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: 1 UID: 0 PID: 7583 Comm: kworker/u8:39 Not tainted 6.16.0-rc7-syzkaller-00105-g2942242dde89 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: netns cleanup_net
RIP: 0010:ip6_mc_clear_src+0x119/0x4e0 net/ipv6/mcast.c:2599
Code: ff ff ff e8 89 0a 42 01 89 c5 31 ff 89 c6 e8 ae 89 94 f7 85 ed 74 45 e8 65 85 94 f7 eb 05 e8 5e 85 94 f7 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 e7 e8 48 97 f6 f7 49 8b 2c 24 49 8d 7c
RSP: 0018:ffffc9000d0cf2e0 EFLAGS: 00010216
RAX: 000000001fffc000 RBX: 1ffff11003ff0882 RCX: ffff88807ce61e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffffffff8fa1ddf7 R09: 1ffffffff1f43bbe
R10: dffffc0000000000 R11: fffffbfff1f43bbf R12: 00000000fffe0000
R13: dffffc0000000000 R14: 0000000000000538 R15: ffff88801ff84410
FS:  0000000000000000(0000) GS:ffff888125d23000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4bc3b53000 CR3: 000000005c881000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 mld_clear_delrec+0x105/0x5d0 net/ipv6/mcast.c:826
 ipv6_mc_destroy_dev+0x45/0x5a0 net/ipv6/mcast.c:2842
 addrconf_ifdown+0x139e/0x1880 net/ipv6/addrconf.c:3995
 addrconf_notify+0x1bc/0x1010 net/ipv6/addrconf.c:-1
 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]
 call_netdevice_notifiers net/core/dev.c:2282 [inline]
 unregister_netdevice_many_notify+0x15d8/0x2320 net/core/dev.c:12077
 unregister_netdevice_many net/core/dev.c:12140 [inline]
 default_device_exit_batch+0x819/0x890 net/core/dev.c:12644
 ops_exit_list net/core/net_namespace.c:206 [inline]
 ops_undo_list+0x525/0x990 net/core/net_namespace.c:253
 cleanup_net+0x4c5/0x800 net/core/net_namespace.c:686
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x711/0x8a0 kernel/kthread.c:464
 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:ip6_mc_clear_src+0x119/0x4e0 net/ipv6/mcast.c:2599
Code: ff ff ff e8 89 0a 42 01 89 c5 31 ff 89 c6 e8 ae 89 94 f7 85 ed 74 45 e8 65 85 94 f7 eb 05 e8 5e 85 94 f7 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 e7 e8 48 97 f6 f7 49 8b 2c 24 49 8d 7c
RSP: 0018:ffffc9000d0cf2e0 EFLAGS: 00010216
RAX: 000000001fffc000 RBX: 1ffff11003ff0882 RCX: ffff88807ce61e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffffffff8fa1ddf7 R09: 1ffffffff1f43bbe
R10: dffffc0000000000 R11: fffffbfff1f43bbf R12: 00000000fffe0000
R13: dffffc0000000000 R14: 0000000000000538 R15: ffff88801ff84410
FS:  0000000000000000(0000) GS:ffff888125c23000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31d0f000 CR3: 0000000030bd9000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess), 3 bytes skipped:
   0:	e8 89 0a 42 01       	call   0x1420a8e
   5:	89 c5                	mov    %eax,%ebp
   7:	31 ff                	xor    %edi,%edi
   9:	89 c6                	mov    %eax,%esi
   b:	e8 ae 89 94 f7       	call   0xf79489be
  10:	85 ed                	test   %ebp,%ebp
  12:	74 45                	je     0x59
  14:	e8 65 85 94 f7       	call   0xf794857e
  19:	eb 05                	jmp    0x20
  1b:	e8 5e 85 94 f7       	call   0xf794857e
  20:	4c 89 e0             	mov    %r12,%rax
  23:	48 c1 e8 03          	shr    $0x3,%rax
* 27:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1) <-- trapping instruction
  2c:	74 08                	je     0x36
  2e:	4c 89 e7             	mov    %r12,%rdi
  31:	e8 48 97 f6 f7       	call   0xf7f6977e
  36:	49 8b 2c 24          	mov    (%r12),%rbp
  3a:	49                   	rex.WB
  3b:	8d                   	.byte 0x8d
  3c:	7c                   	.byte 0x7c