[v5.15] BUG: unable to handle kernel paging request in ip6_mc_clear_src

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: c79648372d02 Linux 5.15.189
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=13d686a2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=9e47345638b85bd0
dashboard link: https://syzkaller.appspot.com/bug?extid=a3c14bf2e2a06815bd48
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
userspace arch: arm64

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7ab49562317a/disk-c7964837.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e847ec1e38d3/vmlinux-c7964837.xz
kernel image: https://storage.googleapis.com/syzbot-assets/263158c6371c/Image-c7964837.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a3c14b...@syzkaller.appspotmail.com

Unable to handle kernel paging request at virtual address dfff80001fffe000
Mem abort info:
ESR = 0x0000000096000007
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x07: level 3 translation fault
Data abort info:
ISV = 0, ISS = 0x00000007
CM = 0, WnR = 0
[dfff80001fffe000] address between user and kernel address ranges
Internal error: Oops: 0000000096000007 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 4166 Comm: kworker/u4:10 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: netns cleanup_net
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : ip6_mc_clear_src+0x120/0x4b8 net/ipv6/mcast.c:2557
lr : ip6_mc_clear_src+0x114/0x4b8 net/ipv6/mcast.c:2557
sp : ffff80001b8b7240
x29: ffff80001b8b7240 x28: 1fffe00019ee6c02 x27: 1fffe00019ee6c05
x26: dfff800000000000 x25: 0000000000000001 x24: ffff800012dc5960
x23: ffff8000165b2000 x22: 00000000ffff0000 x21: ffff0000cf736010
x20: ffff0000cf736028 x19: ffff0000cf736000 x18: 0000000000000000
x17: 0000000000000000 x16: ffff8000082bf708 x15: 000000000000030a
x14: 00000000ffff8000 x13: 1ffff0000282e06b x12: 0000000000ff0100
x11: 0000000000000000 x10: 0000000000000000 x9 : ffff8000101cebc8
x8 : 000000001fffe000 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000080 x4 : 0000000000000000 x3 : 0000000000000010
x2 : 0000000000000006 x1 : 0000000000000001 x0 : 0000000000000000
Call trace:
ip6_mc_clear_src+0x120/0x4b8 net/ipv6/mcast.c:2557
__ipv6_dev_mc_dec+0x29c/0x320 net/ipv6/mcast.c:979
addrconf_leave_solict net/ipv6/addrconf.c:2214 [inline]
__ipv6_ifa_notify+0x5e8/0xbf4 net/ipv6/addrconf.c:6202
addrconf_ifdown+0xc6c/0x1688 net/ipv6/addrconf.c:3900
addrconf_notify+0x2f4/0xc6c net/ipv6/addrconf.c:-1
notifier_call_chain kernel/notifier.c:83 [inline]
raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:391
call_netdevice_notifiers_info net/core/dev.c:2049 [inline]
call_netdevice_notifiers_extack net/core/dev.c:2061 [inline]
call_netdevice_notifiers net/core/dev.c:2075 [inline]
unregister_netdevice_many+0xe10/0x17d0 net/core/dev.c:11134
default_device_exit_batch+0x444/0x4a4 net/core/dev.c:11667
ops_exit_list net/core/net_namespace.c:177 [inline]
cleanup_net+0x644/0xa98 net/core/net_namespace.c:635
process_one_work+0x79c/0x1140 kernel/workqueue.c:2310
worker_thread+0x8f4/0x101c kernel/workqueue.c:2457
kthread+0x374/0x454 kernel/kthread.c:334
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:855
Code: 960aaa0f 14000002 960aaa0d d343fec8 (387a6908)
---[ end trace 88970e3d4acd26aa ]---
----------------
Code disassembly (best guess):
0: 960aaa0f bl 0xfffffffff82aa83c
4: 14000002 b 0xc
8: 960aaa0d bl 0xfffffffff82aa83c
c: d343fec8 lsr x8, x22, #3
* 10: 387a6908 ldrb w8, [x8, x26] <-- trapping instruction


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.