syzbot


general protection fault in __rt6_nh_dev_match

Status: auto-obsoleted due to no activity on 2025/08/22 18:12
Reported-by: syzbot+010380ede743b110f244@syzkaller.appspotmail.com
First crash: 103d, last: 91d

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc0000000020: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000100-0x0000000000000107]
CPU: 1 PID: 15881 Comm: syz.4.4395 Tainted: G        W         5.10.237-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:__rt6_device_match net/ipv6/route.c:473 [inline]
RIP: 0010:__rt6_nh_dev_match+0x121/0x220 net/ipv6/route.c:497
Code: 74 08 48 89 df e8 4f aa a9 fd 48 8b 1b 31 ff 44 89 fe e8 32 be 6f fd 45 85 ff 74 40 48 81 c3 00 01 00 00 48 89 d8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 ce 00 00 00 8b 1b 89 df 44 89 fe e8 d6
RSP: 0018:ffffc90000df7318 EFLAGS: 00010202
RAX: 0000000000000020 RBX: 0000000000000100 RCX: 0000000000000002
RDX: ffff888155d5a780 RSI: 000000000100fc03 RDI: 0000000000000000
RBP: ffffc90000df7358 R08: dffffc0000000000 R09: ffffc90000df74c0
R10: fffff520001bee9c R11: 1ffff920001bee98 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 000000000100fc03
FS:  00007f67e92bc6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000ffffffff CR3: 00000001184ff000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 nexthop_for_each_fib6_nh+0xf6/0x1e0 net/ipv4/nexthop.c:602
 rt6_nh_dev_match net/ipv6/route.c:517 [inline]
 rt6_device_match net/ipv6/route.c:546 [inline]
 ip6_pol_route_lookup+0x5bb/0x17d0 net/ipv6/route.c:1220
 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
 ip6_tnl_link_config+0x443/0x9c0 net/ipv6/ip6_tunnel.c:1507
 ip6_tnl_dev_init+0x46e/0x640 net/ipv6/ip6_tunnel.c:1937
 register_netdevice+0x351/0x13c0 net/core/dev.c:9986
 ip6_tnl_create2+0xc2/0x360 net/ipv6/ip6_tunnel.c:290
 ip6_tnl_create net/ipv6/ip6_tunnel.c:340 [inline]
 ip6_tnl_locate+0x60c/0x6f0 net/ipv6/ip6_tunnel.c:390
 ip6_tnl_ioctl+0x701/0xed0 net/ipv6/ip6_tunnel.c:1682
 dev_do_ioctl net/core/dev_ioctl.c:206 [inline]
 dev_ifsioc+0x69b/0xa50 net/core/dev_ioctl.c:312
 dev_ioctl+0x5ea/0xb80 net/core/dev_ioctl.c:506
 sock_ioctl+0x6a0/0x710 net/socket.c:1121
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0x121/0x1a0 fs/ioctl.c:739
 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:739
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f67eac53969
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:00007f67e92bc038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f67eae7afa0 RCX: 00007f67eac53969
RDX: 0000200000000340 RSI: 00000000000089f1 RDI: 0000000000000003
RBP: 00007f67eacd5ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f67eae7afa0 R15: 00007fff94ac34f8
Modules linked in:
---[ end trace 90103e26158f8ee4 ]---
RIP: 0010:__rt6_device_match net/ipv6/route.c:473 [inline]
RIP: 0010:__rt6_nh_dev_match+0x121/0x220 net/ipv6/route.c:497
Code: 74 08 48 89 df e8 4f aa a9 fd 48 8b 1b 31 ff 44 89 fe e8 32 be 6f fd 45 85 ff 74 40 48 81 c3 00 01 00 00 48 89 d8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 ce 00 00 00 8b 1b 89 df 44 89 fe e8 d6
RSP: 0018:ffffc90000df7318 EFLAGS: 00010202
RAX: 0000000000000020 RBX: 0000000000000100 RCX: 0000000000000002
RDX: ffff888155d5a780 RSI: 000000000100fc03 RDI: 0000000000000000
RBP: ffffc90000df7358 R08: dffffc0000000000 R09: ffffc90000df74c0
R10: fffff520001bee9c R11: 1ffff920001bee98 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 000000000100fc03
FS:  00007f67e92bc6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000ffffffff CR3: 00000001184ff000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	74 08                	je     0xa
   2:	48 89 df             	mov    %rbx,%rdi
   5:	e8 4f aa a9 fd       	call   0xfda9aa59
   a:	48 8b 1b             	mov    (%rbx),%rbx
   d:	31 ff                	xor    %edi,%edi
   f:	44 89 fe             	mov    %r15d,%esi
  12:	e8 32 be 6f fd       	call   0xfd6fbe49
  17:	45 85 ff             	test   %r15d,%r15d
  1a:	74 40                	je     0x5c
  1c:	48 81 c3 00 01 00 00 	add    $0x100,%rbx
  23:	48 89 d8             	mov    %rbx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 ce 00 00 00    	jne    0x105
  37:	8b 1b                	mov    (%rbx),%ebx
  39:	89 df                	mov    %ebx,%edi
  3b:	44 89 fe             	mov    %r15d,%esi
  3e:	e8                   	.byte 0xe8
  3f:	d6                   	(bad)

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/05/24 18:12 android13-5.10-lts 7e2543346ff7 ed351ea7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in __rt6_nh_dev_match
2025/05/13 02:33 android13-5.10-lts 7e2543346ff7 f6671af7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in __rt6_nh_dev_match
* Struck through repros no longer work on HEAD.