Oops: general protection fault, probably for non-canonical address 0xdffffc0000000083: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000418-0x000000000000041f]
CPU: 1 UID: 0 PID: 9400 Comm: syz.3.870 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:fib_lookup_good_nhc+0x85/0x3d0
Code: 4c 89 24 24 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 9b 7d 1a f8 41 bc 18 04 00 00 4c 03 23 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 e7 e8 7c 7d 1a f8 4d 8b 24 24 e8 23 fa
RSP: 0018:ffffc9000348f1d8 EFLAGS: 00010202
RAX: 0000000000000083 RBX: ffff88810fd6c420 RCX: 0000000000000002
RDX: ffff888109c03980 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88810fd6c437 R08: 0000000000000000 R09: ffffffff89e9c0d6
R10: ffffc9000348f4a0 R11: fffff52000691e9a R12: 0000000000000418
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff11021fad886
FS:  00007fb87d8ca6c0(0000) GS:ffff8881a3c14000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33f15ff8 CR3: 0000000024622000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 nexthop_get_nhc_lookup+0x1af/0x400
 fib_table_lookup+0xf26/0x16e0
 fib_lookup+0x1c5/0x440
 ip_route_output_key_hash_rcu+0x31b/0x23e0
 ip_route_output_key_hash+0x174/0x280
 ip_route_output_flow+0x2a/0x150
 rxrpc_assess_MTU_size+0x3c7/0xa90
 rxrpc_lookup_peer+0x576/0xa60
 rxrpc_do_sendmsg+0xb0a/0x1220
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x52d/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __sys_sendmmsg+0x227/0x430
 __x64_sys_sendmmsg+0xa0/0xc0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb87c98eba9
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:00007fb87d8ca038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007fb87cbd5fa0 RCX: 00007fb87c98eba9
RDX: 0000000000000001 RSI: 0000200000000300 RDI: 000000000000000b
RBP: 00007fb87ca11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb87cbd6038 R14: 00007fb87cbd5fa0 R15: 00007ffe7ce9bb38
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:fib_lookup_good_nhc+0x85/0x3d0
Code: 4c 89 24 24 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 9b 7d 1a f8 41 bc 18 04 00 00 4c 03 23 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 e7 e8 7c 7d 1a f8 4d 8b 24 24 e8 23 fa
RSP: 0018:ffffc9000348f1d8 EFLAGS: 00010202
RAX: 0000000000000083 RBX: ffff88810fd6c420 RCX: 0000000000000002
RDX: ffff888109c03980 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88810fd6c437 R08: 0000000000000000 R09: ffffffff89e9c0d6
R10: ffffc9000348f4a0 R11: fffff52000691e9a R12: 0000000000000418
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff11021fad886
FS:  00007fb87d8ca6c0(0000) GS:ffff8881a3c14000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33f12ff8 CR3: 0000000024622000 CR4: 00000000000006f0
