general protection fault, probably for non-canonical address 0xdffffc000000005c: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x00000000000002e0-0x00000000000002e7] CPU: 1 PID: 16720 Comm: syz.0.4777 Tainted: G W 5.10.237-syzkaller-00309-g7e2543346ff7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:__in6_dev_get include/net/addrconf.h:343 [inline] RIP: 0010:ip6_ignore_linkdown include/net/addrconf.h:434 [inline] RIP: 0010:find_match+0xa7/0xd60 net/ipv6/route.c:739 Code: 41 80 7c 05 00 00 74 08 4c 89 f7 e8 63 8c a9 fd 41 bc e0 02 00 00 4d 03 26 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 e7 e8 3b 8c a9 fd 4d 8b 24 24 4d 85 e4 0f RSP: 0018:ffffc90000e8e710 EFLAGS: 00010206 RAX: 000000000000005c RBX: 0000000000000002 RCX: dffffc0000000000 RDX: ffff88811c98cf00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000e8e798 R08: ffffc90000e8eac0 R09: ffffc90000e8ead0 R10: fffff520001d1d7a R11: 1ffff920001d1d76 R12: 00000000000002e0 R13: 1ffff11022e38fa4 R14: ffff8881171c7d20 R15: 0000000000000000 FS: 00007f0e24a2e6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3081fffc CR3: 000000012299a000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rt6_nh_find_match+0xd9/0x140 net/ipv6/route.c:779 nexthop_for_each_fib6_nh+0xf6/0x1e0 net/ipv4/nexthop.c:602 __find_rr_leaf+0x50f/0x900 net/ipv6/route.c:820 find_rr_leaf net/ipv6/route.c:848 [inline] rt6_select net/ipv6/route.c:892 [inline] fib6_table_lookup+0x2f4/0x9f0 net/ipv6/route.c:2190 ip6_pol_route+0x145/0x1110 net/ipv6/route.c:2226 ip6_pol_route_output+0x51/0x80 net/ipv6/route.c:2475 pol_lookup_func include/net/ip6_fib.h:594 [inline] __fib6_rule_action net/ipv6/fib6_rules.c:232 [inline] fib6_rule_action+0x1c7/0x710 net/ipv6/fib6_rules.c:270 fib_rules_lookup+0x489/0x8d0 net/core/fib_rules.c:318 fib6_rule_lookup+0x179/0x560 net/ipv6/fib6_rules.c:107 ip6_route_output_flags_noref+0x248/0x2f0 net/ipv6/route.c:2507 ip6_route_output_flags+0x3c/0x200 net/ipv6/route.c:2520 ip6_dst_lookup_tail+0x1b9/0x1210 net/ipv6/ip6_output.c:1117 ip6_dst_lookup+0x53/0x60 net/ipv6/ip6_output.c:1198 icmpv6_echo_reply+0x88f/0x1120 net/ipv6/icmp.c:774 icmpv6_rcv+0x10ff/0x16c0 net/ipv6/icmp.c:915 ip6_protocol_deliver_rcu+0xa77/0x1340 net/ipv6/ip6_input.c:427 ip6_input_finish net/ipv6/ip6_input.c:468 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip6_input+0xd6/0x1f0 net/ipv6/ip6_input.c:477 dst_input include/net/dst.h:461 [inline] ip6_rcv_finish+0x18c/0x360 net/ipv6/ip6_input.c:80 NF_HOOK include/linux/netfilter.h:299 [inline] ipv6_rcv+0xec/0x210 net/ipv6/ip6_input.c:301 __netif_receive_skb_one_core net/core/dev.c:5402 [inline] __netif_receive_skb+0xc8/0x280 net/core/dev.c:5516 netif_receive_skb_internal net/core/dev.c:5621 [inline] netif_receive_skb+0x9b/0x3d0 net/core/dev.c:5680 tun_rx_batched+0x5e8/0x710 drivers/net/tun.c:-1 tun_get_user+0x25d0/0x3090 drivers/net/tun.c:2026 tun_chr_write_iter+0x1bf/0x270 drivers/net/tun.c:2059 call_write_iter include/linux/fs.h:2058 [inline] new_sync_write fs/read_write.c:518 [inline] vfs_write+0x725/0xd60 fs/read_write.c:605 ksys_write+0x140/0x240 fs/read_write.c:658 __do_sys_write fs/read_write.c:670 [inline] __se_sys_write fs/read_write.c:667 [inline] __x64_sys_write+0x7b/0x90 fs/read_write.c:667 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f0e263c441f Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48 RSP: 002b:00007f0e24a2e000 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f0e265ecfa0 RCX: 00007f0e263c441f RDX: 000000000000003e RSI: 00002000000004c0 RDI: 00000000000000c8 RBP: 00007f0e26447ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000003e R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f0e265ecfa0 R15: 00007ffeca4fd878 Modules linked in: ---[ end trace 987a88fecb3fb531 ]--- RIP: 0010:__in6_dev_get include/net/addrconf.h:343 [inline] RIP: 0010:ip6_ignore_linkdown include/net/addrconf.h:434 [inline] RIP: 0010:find_match+0xa7/0xd60 net/ipv6/route.c:739 Code: 41 80 7c 05 00 00 74 08 4c 89 f7 e8 63 8c a9 fd 41 bc e0 02 00 00 4d 03 26 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 e7 e8 3b 8c a9 fd 4d 8b 24 24 4d 85 e4 0f RSP: 0018:ffffc90000e8e710 EFLAGS: 00010206 RAX: 000000000000005c RBX: 0000000000000002 RCX: dffffc0000000000 RDX: ffff88811c98cf00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000e8e798 R08: ffffc90000e8eac0 R09: ffffc90000e8ead0 R10: fffff520001d1d7a R11: 1ffff920001d1d76 R12: 00000000000002e0 R13: 1ffff11022e38fa4 R14: ffff8881171c7d20 R15: 0000000000000000 FS: 00007f0e24a2e6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3081fffc CR3: 000000012299a000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 41 80 7c 05 00 00 cmpb $0x0,0x0(%r13,%rax,1) 6: 74 08 je 0x10 8: 4c 89 f7 mov %r14,%rdi b: e8 63 8c a9 fd call 0xfda98c73 10: 41 bc e0 02 00 00 mov $0x2e0,%r12d 16: 4d 03 26 add (%r14),%r12 19: 4c 89 e0 mov %r12,%rax 1c: 48 c1 e8 03 shr $0x3,%rax 20: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx 27: fc ff df * 2a: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) <-- trapping instruction 2e: 74 08 je 0x38 30: 4c 89 e7 mov %r12,%rdi 33: e8 3b 8c a9 fd call 0xfda98c73 38: 4d 8b 24 24 mov (%r12),%r12 3c: 4d 85 e4 test %r12,%r12 3f: 0f .byte 0xf