general protection fault, probably for non-canonical address 0xdffffc000000005b: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000002d8-0x00000000000002df]
CPU: 0 PID: 25741 Comm: syz.2.20328 Tainted: G W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2025
RIP: 0010:ip_ignore_linkdown include/linux/inetdevice.h:254 [inline]
RIP: 0010:fib_lookup_good_nhc net/ipv4/fib_trie.c:1363 [inline]
RIP: 0010:nexthop_get_nhc_lookup+0x1a2/0x6c0 include/net/nexthop.h:291
Code: 74 08 48 89 df e8 0e 6f bf fd 48 89 5d a8 48 8b 1b b8 d8 02 00 00 48 01 c3 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 df e8 e0 6e bf fd 48 8b 1b 48 85 db 74 68
RSP: 0018:ffffc90000006828 EFLAGS: 00010202
RAX: 000000000000005b RBX: 00000000000002d8 RCX: dffffc0000000000
RDX: ffff88811a5313c0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000006898 R08: ffff88811a5313c0 R09: 0000000000000003
R10: 0000000000000008 R11: 0000000080000702 R12: ffff88811d8e7100
R13: 0000000000000000 R14: 0000000000000000 R15: ffff88811925c510
FS: 00007fd7a2c2e6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffffd CR3: 000000010ca53000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
fib_table_lookup+0xe4c/0x1730 net/ipv4/fib_trie.c:1542
fib4_rule_action+0x115/0x1a0 net/ipv4/fib_rules.c:135
fib_rules_lookup+0x489/0x8d0 net/core/fib_rules.c:318
__fib_lookup+0xe4/0x150 net/ipv4/fib_rules.c:92
fib_lookup include/net/ip_fib.h:371 [inline]
__ip_rt_update_pmtu+0x456/0x790 net/ipv4/route.c:1073
ip_rt_update_pmtu+0x73f/0xa80 net/ipv4/route.c:1098
skb_dst_update_pmtu_no_confirm include/net/dst.h:548 [inline]
tnl_update_pmtu+0x39d/0xbc0 net/ipv4/ip_tunnel.c:505
ip_tunnel_xmit+0xecc/0x2280 net/ipv4/ip_tunnel.c:784
__gre_xmit net/ipv4/ip_gre.c:469 [inline]
ipgre_xmit+0x7c0/0xb30 net/ipv4/ip_gre.c:664
__netdev_start_xmit include/linux/netdevice.h:4864 [inline]
netdev_start_xmit include/linux/netdevice.h:4878 [inline]
xmit_one net/core/dev.c:3608 [inline]
dev_hard_start_xmit+0x244/0x670 net/core/dev.c:3624
__dev_queue_xmit+0x1446/0x2540 net/core/dev.c:4210
dev_queue_xmit+0x17/0x20 net/core/dev.c:4243
neigh_connected_output+0x432/0x460 net/core/neighbour.c:1538
neigh_output include/net/neighbour.h:517 [inline]
ip_finish_output2+0xad5/0xec0 net/ipv4/ip_output.c:237
__ip_finish_output+0x3fb/0x720 net/ipv4/ip_output.c:-1
ip_finish_output+0x33/0x1f0 net/ipv4/ip_output.c:325
NF_HOOK_COND include/linux/netfilter.h:288 [inline]
ip_mc_output+0x3fc/0x7f0 net/ipv4/ip_output.c:424
dst_output include/net/dst.h:451 [inline]
ip_local_out+0x96/0xb0 net/ipv4/ip_output.c:126
iptunnel_xmit+0x470/0x850 net/ipv4/ip_tunnel_core.c:82
udp_tunnel_xmit_skb+0x1ae/0x290 net/ipv4/udp_tunnel_core.c:190
tipc_udp_xmit+0x521/0x8e0 net/tipc/udp_media.c:192
tipc_udp_send_msg+0x246/0x2e0 net/tipc/udp_media.c:252
tipc_bearer_xmit_skb+0x27d/0x360 net/tipc/bearer.c:548
tipc_disc_timeout+0x6a2/0x830 net/tipc/discover.c:337
call_timer_fn+0x38/0x290 kernel/time/timer.c:1450
expire_timers kernel/time/timer.c:1495 [inline]
__run_timers+0x639/0x9a0 kernel/time/timer.c:1789
run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1802
__do_softirq+0x255/0x563 kernel/softirq.c:309
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+0x60/0x80 arch/x86/kernel/irq_64.c:77
invoke_softirq kernel/softirq.c:405 [inline]
__irq_exit_rcu+0x128/0x150 kernel/softirq.c:435
irq_exit_rcu+0x9/0x10 kernel/softirq.c:447
sysvec_apic_timer_interrupt+0xbf/0xe0 arch/x86/kernel/apic/apic.c:1106
asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:635
