BUG: unable to handle kernel paging request in __ip_mc_dec

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	general protection fault in __ip_mc_dec_group net	2				85	5d09h	120d	0/29	upstream: reported on 2025/05/06 09:31
Unable to handle kernel paging request at virtual address 00000000fffd0d60
Mem abort info:
  ESR = 0x0000000096000004
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x04: level 0 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000004
  CM = 0, WnR = 0
user pgtable: 4k pages, 48-bit VAs, pgdp=0000000143686000
[00000000fffd0d60] pgd=0000000000000000, p4d=0000000000000000
Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 1873 Comm: kworker/u4:5 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
Workqueue: netns cleanup_net
pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : ip_mc_hash_remove net/ipv4/igmp.c:1428 [inline]
pc : __ip_mc_dec_group+0x328/0x604 net/ipv4/igmp.c:1688
lr : ip_mc_hash_remove net/ipv4/igmp.c:1428 [inline]
lr : __ip_mc_dec_group+0x2b8/0x604 net/ipv4/igmp.c:1688
sp : ffff8000257c7520
x29: ffff8000257c7530 x28: 1fffe0001eac1684 x27: dfff800000000000
x26: 000000001fffa1ac x25: ffff800013a6df80 x24: ffff800013a6df60
x23: 00000000fffd0d60 x22: ffff0000f560b420 x21: ffff800017a8a000
x20: ffff0000ca58b600 x19: ffff0000f560b400 x18: ffff800011abbcc0
x17: ffff8000181f9000 x16: ffff8000082d0e24 x15: 0000000000000000
x14: 000000000000030a x13: 1ffff00002a180b1 x12: 0000000000ff0100
x11: ff0080001054cdb0 x10: 0000000000000000 x9 : ffff80001054cdb0
x8 : 0000000000000000 x7 : ffff80000a895578 x6 : 0000000000000000
x5 : 0000000000000080 x4 : 0000000000000001 x3 : ffff8000082c8814
x2 : 0000000000000000 x1 : 0000000000000001 x0 : 0000000000000001
Call trace:
 ip_mc_hash_remove net/ipv4/igmp.c:1428 [inline]
 __ip_mc_dec_group+0x328/0x604 net/ipv4/igmp.c:1688
 ip_mc_dec_group include/linux/igmp.h:135 [inline]
 ip_mc_down+0x2d4/0x3b8 net/ipv4/igmp.c:1752
 inetdev_event+0x228/0x12ec net/ipv4/devinet.c:1602
 notifier_call_chain kernel/notifier.c:87 [inline]
 raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:455
 call_netdevice_notifiers_info net/core/dev.c:2001 [inline]
 call_netdevice_notifiers_extack net/core/dev.c:2039 [inline]
 call_netdevice_notifiers net/core/dev.c:2053 [inline]
 dev_close_many+0x2cc/0x440 net/core/dev.c:1601
 unregister_netdevice_many+0x3c4/0x1740 net/core/dev.c:10964
 vti6_exit_batch_net+0x3ac/0x3fc net/ipv6/ip6_vti.c:1191
 ops_exit_list net/core/net_namespace.c:177 [inline]
 cleanup_net+0x644/0xa74 net/core/net_namespace.c:640
 process_one_work+0x7f4/0x13a8 kernel/workqueue.c:2292
 worker_thread+0x8c8/0xfbc kernel/workqueue.c:2439
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850
Code: 387b6b48 34000068 aa1703e0 960e26bf (f94002e8) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	387b6b48 	ldrb	w8, [x26, x27]
   4:	34000068 	cbz	w8, 0x10
   8:	aa1703e0 	mov	x0, x23
   c:	960e26bf 	bl	0xfffffffff8389b08
* 10:	f94002e8 	ldr	x8, [x23] <-- trapping instruction