syzbot


general protection fault in ip6_pol_route

Status: premoderation: reported on 2026/03/12 19:09
Reported-by: syzbot+2bd4b55e76232c54b7a2@syzkaller.appspotmail.com
First crash: 10d, last: 10d
Similar bugs (7)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in ip6_pol_route (2) net 19 C done unreliable 9 1422d 1857d 0/29 auto-obsoleted due to no activity on 2022/09/19 15:39
android-6-12 general protection fault in ip6_pol_route 2 1 133d 133d 0/1 auto-obsoleted due to no activity on 2026/02/08 08:13
upstream general protection fault in ip6_pol_route (2) net 8 15 635d 642d 0/29 auto-obsoleted due to no activity on 2024/08/28 04:33
upstream general protection fault in ip6_pol_route net 8 73 643d 681d 26/29 fixed on 2024/06/18 11:11
upstream general protection fault in ip6_pol_route (3) net 8 syz error 25 285d 411d 0/29 auto-obsoleted due to no activity on 2025/09/19 08:31
linux-5.15 KASAN: use-after-free Read in ip6_pol_route 19 1 726d 726d 0/3 auto-obsoleted due to no activity on 2024/07/04 16:14
upstream Internal error in ip6_pol_route net 2 2 863d 886d 0/29 auto-obsoleted due to no activity on 2024/02/18 23:43

Sample crash report:
netlink: 12 bytes leftover after parsing attributes in process `syz.3.9248'.
general protection fault, probably for non-canonical address 0xdffffc000000000c: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000060-0x0000000000000067]
CPU: 0 PID: 29348 Comm: syz.3.9248 Tainted: G        W          syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:fib6_nh_get_excptn_bucket net/ipv6/route.c:1656 [inline]
RIP: 0010:rt6_find_cached_rt net/ipv6/route.c:1851 [inline]
RIP: 0010:ip6_pol_route+0x1d0/0x1130 net/ipv6/route.c:2266
Code: e8 55 8b ff ff 48 83 c4 08 49 83 c7 30 48 8b 9c 24 90 00 00 00 48 83 c3 60 48 89 d8 48 c1 e8 03 49 bc 00 00 00 00 00 fc ff df <42> 80 3c 20 00 74 08 48 89 df e8 41 62 59 fd 48 8b 03 48 83 e0 fe
RSP: 0018:ffffc900149d70c0 EFLAGS: 00010206
RAX: 000000000000000c RBX: 0000000000000060 RCX: dffffc0000000000
RDX: ffff88811dd2d100 RSI: 0000000000000002 RDI: 000000000000000a
RBP: ffffc900149d71f8 R08: ffff88811dd2d100 R09: 0000000000000002
R10: 000000000000000a R11: 0000000000000002 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888123068760 R15: ffffc900149d7710
FS:  00007f32749846c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2eb1bff8 CR3: 0000000149d71000 CR4: 00000000003506b0
Call Trace:
 <TASK>
 ip6_pol_route_output+0x51/0x80 net/ipv6/route.c:2634
 pol_lookup_func include/net/ip6_fib.h:589 [inline]
 fib6_rule_lookup+0x364/0x5f0 net/ipv6/fib6_rules.c:121
 ip6_route_output_flags_noref+0x283/0x340 net/ipv6/route.c:2666
 ip6_route_output_flags+0x3c/0x200 net/ipv6/route.c:2679
 ip6_dst_lookup_tail+0x1f2/0x14f0 net/ipv6/ip6_output.c:1152
 ip6_dst_lookup_flow+0x49/0xc0 net/ipv6/ip6_output.c:1255
 tcp_v6_connect+0x8ab/0x1590 net/ipv6/tcp_ipv6.c:287
 __inet_stream_connect+0x264/0xe70 net/ipv4/af_inet.c:675
 tcp_sendmsg_fastopen+0x3ac/0x600 net/ipv4/tcp.c:1205
 tcp_sendmsg_locked+0x386a/0x3de0 net/ipv4/tcp.c:1253
 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1488
 inet6_sendmsg+0xb6/0xd0 net/ipv6/af_inet6.c:673
 sock_sendmsg_nosec net/socket.c:716 [inline]
 __sock_sendmsg net/socket.c:728 [inline]
 __sys_sendto+0x4ac/0x660 net/socket.c:2142
 __do_sys_sendto net/socket.c:2154 [inline]
 __se_sys_sendto net/socket.c:2150 [inline]
 __x64_sys_sendto+0xe5/0x100 net/socket.c:2150
 x64_sys_call+0x83/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:45
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f3273b9c799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3274984028 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f3273e15fa0 RCX: 00007f3273b9c799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008
RBP: 00007f3273c32c99 R08: 00002000000001c0 R09: 000000000000001c
R10: 0000000020000050 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3273e16038 R14: 00007f3273e15fa0 R15: 00007ffe10abda78
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:fib6_nh_get_excptn_bucket net/ipv6/route.c:1656 [inline]
RIP: 0010:rt6_find_cached_rt net/ipv6/route.c:1851 [inline]
RIP: 0010:ip6_pol_route+0x1d0/0x1130 net/ipv6/route.c:2266
Code: e8 55 8b ff ff 48 83 c4 08 49 83 c7 30 48 8b 9c 24 90 00 00 00 48 83 c3 60 48 89 d8 48 c1 e8 03 49 bc 00 00 00 00 00 fc ff df <42> 80 3c 20 00 74 08 48 89 df e8 41 62 59 fd 48 8b 03 48 83 e0 fe
RSP: 0018:ffffc900149d70c0 EFLAGS: 00010206
RAX: 000000000000000c RBX: 0000000000000060 RCX: dffffc0000000000
RDX: ffff88811dd2d100 RSI: 0000000000000002 RDI: 000000000000000a
RBP: ffffc900149d71f8 R08: ffff88811dd2d100 R09: 0000000000000002
R10: 000000000000000a R11: 0000000000000002 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888123068760 R15: ffffc900149d7710
FS:  00007f32749846c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3273be9e80 CR3: 0000000149d71000 CR4: 00000000003506a0
----------------
Code disassembly (best guess):
   0:	e8 55 8b ff ff       	call   0xffff8b5a
   5:	48 83 c4 08          	add    $0x8,%rsp
   9:	49 83 c7 30          	add    $0x30,%r15
   d:	48 8b 9c 24 90 00 00 	mov    0x90(%rsp),%rbx
  14:	00
  15:	48 83 c3 60          	add    $0x60,%rbx
  19:	48 89 d8             	mov    %rbx,%rax
  1c:	48 c1 e8 03          	shr    $0x3,%rax
  20:	49 bc 00 00 00 00 00 	movabs $0xdffffc0000000000,%r12
  27:	fc ff df
* 2a:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	48 89 df             	mov    %rbx,%rdi
  34:	e8 41 62 59 fd       	call   0xfd59627a
  39:	48 8b 03             	mov    (%rbx),%rax
  3c:	48 83 e0 fe          	and    $0xfffffffffffffffe,%rax

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/12 19:08 android14-6.1 3c7447b2e379 4efadf07 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 general protection fault in ip6_pol_route
* Struck through repros no longer work on HEAD.