[v6.1] BUG: unable to handle kernel paging request in br_del_frame

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: e4f7d8be268e Linux 6.1.182
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14454c79580000
kernel config: https://syzkaller.appspot.com/x/.config?x=872c04466179833f
dashboard link: https://syzkaller.appspot.com/bug?extid=5c4853fd75ad126b1c29
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17187479580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7cd9b1875376/disk-e4f7d8be.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4b5d35d18c31/vmlinux-e4f7d8be.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d5ee64c2af77/Image-e4f7d8be.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5c4853...@syzkaller.appspotmail.com

device bridge_slave_1 left promiscuous mode
bridge0: port 2(bridge_slave_1) entered disabled state
device bridge_slave_0 left promiscuous mode
bridge0: port 1(bridge_slave_0) entered disabled state
Unable to handle kernel paging request at virtual address fbd5200000000024
KASAN: maybe wild-memory-access in range [0xdead000000000120-0xdead000000000127]
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
[fbd5200000000024] address between user and kernel address ranges
Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 4413 Comm: kworker/u4:5 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/07/2026
Workqueue: netns cleanup_net
pstate: 62400005 (nZCv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : __hlist_del include/linux/list.h:884 [inline]
pc : hlist_del_rcu include/linux/rculist.h:513 [inline]
pc : br_del_frame+0xcc/0x158 net/bridge/br_input.c:445
lr : br_del_frame+0x2c/0x158 net/bridge/br_input.c:440
sp : ffff800020e477a0
x29: ffff800020e477a0 x28: 1fffe0001b138600 x27: dfff800000000000
x26: dead000000000122 x25: dfff800000000000 x24: 1fffe0001b551101
x23: 1ffff00002a7384b x22: dfff800000000000 x21: 0000000000000000
x20: ffff80001539c258 x19: dead000000000122 x18: 1fffe00033e7277e
x17: ffff80001537d000 x16: ffff8000082dd248 x15: 0000000000000000
x14: 0000000000000001 x13: 1fffe00033e728a8 x12: 0000000000000000
x11: ff00800010b6d980 x10: 0000000000000000 x9 : ffff800010b6d980
x8 : 1bd5a00000000024 x7 : ffff80000836192c x6 : 0000000000000000
x5 : 0000000000000080 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000006 x1 : ffff80001539c240 x0 : ffff0000d1b24c80
Call trace:
__hlist_del include/linux/list.h:884 [inline]
hlist_del_rcu include/linux/rculist.h:513 [inline]
br_del_frame+0xcc/0x158 net/bridge/br_input.c:445
mep_delete_implementation+0x268/0x2b4 net/bridge/br_cfm.c:591
br_cfm_port_del+0x108/0x1bc net/bridge/br_cfm.c:872
del_nbp+0x154/0x910 net/bridge/br_if.c:347
br_dev_delete+0x70/0x134 net/bridge/br_if.c:386
default_device_exit_batch+0x7e4/0xa70 net/core/dev.c:11544
ops_exit_list net/core/net_namespace.c:177 [inline]
cleanup_net+0x650/0xa90 net/core/net_namespace.c:640
process_one_work+0x7e4/0x13bc kernel/workqueue.c:2292
worker_thread+0x8cc/0xfe8 kernel/workqueue.c:2439
kthread+0x254/0x2e0 kernel/kthread.c:376
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850
Code: aa1403e0 97d2209e f9400293 d343fe68 (38766908)
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
0: aa1403e0 mov x0, x20
4: 97d2209e bl 0xffffffffff48827c
8: f9400293 ldr x19, [x20]
c: d343fe68 lsr x8, x19, #3
* 10: 38766908 ldrb w8, [x8, x22] <-- trapping instruction


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