syzbot

Oops: general protection fault, probably for non-canonical address 0xdffffc001fffe000: 0000 [#1] SMP KASAN NOPTI
KASAN: probably user-memory-access in range [0x00000000ffff0000-0x00000000ffff0007]
CPU: 0 UID: 0 PID: 5957 Comm: kworker/0:7 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: mld mld_ifc_work
RIP: 0010:add_grec+0xac4/0x1720 net/ipv6/mcast.c:1960
Code: 42 72 70 f7 e8 9d 97 48 01 31 ff 41 89 c5 89 c6 e8 71 6d 70 f7 45 85 ed 0f 85 76 02 00 00 e8 23 72 70 f7 4c 89 f8 48 c1 e8 03 <42> 80 3c 20 00 0f 85 2d 0a 00 00 48 8b 7c 24 70 44 8b 44 24 64 4c
RSP: 0018:ffffc900031d7ae0 EFLAGS: 00010206
RAX: 000000001fffe000 RBX: 0000000000000000 RCX: ffffffff8a4b1c75
RDX: ffff888035f92440 RSI: ffffffff8a4b19dd RDI: 0000000000000005
RBP: ffffc900031d7be8 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000001 R15: 00000000ffff0000
FS:  0000000000000000(0000) GS:ffff8881246b9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200001000000 CR3: 000000000e380000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 mld_send_cr net/ipv6/mcast.c:2145 [inline]
 mld_ifc_work+0x392/0xbf0 net/ipv6/mcast.c:2698
 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:add_grec+0xac4/0x1720 net/ipv6/mcast.c:1960
Code: 42 72 70 f7 e8 9d 97 48 01 31 ff 41 89 c5 89 c6 e8 71 6d 70 f7 45 85 ed 0f 85 76 02 00 00 e8 23 72 70 f7 4c 89 f8 48 c1 e8 03 <42> 80 3c 20 00 0f 85 2d 0a 00 00 48 8b 7c 24 70 44 8b 44 24 64 4c
RSP: 0018:ffffc900031d7ae0 EFLAGS: 00010206
RAX: 000000001fffe000 RBX: 0000000000000000 RCX: ffffffff8a4b1c75
RDX: ffff888035f92440 RSI: ffffffff8a4b19dd RDI: 0000000000000005
RBP: ffffc900031d7be8 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000001 R15: 00000000ffff0000
FS:  0000000000000000(0000) GS:ffff8881246b9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555c4725c8 CR3: 00000000775dd000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	42 72 70             	rex.X jb 0x73
   3:	f7 e8                	imul   %eax
   5:	9d                   	popf
   6:	97                   	xchg   %eax,%edi
   7:	48 01 31             	add    %rsi,(%rcx)
   a:	ff 41 89             	incl   -0x77(%rcx)
   d:	c5 89 c6 e8 71       	vshufpd $0x71,%xmm0,%xmm14,%xmm5
  12:	6d                   	insl   (%dx),%es:(%rdi)
  13:	70 f7                	jo     0xc
  15:	45 85 ed             	test   %r13d,%r13d
  18:	0f 85 76 02 00 00    	jne    0x294
  1e:	e8 23 72 70 f7       	call   0xf7707246
  23:	4c 89 f8             	mov    %r15,%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 2d 0a 00 00    	jne    0xa62
  35:	48 8b 7c 24 70       	mov    0x70(%rsp),%rdi
  3a:	44 8b 44 24 64       	mov    0x64(%rsp),%r8d
  3f:	4c                   	rex.WR