syzbot


general protection fault in ip6_ins_rt

Status: upstream: reported on 2025/05/19 10:23
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+ce95bbc882771b5d81f7@syzkaller.appspotmail.com
First crash: 7d19h, last: 7d19h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [net?] general protection fault in ip6_ins_rt 0 (1) 2025/05/19 10:23

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037]
CPU: 0 UID: 0 PID: 1136 Comm: kworker/u32:5 Not tainted 6.15.0-rc6-syzkaller-00085-gc94d59a126cb #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:kasan_byte_accessible+0x15/0x30 mm/kasan/generic.c:199
Code: 00 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 48 b8 00 00 00 00 00 fc ff df 48 c1 ef 03 48 01 c7 <0f> b6 07 3c 07 0f 96 c0 e9 0e 29 4d 09 66 66 2e 0f 1f 84 00 00 00
RSP: 0018:ffffc90006d8f818 EFLAGS: 00010286
RAX: dffffc0000000000 RBX: 0000000000000030 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8b6c0863 RDI: dffffc0000000006
RBP: 0000000000000030 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8b6c0863
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880977ea000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbf9f52c6b0 CR3: 0000000065999000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __kasan_check_byte+0x13/0x50 mm/kasan/common.c:556
 kasan_check_byte include/linux/kasan.h:399 [inline]
 lock_acquire kernel/locking/lockdep.c:5840 [inline]
 lock_acquire+0xfc/0x350 kernel/locking/lockdep.c:5823
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
 _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:356 [inline]
 __ip6_ins_rt net/ipv6/route.c:1350 [inline]
 ip6_ins_rt+0xa1/0x110 net/ipv6/route.c:1361
 __ipv6_ifa_notify+0xa6b/0xd60 net/ipv6/addrconf.c:6286
 ipv6_ifa_notify net/ipv6/addrconf.c:6325 [inline]
 addrconf_dad_completed+0x19a/0x10d0 net/ipv6/addrconf.c:4324
 addrconf_dad_work+0x84d/0x14e0 net/ipv6/addrconf.c:4272
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c5/0x780 kernel/kthread.c:464
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:kasan_byte_accessible+0x15/0x30 mm/kasan/generic.c:199
Code: 00 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 48 b8 00 00 00 00 00 fc ff df 48 c1 ef 03 48 01 c7 <0f> b6 07 3c 07 0f 96 c0 e9 0e 29 4d 09 66 66 2e 0f 1f 84 00 00 00
RSP: 0018:ffffc90006d8f818 EFLAGS: 00010286
RAX: dffffc0000000000 RBX: 0000000000000030 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8b6c0863 RDI: dffffc0000000006
RBP: 0000000000000030 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8b6c0863
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880977ea000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbf9f52c6b0 CR3: 0000000065999000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	0f 1f 00             	nopl   (%rax)
   5:	90                   	nop
   6:	90                   	nop
   7:	90                   	nop
   8:	90                   	nop
   9:	90                   	nop
   a:	90                   	nop
   b:	90                   	nop
   c:	90                   	nop
   d:	90                   	nop
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	66 0f 1f 00          	nopw   (%rax)
  19:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  20:	fc ff df
  23:	48 c1 ef 03          	shr    $0x3,%rdi
  27:	48 01 c7             	add    %rax,%rdi
* 2a:	0f b6 07             	movzbl (%rdi),%eax <-- trapping instruction
  2d:	3c 07                	cmp    $0x7,%al
  2f:	0f 96 c0             	setbe  %al
  32:	e9 0e 29 4d 09       	jmp    0x94d2945
  37:	66                   	data16
  38:	66                   	data16
  39:	2e                   	cs
  3a:	0f                   	.byte 0xf
  3b:	1f                   	(bad)
  3c:	84 00                	test   %al,(%rax)

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/05/15 05:42 upstream c94d59a126cb d6b2ee52 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 general protection fault in ip6_ins_rt
* Struck through repros no longer work on HEAD.