list_add corruption. prev->next should be next (ffffffff8a1dca60), but was ffff8881d884d030. (prev=ffff8881b7d3d8f0). ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:28! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 6063 Comm: syz-executor023 Not tainted 4.20.0-rc6-next-20181210+ #164 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__list_add_valid.cold.2+0x23/0x2a lib/list_debug.c:26 Code: e8 00 1f d2 fd 0f 0b 48 89 d9 48 c7 c7 20 e6 80 88 e8 ef 1e d2 fd 0f 0b 48 89 f1 48 c7 c7 a0 e6 80 88 48 89 de e8 db 1e d2 fd <0f> 0b 90 90 90 90 90 55 48 89 e5 41 57 41 56 49 be 00 00 00 00 00 RSP: 0018:ffff8881dad06ce0 EFLAGS: 00010286 RAX: 0000000000000075 RBX: ffffffff8a1dca60 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff816621c5 RDI: 0000000000000005 RBP: ffff8881dad06cf8 R08: ffff8881c0d08500 R09: ffffed103b5a5020 R10: ffffed103b5a5020 R11: ffff8881dad28107 R12: ffff8881b7b234b0 R13: ffff8881b7b23240 R14: ffffffff8a1dc820 R15: ffffffff8a1dcab0 FS: 0000000001f18940(0000) GS:ffff8881dad00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000006cf138 CR3: 00000001c147b000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __list_add include/linux/list.h:60 [inline] list_add_tail include/linux/list.h:93 [inline] neigh_alloc net/core/neighbour.c:395 [inline] ___neigh_create+0x14b7/0x2600 net/core/neighbour.c:553 __neigh_create+0x30/0x40 net/core/neighbour.c:640 ip6_finish_output2+0xa64/0x2940 net/ipv6/ip6_output.c:117 ip6_finish_output+0x58c/0xc60 net/ipv6/ip6_output.c:154 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip6_output+0x232/0x9d0 net/ipv6/ip6_output.c:171 dst_output include/net/dst.h:444 [inline] NF_HOOK include/linux/netfilter.h:289 [inline] ndisc_send_skb+0x1005/0x1560 net/ipv6/ndisc.c:491 ndisc_send_rs+0x134/0x6e0 net/ipv6/ndisc.c:685 addrconf_rs_timer+0x314/0x690 net/ipv6/addrconf.c:3840 call_timer_fn+0x272/0x920 kernel/time/timer.c:1325 expire_timers kernel/time/timer.c:1362 [inline] __run_timers+0x7e5/0xc70 kernel/time/timer.c:1681 run_timer_softirq+0x52/0xb0 kernel/time/timer.c:1694 __do_softirq+0x308/0xb7e kernel/softirq.c:292 cgroup: fork rejected by pids controller in /syz2 cgroup: fork rejected by pids controller in /syz0 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x17f/0x1c0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1cb/0x760 arch/x86/kernel/apic/apic.c:1061 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 RIP: 0010:lock_acquire+0x27a/0x520 kernel/locking/lockdep.c:3833 Code: 00 48 83 3d f7 2d 10 08 00 0f 84 c3 01 00 00 48 8b bd 20 ff ff ff 57 9d 0f 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 48 01 c3 <48> c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 45 d0 65 48 33 RSP: 0018:ffff8881b6557570 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: ffffed1036caaeb3 RCX: 0000000000000000 RDX: 1ffffffff12e4816 RSI: 0000000000000000 RDI: 0000000000000282 RBP: ffff8881b6557660 R08: ffff8881c0d08da0 R09: 0000000000000008 R10: 0000000000004ac7 R11: ffff8881c0d08500 R12: ffff8881c0d08500 R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000000 __might_fault+0x15e/0x1e0 mm/memory.c:4377 do_ip_getsockopt+0x1bb/0x2470 net/ipv4/ip_sockglue.c:1323 ip_getsockopt+0x9a/0x240 net/ipv4/ip_sockglue.c:1561 tcp_getsockopt+0x93/0xe0 net/ipv4/tcp.c:3591 sock_common_getsockopt+0x9a/0xe0 net/core/sock.c:2945 __sys_getsockopt+0x1ad/0x390 net/socket.c:1940 __do_sys_getsockopt net/socket.c:1951 [inline] __se_sys_getsockopt net/socket.c:1948 [inline] __x64_sys_getsockopt+0xbe/0x150 net/socket.c:1948 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x44638a Code: b8 10 01 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 0d d7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 ea d6 fb ff c3 66 0f 1f 84 00 00 00 00 00 RSP: 002b:00007ffdf02dfd18 EFLAGS: 00000246 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffda RBX: 00000000006d3ae0 RCX: 000000000044638a RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00000000006d3ae0 R08: 00007ffdf02dfd3c R09: 0000000000004000 R10: 00007ffdf02dfd40 R11: 0000000000000246 R12: 0000000000000003 R13: 00007ffdf02dfe40 R14: 00007ffdf02dfd40 R15: 0000000000000000 Modules linked in: ---[ end trace 11e0a909add8637c ]--- RIP: 0010:__list_add_valid.cold.2+0x23/0x2a lib/list_debug.c:26 Code: e8 00 1f d2 fd 0f 0b 48 89 d9 48 c7 c7 20 e6 80 88 e8 ef 1e d2 fd 0f 0b 48 89 f1 48 c7 c7 a0 e6 80 88 48 89 de e8 db 1e d2 fd <0f> 0b 90 90 90 90 90 55 48 89 e5 41 57 41 56 49 be 00 00 00 00 00 RSP: 0018:ffff8881dad06ce0 EFLAGS: 00010286 RAX: 0000000000000075 RBX: ffffffff8a1dca60 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff816621c5 RDI: 0000000000000005 RBP: ffff8881dad06cf8 R08: ffff8881c0d08500 R09: ffffed103b5a5020 R10: ffffed103b5a5020 R11: ffff8881dad28107 R12: ffff8881b7b234b0 cgroup: fork rejected by pids controller in /syz3 R13: ffff8881b7b23240 R14: ffffffff8a1dc820 R15: ffffffff8a1dcab0 FS: 0000000001f18940(0000) GS:ffff8881dad00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000006cf138 CR3: 00000001c147b000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 cgroup: fork rejected by pids controller in /syz1 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400