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x49/0x70 kernel/locking/spinlock.c:199
Code: 12 48 89 fb 48 c7 c7 f0 69 2c 86 e8 f1 9d 25 fd 48 89 df 48 83 3d 16 77 b4 01 00 74 27 e8 f3 1f d3 fc 66 90 fb bf 01 00 00 00 22 1f cc fc 65 8b 05 97 7a 8a 7b 85 c0 74 03 5b 5d c3 e8 d3 77
RSP: 0018:ffffc90000e673c8 EFLAGS: 00000246
RAX: 0000000000000001 RBX: dffffc0000000000 RCX: dffffc0000000000
RDX: 0000000040000002 RSI: 0000000000000000 RDI: 0000000000000001
RBP: ffffc90000e673d0 R08: dffffc0000000000 R09: fffffbfff0d46a1b
R10: fffffbfff0d46a1b R11: 1ffffffff0d46a1a R12: ffff8881f7055fc0
R13: ffff888120c83b6c R14: 0000000000000000 R15: ffff88811a5313c0
finish_lock_switch kernel/sched/core.c:3786 [inline]
finish_task_switch+0x12e/0x5a0 kernel/sched/core.c:3886
context_switch kernel/sched/core.c:4051 [inline]
__schedule+0xb4f/0x1310 kernel/sched/core.c:4806
preempt_schedule_common+0x9b/0xf0 kernel/sched/core.c:4965
preempt_schedule+0xa7/0xb0 kernel/sched/core.c:4990
preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:39
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
_raw_spin_unlock_irqrestore+0x74/0x80 kernel/locking/spinlock.c:191
spin_unlock_irqrestore include/linux/spinlock.h:409 [inline]
__wake_up_common_lock kernel/sched/wait.c:126 [inline]
__wake_up_sync_key+0x166/0x280 kernel/sched/wait.c:194
unix_dgram_recvmsg+0x498/0xd40 net/unix/af_unix.c:2180
____sys_recvmsg+0x291/0x580 net/socket.c:-1
___sys_recvmsg+0x1af/0x4f0 net/socket.c:2637
do_recvmmsg+0x347/0x790 net/socket.c:2731
__sys_recvmmsg net/socket.c:2810 [inline]
__do_sys_recvmmsg net/socket.c:2833 [inline]
__se_sys_recvmmsg net/socket.c:2826 [inline]
__x64_sys_recvmmsg+0x18d/0x240 net/socket.c:2826
do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fd7a41e6ba9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd7a2c2e038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fd7a442e090 RCX: 00007fd7a41e6ba9
RDX: 03fffffffffffcb5 RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007fd7a4269e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd7a442e128 R14: 00007fd7a442e090 R15: 00007fffd58d38f8
Modules linked in:
---[ end trace d8055b73cf881f72 ]---
RIP: 0010:ip_ignore_linkdown include/linux/inetdevice.h:254 [inline]
RIP: 0010:fib_lookup_good_nhc net/ipv4/fib_trie.c:1363 [inline]
RIP: 0010:nexthop_get_nhc_lookup+0x1a2/0x6c0 include/net/nexthop.h:291
Code: 74 08 48 89 df e8 0e 6f bf fd 48 89 5d a8 48 8b 1b b8 d8 02 00 00 48 01 c3 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 df e8 e0 6e bf fd 48 8b 1b 48 85 db 74 68
RSP: 0018:ffffc90000006828 EFLAGS: 00010202
RAX: 000000000000005b RBX: 00000000000002d8 RCX: dffffc0000000000
RDX: ffff88811a5313c0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000006898 R08: ffff88811a5313c0 R09: 0000000000000003
R10: 0000000000000008 R11: 0000000080000702 R12: ffff88811d8e7100
R13: 0000000000000000 R14: 0000000000000000 R15: ffff88811925c510
FS: 00007fd7a2c2e6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffffd CR3: 000000010ca53000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 74 08 je 0xa
2: 48 89 df mov %rbx,%rdi
5: e8 0e 6f bf fd call 0xfdbf6f18
a: 48 89 5d a8 mov %rbx,-0x58(%rbp)
e: 48 8b 1b mov (%rbx),%rbx
11: b8 d8 02 00 00 mov $0x2d8,%eax
16: 48 01 c3 add %rax,%rbx
19: 48 89 d8 mov %rbx,%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: 48 89 df mov %rbx,%rdi
33: e8 e0 6e bf fd call 0xfdbf6f18
38: 48 8b 1b mov (%rbx),%rbx
3b: 48 85 db test %rbx,%rbx
3e: 74 68 je 0xa8