Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 UID: 0 PID: 11 Comm: kworker/u4:0 Not tainted 6.14.0-rc2-syzkaller-00034-gfebbc555cf0f #0
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:add_grec+0xc0/0x19a0 net/ipv6/mcast.c:1919
Code: 8b 5d 00 89 de 83 e6 08 31 ff e8 db a9 1e f7 83 e3 08 75 70 48 8b 4c 24 48 48 89 c8 48 c1 e8 03 48 ba 00 00 00 00 00 fc ff df <80> 3c 10 00 74 0f 48 8b 7c 24 48 e8 90 3e 85 f7 48 8b 4c 24 48 48
RSP: 0018:ffffc900001d7798 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffffffff8aa0aa05 R09: 0000000000000001
R10: 00000000000002ff R11: c1a88cff01000000 R12: ffff88804404d000
R13: ffff88804404d0f0 R14: ffff888051f72b40 R15: 0000000000000004
FS:  0000000000000000(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b87bd7d0c8 CR3: 0000000011ddc000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 mld_send_initial_cr+0x228/0x4b0 net/ipv6/mcast.c:2277
 ipv6_mc_dad_complete+0x88/0x490 net/ipv6/mcast.c:2288
 addrconf_dad_completed+0x712/0xcd0 net/ipv6/addrconf.c:4336
 addrconf_dad_work+0xdbc/0x16a0
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317
 worker_thread+0x870/0xd30 kernel/workqueue.c:3398
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	8b 5d 00             	mov    0x0(%rbp),%ebx
   3:	89 de                	mov    %ebx,%esi
   5:	83 e6 08             	and    $0x8,%esi
   8:	31 ff                	xor    %edi,%edi
   a:	e8 db a9 1e f7       	call   0xf71ea9ea
   f:	83 e3 08             	and    $0x8,%ebx
  12:	75 70                	jne    0x84
  14:	48 8b 4c 24 48       	mov    0x48(%rsp),%rcx
  19:	48 89 c8             	mov    %rcx,%rax
  1c:	48 c1 e8 03          	shr    $0x3,%rax
  20:	48 ba 00 00 00 00 00 	movabs $0xdffffc0000000000,%rdx
  27:	fc ff df
* 2a:	80 3c 10 00          	cmpb   $0x0,(%rax,%rdx,1) <-- trapping instruction
  2e:	74 0f                	je     0x3f
  30:	48 8b 7c 24 48       	mov    0x48(%rsp),%rdi
  35:	e8 90 3e 85 f7       	call   0xf7853eca
  3a:	48 8b 4c 24 48       	mov    0x48(%rsp),%rcx
  3f:	48                   	rex.W