list_add corruption. prev->next should be next (ffffffff8a1dca60), but was ffff8881ba81c270. (prev=ffff8881cdf1a2b0). ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:28! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 20552 Comm: syz-executor0 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:ffff8881dac06ce0 EFLAGS: 00010286 RAX: 0000000000000075 RBX: ffffffff8a1dca60 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff816621c5 RDI: 0000000000000005 RBP: ffff8881dac06cf8 R08: ffff8881c08be580 R09: ffffed103b585020 R10: ffffed103b585020 R11: ffff8881dac28107 R12: ffff888191142bb0 R13: ffff888191142940 R14: ffffffff8a1dc820 R15: ffffffff8a1dcab0 FS: 00007fb80bbaa700(0000) GS:ffff8881dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020600000 CR3: 00000001be1f2000 CR4: 00000000001406f0 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 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:arch_local_irq_restore arch/x86/include/asm/paravirt.h:766 [inline] RIP: 0010:lock_release+0x51d/0xa00 kernel/locking/lockdep.c:3866 Code: 00 00 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 55 03 00 00 48 83 3d 42 35 10 08 00 0f 84 15 02 00 00 48 8b bd e0 fe 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 RSP: 0018:ffff8881b48f7858 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: 1ffff1103691ef10 RCX: 1ffff11038117dbe RDX: 1ffffffff12e4816 RSI: 1ffff11038117dc5 RDI: 0000000000000282 RBP: ffff8881b48f7988 R08: 1ffff1103691ef14 R09: 0000000000000008 R10: 0000000000000002 R11: ffff8881c08be580 R12: ffff8881c08be580 R13: 0000000000000001 R14: ffff8881c08be580 R15: ffff8881b48f78a0 __might_fault+0x19e/0x1e0 mm/memory.c:4377 _copy_from_user+0x30/0x150 lib/usercopy.c:10 copy_from_user include/linux/uaccess.h:147 [inline] input_event_from_user+0x13c/0x4e0 drivers/input/input-compat.c:34 evdev_write+0x364/0x870 drivers/input/evdev.c:559 __vfs_write+0x119/0xab0 fs/read_write.c:485 vfs_write+0x1fc/0x580 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457679 Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fb80bba9c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457679 RDX: 00000000fffffe82 RSI: 000000002004d000 RDI: 0000000000000004 RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb80bbaa6d4 R13: 00000000004c6126 R14: 00000000004dacd8 R15: 00000000ffffffff Modules linked in: ---[ end trace 440a6d8d8202ffc7 ]--- 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:ffff8881dac06ce0 EFLAGS: 00010286 RAX: 0000000000000075 RBX: ffffffff8a1dca60 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff816621c5 RDI: 0000000000000005 RBP: ffff8881dac06cf8 R08: ffff8881c08be580 R09: ffffed103b585020 R10: ffffed103b585020 R11: ffff8881dac28107 R12: ffff888191142bb0 R13: ffff888191142940 R14: ffffffff8a1dc820 R15: ffffffff8a1dcab0 FS: 00007fb80bbaa700(0000) GS:ffff8881dac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020600000 CR3: 00000001be1f2000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400