syzbot

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: 27442 Comm: syz.2.9981 Tainted: G        W         5.10.240-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__in6_dev_get include/net/addrconf.h:355 [inline]
RIP: 0010:ip6_ignore_linkdown include/net/addrconf.h:446 [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 13 96 a6 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 eb 95 a6 fd 4d 8b 24 24 4d 85 e4 0f
RSP: 0018:ffffc90000170070 EFLAGS: 00010206
RAX: 000000000000005c RBX: 0000000000000003 RCX: dffffc0000000000
RDX: ffff888153434f00 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900001700f8 R08: ffffc90000170420 R09: ffffc90000170430
R10: fffff5200002e0a6 R11: 1ffff9200002e0a2 R12: 00000000000002e0
R13: 1ffff1102a9b5b04 R14: ffff888154dad820 R15: 0000000000000000
FS:  00007f30ab6456c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffffd CR3: 000000013e160000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 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_lookup+0x2ef/0x560 net/ipv6/fib6_rules.c:120
 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_flow+0x49/0xc0 net/ipv6/ip6_output.c:1220
 tipc_udp_xmit+0x305/0x8e0 net/tipc/udp_media.c:204
 tipc_udp_send_msg+0x20c/0x2e0 net/tipc/udp_media.c:265
 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
 </IRQ>
 __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:scm_recv+0xd/0x540 include/net/scm.h:125
Code: c1 03 38 c1 7c 81 48 89 df e8 ef e3 ad fd e9 74 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 53 <48> 83 e4 e0 48 81 ec c0 00 00 00 48 89 d3 49 89 f4 49 89 ff 65 48
RSP: 0018:ffffc90002dc7748 EFLAGS: 00000246
RAX: ffffffff83efe4fd RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc90002dc7820 RSI: ffffc90002dc7d60 RDI: ffff88813578c000
RBP: ffffc90002dc7770 R08: dffffc0000000000 R09: ffffed1023ffb46d
R10: ffffed1023ffb46d R11: 1ffff11023ffb46c R12: dffffc0000000000
R13: ffffc90002dc7d60 R14: ffff888140c3bc80 R15: 0000000000000000
 unix_dgram_recvmsg+0x9b3/0xd40 net/unix/af_unix.c:2230
 ____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: 0033:0x7f30acbfdbe9
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:00007f30ab645038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f30ace25090 RCX: 00007f30acbfdbe9
RDX: 000000000400034f RSI: 0000200000000480 RDI: 0000000000000003
RBP: 00007f30acc80e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f30ace25128 R14: 00007f30ace25090 R15: 00007ffe80c37048
Modules linked in:
---[ end trace 87b5558d999d708c ]---
RIP: 0010:__in6_dev_get include/net/addrconf.h:355 [inline]
RIP: 0010:ip6_ignore_linkdown include/net/addrconf.h:446 [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 13 96 a6 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 eb 95 a6 fd 4d 8b 24 24 4d 85 e4 0f
RSP: 0018:ffffc90000170070 EFLAGS: 00010206
RAX: 000000000000005c RBX: 0000000000000003 RCX: dffffc0000000000
RDX: ffff888153434f00 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900001700f8 R08: ffffc90000170420 R09: ffffc90000170430
R10: fffff5200002e0a6 R11: 1ffff9200002e0a2 R12: 00000000000002e0
R13: 1ffff1102a9b5b04 R14: ffff888154dad820 R15: 0000000000000000
FS:  00007f30ab6456c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffffd CR3: 000000013e160000 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 13 96 a6 fd       	call   0xfda69623
  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 eb 95 a6 fd       	call   0xfda69623
  38:	4d 8b 24 24          	mov    (%r12),%r12
  3c:	4d 85 e4             	test   %r12,%r12
  3f:	0f                   	.byte 0xf