:1760 __do_softirq+0xf0/0x5f1 kernel/softirq.c:298 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0x7c/0xa0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:393 [inline] __irq_exit_rcu kernel/softirq.c:423 [inline] irq_exit_rcu+0xc9/0xf0 kernel/softirq.c:435 sysvec_apic_timer_interrupt+0x57/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:631 RIP: 0010:__syscall_enter_from_user_work kernel/entry/common.c:79 [inline] RIP: 0010:syscall_enter_from_user_mode+0x26/0x50 kernel/entry/common.c:99 Code: cc cc cc cc 55 48 89 fd 53 48 8b 7c 24 10 48 89 f3 e8 5e f6 ff ff e8 39 2f 95 fd e8 f4 31 95 fd fb 65 48 8b 04 25 00 70 01 00 <48> 8b 30 f7 c6 c1 01 00 10 75 06 48 89 d8 5b 5d c3 48 89 ef 5b 5d RSP: 0018:ffffc90004b0bf30 EFLAGS: 00000206 RAX: ffff88811d35cbc0 RBX: 0000000000000003 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff84b0ffa9 RDI: ffffffff849b5b2e RBP: ffffc90004b0bf58 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 do_syscall_64+0xf/0x70 arch/x86/entry/common.c:41 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x417b71 Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 a4 1a 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007fff42a3e9b0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000417b71 RDX: 0000000000000000 RSI: 0000000000000081 RDI: 0000000000000004 RBP: 0000000000000000 R08: 00000000011a11e0 R09: 0000000000000000 R10: 00007fff42a3ea80 R11: 0000000000000293 R12: ffffffffffffffff R13: 0000000000000000 R14: 0000000000000003 R15: 000000000119bf8c