netdevsim netdevsim3 eth0: set [1, 0] type 2 family 0 port 6081 - 0
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000083: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000418-0x000000000000041f]
CPU: 0 UID: 0 PID: 10233 Comm: kworker/u8:12 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: krdsd rds_connect_worker
RIP: 0010:ip_ignore_linkdown include/linux/inetdevice.h:270 [inline]
RIP: 0010:fib_lookup_good_nhc+0x85/0x3d0 net/ipv4/fib_trie.c:1408
Code: 4c 89 24 24 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 5b 7f 19 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 3c 7f 19 f8 4d 8b 24 24 e8 93 60
RSP: 0018:ffffc9001cec6eb0 EFLAGS: 00010202
RAX: 0000000000000083 RBX: ffff888039a65820 RCX: 0000000000000000
RDX: ffff88802415da00 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888039a65837 R08: 0000000000000000 R09: ffffffff8a0fa7ff
R10: 0000000000000008 R11: 0000000000000000 R12: 0000000000000418
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff1100734cb06
FS:  0000000000000000(0000) GS:ffff888125c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9a97748e9c CR3: 000000002935a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 nexthop_get_nhc_lookup+0x1af/0x400 include/net/nexthop.h:437
 fib_table_lookup+0xf26/0x16e0 net/ipv4/fib_trie.c:1584
 fib4_rule_action+0x1fb/0x330 net/ipv4/fib_rules.c:139
 fib_rules_lookup+0x8a6/0xe90 net/core/fib_rules.c:339
 __fib_lookup+0xf9/0x200 net/ipv4/fib_rules.c:96
 ip_route_output_key_hash_rcu+0x31b/0x23e0 net/ipv4/route.c:2809
 ip_route_output_key_hash+0x174/0x280 net/ipv4/route.c:2700
 __ip_route_output_key include/net/route.h:169 [inline]
 ip_route_output_flow+0x2a/0x150 net/ipv4/route.c:2927
 ip_route_connect include/net/route.h:355 [inline]
 tcp_v4_connect+0x846/0x1a00 net/ipv4/tcp_ipv4.c:256
 __inet_stream_connect+0x2ab/0xe80 net/ipv4/af_inet.c:679
 inet_stream_connect+0x66/0xa0 net/ipv4/af_inet.c:750
 kernel_connect+0x116/0x180 net/socket.c:3656
 rds_tcp_conn_path_connect+0x512/0x680 net/rds/tcp_connect.c:176
 rds_connect_worker+0x1d8/0x290 net/rds/threads.c:176
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ip_ignore_linkdown include/linux/inetdevice.h:270 [inline]
RIP: 0010:fib_lookup_good_nhc+0x85/0x3d0 net/ipv4/fib_trie.c:1408
Code: 4c 89 24 24 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 5b 7f 19 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 3c 7f 19 f8 4d 8b 24 24 e8 93 60
RSP: 0018:ffffc9001cec6eb0 EFLAGS: 00010202
RAX: 0000000000000083 RBX: ffff888039a65820 RCX: 0000000000000000
RDX: ffff88802415da00 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888039a65837 R08: 0000000000000000 R09: ffffffff8a0fa7ff
R10: 0000000000000008 R11: 0000000000000000 R12: 0000000000000418
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff1100734cb06
FS:  0000000000000000(0000) GS:ffff888125c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555914d05c8 CR3: 000000002821e000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	4c 89 24 24          	mov    %r12,(%rsp)
   4:	48 89 d8             	mov    %rbx,%rax
   7:	48 c1 e8 03          	shr    $0x3,%rax
   b:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1)
  10:	74 08                	je     0x1a
  12:	48 89 df             	mov    %rbx,%rdi
  15:	e8 5b 7f 19 f8       	call   0xf8197f75
  1a:	41 bc 18 04 00 00    	mov    $0x418,%r12d
  20:	4c 03 23             	add    (%rbx),%r12
  23:	4c 89 e0             	mov    %r12,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	4c 89 e7             	mov    %r12,%rdi
  34:	e8 3c 7f 19 f8       	call   0xf8197f75
  39:	4d 8b 24 24          	mov    (%r12),%r12
  3d:	e8                   	.byte 0xe8
  3e:	93                   	xchg   %eax,%ebx
  3f:	60                   	(bad)