syzbot

Oops: general protection fault, probably for non-canonical address 0xdffffc001fffc000: 0000 [#1] SMP KASAN NOPTI
KASAN: probably user-memory-access in range [0x00000000fffe0000-0x00000000fffe0007]
CPU: 0 UID: 0 PID: 5919 Comm: kworker/0:5 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: mld mld_query_work
RIP: 0010:mld_clear_delrec+0x2f0/0x6d0 net/ipv6/mcast.c:840
Code: 20 00 0f 85 b4 03 00 00 49 8b 5d 28 49 c7 45 28 00 00 00 00 48 85 db 75 37 e9 d4 00 00 00 e8 b7 49 71 f7 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 0f 85 70 03 00 00 48 8b 2b 48 8d 7b 30 48 89 de e8
RSP: 0018:ffffc9000237fa90 EFLAGS: 00010206
RAX: 000000001fffc000 RBX: 00000000fffe0000 RCX: ffffffff8a4a42b0
RDX: ffff888026aba440 RSI: ffffffff8a4a4249 RDI: 0000000000000005
RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff8880579da800 R14: ffff88807a55b000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881246b9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000234030 CR3: 00000000263b8000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 mld_process_v1 net/ipv6/mcast.c:1390 [inline]
 __mld_query_work net/ipv6/mcast.c:1476 [inline]
 mld_query_work+0xf2f/0x3780 net/ipv6/mcast.c:1568
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x5d7/0x6f0 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:mld_clear_delrec+0x2f0/0x6d0 net/ipv6/mcast.c:840
Code: 20 00 0f 85 b4 03 00 00 49 8b 5d 28 49 c7 45 28 00 00 00 00 48 85 db 75 37 e9 d4 00 00 00 e8 b7 49 71 f7 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 0f 85 70 03 00 00 48 8b 2b 48 8d 7b 30 48 89 de e8
RSP: 0018:ffffc9000237fa90 EFLAGS: 00010206
RAX: 000000001fffc000 RBX: 00000000fffe0000 RCX: ffffffff8a4a42b0
RDX: ffff888026aba440 RSI: ffffffff8a4a4249 RDI: 0000000000000005
RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff8880579da800 R14: ffff88807a55b000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881246b9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000057030 CR3: 000000007c9be000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	20 00                	and    %al,(%rax)
   2:	0f 85 b4 03 00 00    	jne    0x3bc
   8:	49 8b 5d 28          	mov    0x28(%r13),%rbx
   c:	49 c7 45 28 00 00 00 	movq   $0x0,0x28(%r13)
  13:	00
  14:	48 85 db             	test   %rbx,%rbx
  17:	75 37                	jne    0x50
  19:	e9 d4 00 00 00       	jmp    0xf2
  1e:	e8 b7 49 71 f7       	call   0xf77149da
  23:	48 89 d8             	mov    %rbx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1) <-- trapping instruction
  2f:	0f 85 70 03 00 00    	jne    0x3a5
  35:	48 8b 2b             	mov    (%rbx),%rbp
  38:	48 8d 7b 30          	lea    0x30(%rbx),%rdi
  3c:	48 89 de             	mov    %rbx,%rsi
  3f:	e8                   	.byte 0xe8