syzbot


kernel BUG in fib6_add_rt2node

Status: closed as invalid on 2025/09/01 08:35
Subsystems: net
[Documentation on labels]
First crash: 111d, last: 65d

Sample crash report:
------------[ cut here ]------------
kernel BUG at net/ipv6/ip6_fib.c:1216!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 36 Comm: kworker/u8:2 Not tainted 6.16.0-syzkaller-11743-g6bcdbd62bd56 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:fib6_add_rt2node+0x3386/0x33a0 net/ipv6/ip6_fib.c:1216
Code: 08 8e f7 90 0f 0b 44 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c c4 fa ff ff 4c 89 ff e8 95 72 f1 f7 e9 b7 fa ff ff e8 9b 08 8e f7 90 <0f> 0b e8 93 08 8e f7 e9 98 fb ff ff 66 66 66 66 66 2e 0f 1f 84 00
RSP: 0018:ffffc90000ac7260 EFLAGS: 00010293
RAX: ffffffff8a31a315 RBX: ffff88807c98bc00 RCX: ffff88801d6b1e00
RDX: 0000000000000000 RSI: 00000000ffff0000 RDI: 0000000000000000
RBP: ffffc90000ac7450 R08: ffffc90000ac7510 R09: 1ffff11005318c05
R10: dffffc0000000000 R11: ffffed1005318c06 R12: ffff88807c98bc00
R13: ffff88807c98bc00 R14: 0000000000000000 R15: 00000000ffff0000
FS:  0000000000000000(0000) GS:ffff888125c24000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3b6b17af7a CR3: 0000000056d04000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 fib6_add+0x8da/0x18a0 net/ipv6/ip6_fib.c:1528
 __ip6_ins_rt net/ipv6/route.c:1351 [inline]
 ip6_ins_rt+0xc8/0x120 net/ipv6/route.c:1361
 __ipv6_ifa_notify+0x63f/0xac0 net/ipv6/addrconf.c:6283
 ipv6_ifa_notify net/ipv6/addrconf.c:6322 [inline]
 addrconf_dad_completed+0x180/0xd60 net/ipv6/addrconf.c:4320
 addrconf_dad_work+0xc36/0x14b0 net/ipv6/addrconf.c:-1
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:fib6_add_rt2node+0x3386/0x33a0 net/ipv6/ip6_fib.c:1216
Code: 08 8e f7 90 0f 0b 44 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c c4 fa ff ff 4c 89 ff e8 95 72 f1 f7 e9 b7 fa ff ff e8 9b 08 8e f7 90 <0f> 0b e8 93 08 8e f7 e9 98 fb ff ff 66 66 66 66 66 2e 0f 1f 84 00
RSP: 0018:ffffc90000ac7260 EFLAGS: 00010293
RAX: ffffffff8a31a315 RBX: ffff88807c98bc00 RCX: ffff88801d6b1e00
RDX: 0000000000000000 RSI: 00000000ffff0000 RDI: 0000000000000000
RBP: ffffc90000ac7450 R08: ffffc90000ac7510 R09: 1ffff11005318c05
R10: dffffc0000000000 R11: ffffed1005318c06 R12: ffff88807c98bc00
R13: ffff88807c98bc00 R14: 0000000000000000 R15: 00000000ffff0000
FS:  0000000000000000(0000) GS:ffff888125c24000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3b6b17af7a CR3: 0000000056d04000 CR4: 0000000000350ef0

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/06 05:13 upstream 6bcdbd62bd56 904e669c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root kernel BUG in fib6_add_rt2node
2025/07/30 08:05 upstream 86aa72182095 f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root kernel BUG in fib6_add_rt2node
2025/07/01 11:58 net 72fb83735c71 6e83b42d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce kernel BUG in fib6_add_rt2node
2025/06/21 17:09 net 714db279942b d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce kernel BUG in fib6_add_rt2node
* Struck through repros no longer work on HEAD.