general protection fault in ip6_create_rt

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
android-5-10	general protection fault in ip6_create_rt_rcu	2				1	148d	148d	0/2	auto-obsoleted due to no activity on 2025/08/11 02:40
upstream	general protection fault in ip6_create_rt_rcu net	2				2	154d	159d	0/29	auto-obsoleted due to no activity on 2025/08/14 23:11
general protection fault, probably for non-canonical address 0xdffffc000000009f: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000004f8-0x00000000000004ff]
CPU: 1 PID: 7035 Comm: syz.9.14761 Tainted: G        W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:read_pnet include/net/net_namespace.h:335 [inline]
RIP: 0010:dev_net include/linux/netdevice.h:2396 [inline]
RIP: 0010:ip6_create_rt_rcu+0x1e2/0x520 net/ipv6/route.c:1185
Code: b6 04 28 84 c0 0f 85 31 03 00 00 41 0f b6 06 89 c1 83 e1 02 83 e0 04 44 8d 34 88 49 8d bc 24 f8 04 00 00 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 05 e8 22 76 a6 fd 4d 8b ac 24 f8 04 00 00 49 8d
RSP: 0018:ffffc900013370e0 EFLAGS: 00010206
RAX: 000000000000009f RBX: ffffc90001337200 RCX: 0000000000000000
RDX: ffff8881143293c0 RSI: 0000000000000001 RDI: 00000000000004f8
RBP: ffffc90001337190 R08: 0000000000000004 R09: 0000000000000003
R10: fffff52000266e24 R11: 1ffff92000266e24 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff88811339c22c
FS:  00007f83b80aa6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f83afd09000 CR3: 0000000114b10000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ip6_pol_route_lookup+0x145d/0x17d0 net/ipv6/route.c:1245
 pol_lookup_func include/net/ip6_fib.h:594 [inline]
 fib6_rule_lookup+0x2ef/0x560 net/ipv6/fib6_rules.c:120
 rt6_lookup+0x116/0x1d0 net/ipv6/route.c:1279
 __ipv6_sock_mc_join+0x43e/0x5c0 net/ipv6/mcast.c:167
 ipv6_sock_mc_join+0x27/0x30 net/ipv6/mcast.c:204
 ipv6_mcast_join_leave+0x174/0x1f0 net/ipv6/ipv6_sockglue.c:293
 do_ipv6_setsockopt net/ipv6/ipv6_sockglue.c:880 [inline]
 ipv6_setsockopt+0x8ad/0x3860 net/ipv6/ipv6_sockglue.c:1009
 udpv6_setsockopt+0x92/0xb0 net/ipv6/udp.c:1658
 sock_common_setsockopt+0xa0/0xb0 net/core/sock.c:3318
 __sys_setsockopt+0x2ed/0x460 net/socket.c:2146
 __do_sys_setsockopt net/socket.c:2157 [inline]
 __se_sys_setsockopt net/socket.c:2154 [inline]
 __x64_sys_setsockopt+0xbf/0xd0 net/socket.c:2154
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f83b9683ec9
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:00007f83b80aa038 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f83b98db180 RCX: 00007f83b9683ec9
RDX: 000000000000002a RSI: 0000000000000029 RDI: 0000000000000007
RBP: 00007f83b9706f91 R08: 0000000000000088 R09: 0000000000000000
R10: 0000200000000140 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f83b98db218 R14: 00007f83b98db180 R15: 00007ffe9af622b8
Modules linked in:
---[ end trace 5c414dc257a1e91b ]---
RIP: 0010:read_pnet include/net/net_namespace.h:335 [inline]
RIP: 0010:dev_net include/linux/netdevice.h:2396 [inline]
RIP: 0010:ip6_create_rt_rcu+0x1e2/0x520 net/ipv6/route.c:1185
Code: b6 04 28 84 c0 0f 85 31 03 00 00 41 0f b6 06 89 c1 83 e1 02 83 e0 04 44 8d 34 88 49 8d bc 24 f8 04 00 00 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 05 e8 22 76 a6 fd 4d 8b ac 24 f8 04 00 00 49 8d
RSP: 0018:ffffc900013370e0 EFLAGS: 00010206
RAX: 000000000000009f RBX: ffffc90001337200 RCX: 0000000000000000
RDX: ffff8881143293c0 RSI: 0000000000000001 RDI: 00000000000004f8
RBP: ffffc90001337190 R08: 0000000000000004 R09: 0000000000000003
R10: fffff52000266e24 R11: 1ffff92000266e24 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff88811339c22c
FS:  00007f83b80aa6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f83afd09000 CR3: 0000000114b10000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	b6 04                	mov    $0x4,%dh
   2:	28 84 c0 0f 85 31 03 	sub    %al,0x331850f(%rax,%rax,8)
   9:	00 00                	add    %al,(%rax)
   b:	41 0f b6 06          	movzbl (%r14),%eax
   f:	89 c1                	mov    %eax,%ecx
  11:	83 e1 02             	and    $0x2,%ecx
  14:	83 e0 04             	and    $0x4,%eax
  17:	44 8d 34 88          	lea    (%rax,%rcx,4),%r14d
  1b:	49 8d bc 24 f8 04 00 	lea    0x4f8(%r12),%rdi
  22:	00
  23:	48 89 f8             	mov    %rdi,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1) <-- trapping instruction
  2f:	74 05                	je     0x36
  31:	e8 22 76 a6 fd       	call   0xfda67658
  36:	4d 8b ac 24 f8 04 00 	mov    0x4f8(%r12),%r13
  3d:	00
  3e:	49                   	rex.WB
  3f:	8d                   	.byte 0x8d