syzbot


general protection fault in ip6_create_rt_rcu

Status: upstream: reported on 2025/05/01 14:38
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+3182876310f7cd8e31ec@syzkaller.appspotmail.com
First crash: 17d, last: 10d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [net?] general protection fault in ip6_create_rt_rcu 0 (1) 2025/05/01 14:38
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-10 general protection fault in ip6_create_rt_rcu 1 4d04h 4d04h 0/2 premoderation: reported on 2025/05/13 02:39

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000021: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000108-0x000000000000010f]
CPU: 1 UID: 0 PID: 9778 Comm: syz.3.1134 Not tainted 6.15.0-rc5-syzkaller-00032-g0d8d44db295c #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
RIP: 0010:read_pnet include/net/net_namespace.h:409 [inline]
RIP: 0010:dev_net include/linux/netdevice.h:2708 [inline]
RIP: 0010:ip6_create_rt_rcu+0x272/0x590 net/ipv6/route.c:1236
Code: 34 a0 9e f7 45 0f b7 e4 e8 cb 33 50 01 49 8d 87 08 01 00 00 48 89 c2 48 89 44 24 08 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 d6 02 00 00 49 8b 87 08 01 00 00 44 89 e1 ba ff
RSP: 0018:ffffc9000b6e7580 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffff888036310a2c RCX: ffffc9000c872000
RDX: 0000000000000021 RSI: ffffffff8a1c92bc RDI: 0000000000000001
RBP: ffffc9000b6e76e0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 1ffff920016dceb2 R14: ffff888036310a00 R15: 0000000000000000
FS:  00007f8bcbf526c0(0000) GS:ffff888124adf000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555761f8608 CR3: 000000005dd74000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ip6_pol_route_lookup+0xbfb/0x1e10 net/ipv6/route.c:1293
 pol_lookup_func include/net/ip6_fib.h:616 [inline]
 fib6_rule_lookup+0x5e8/0x720 net/ipv6/fib6_rules.c:125
 rt6_lookup+0x16b/0x220 net/ipv6/route.c:1327
 ipv6_sock_ac_join+0x643/0x800 net/ipv6/anycast.c:96
 do_ipv6_setsockopt+0x3684/0x4420 net/ipv6/ipv6_sockglue.c:919
 ipv6_setsockopt+0xcb/0x170 net/ipv6/ipv6_sockglue.c:993
 tcp_setsockopt+0xa4/0x100 net/ipv4/tcp.c:4077
 do_sock_setsockopt+0x221/0x470 net/socket.c:2296
 __sys_setsockopt+0x1a0/0x230 net/socket.c:2321
 __do_sys_setsockopt net/socket.c:2327 [inline]
 __se_sys_setsockopt net/socket.c:2324 [inline]
 __x64_sys_setsockopt+0xbd/0x160 net/socket.c:2324
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8bcb18e969
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:00007f8bcbf52038 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f8bcb3b5fa0 RCX: 00007f8bcb18e969
RDX: 000000000000001b RSI: 0000000000000029 RDI: 0000000000000005
RBP: 00007f8bcb210ab1 R08: 0000000000000014 R09: 0000000000000000
R10: 00002000000000c0 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f8bcb3b5fa0 R15: 00007fff50ae4558
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:read_pnet include/net/net_namespace.h:409 [inline]
RIP: 0010:dev_net include/linux/netdevice.h:2708 [inline]
RIP: 0010:ip6_create_rt_rcu+0x272/0x590 net/ipv6/route.c:1236
Code: 34 a0 9e f7 45 0f b7 e4 e8 cb 33 50 01 49 8d 87 08 01 00 00 48 89 c2 48 89 44 24 08 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 d6 02 00 00 49 8b 87 08 01 00 00 44 89 e1 ba ff
RSP: 0018:ffffc9000b6e7580 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffff888036310a2c RCX: ffffc9000c872000
RDX: 0000000000000021 RSI: ffffffff8a1c92bc RDI: 0000000000000001
RBP: ffffc9000b6e76e0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 1ffff920016dceb2 R14: ffff888036310a00 R15: 0000000000000000
FS:  00007f8bcbf526c0(0000) GS:ffff888124adf000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2ef0fff8 CR3: 000000005dd74000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	34 a0                	xor    $0xa0,%al
   2:	9e                   	sahf
   3:	f7 45 0f b7 e4 e8 cb 	testl  $0xcbe8e4b7,0xf(%rbp)
   a:	33 50 01             	xor    0x1(%rax),%edx
   d:	49 8d 87 08 01 00 00 	lea    0x108(%r15),%rax
  14:	48 89 c2             	mov    %rax,%rdx
  17:	48 89 44 24 08       	mov    %rax,0x8(%rsp)
  1c:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  23:	fc ff df
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	0f 85 d6 02 00 00    	jne    0x30a
  34:	49 8b 87 08 01 00 00 	mov    0x108(%r15),%rax
  3b:	44 89 e1             	mov    %r12d,%ecx
  3e:	ba                   	.byte 0xba
  3f:	ff                   	.byte 0xff

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/05/06 23:10 upstream 0d8d44db295c 350f4ffc .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root general protection fault in ip6_create_rt_rcu
2025/04/30 02:12 upstream 8bac8898fe39 aeb6ec69 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root general protection fault in ip6_create_rt_rcu
* Struck through repros no longer work on HEAD.