[moderation] [usb?] BUG: unable to handle kernel paging request in dummy_enable

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 365f9c7a6b81 Merge branches 'for-next/core' and 'for-next/..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=1682703e580000
kernel config: https://syzkaller.appspot.com/x/.config?x=72c97575381cec47
dashboard link: https://syzkaller.appspot.com/bug?extid=50cca254daddfa78df09
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
userspace arch: arm64
CC: [gre...@linuxfoundation.org linux-...@vger.kernel.org linu...@vger.kernel.org]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/eafe0adb7386/disk-365f9c7a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/29422d607579/vmlinux-365f9c7a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/98ca955a8b54/Image-365f9c7a.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+50cca2...@syzkaller.appspotmail.com

Unable to handle kernel paging request at virtual address dfff80000000000c
KASAN: null-ptr-deref in range [0x0000000000000060-0x0000000000000067]
Mem abort info:
ESR = 0x0000000096000005
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x05: level 1 translation fault
Data abort info:
ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
CM = 0, WnR = 0, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0
[dfff80000000000c] address between user and kernel address ranges
Internal error: Oops: 0000000096000005 [#1] SMP
Modules linked in:
CPU: 1 UID: 0 PID: 7550 Comm: syz.6.543 Tainted: G L syzkaller #0 PREEMPT
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026
pstate: 834000c5 (Nzcv daIF +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : dummy_enable+0x178/0x9a4 drivers/usb/gadget/udc/dummy_hcd.c:526
lr : gadget_to_dummy_hcd drivers/usb/gadget/udc/dummy_hcd.c:317 [inline]
lr : dummy_enable+0x144/0x9a4 drivers/usb/gadget/udc/dummy_hcd.c:525
sp : ffff800094e678e0
x29: ffff800094e67900 x28: 1fffe00018f5801b x27: 1fffe00018f5801d
x26: ffff0000c7ac00d8 x25: ffff0000c7ac0c00 x24: 1fffe00018f5818e
x23: dfff800000000000 x22: 0000000000000060 x21: ffff8000873320c0
x20: ffff0000f13b1cc0 x19: ffff0000c7ac00e0 x18: 00000000ffffffff
x17: ffff80008a791000 x16: 0000000000000004 x15: ffff80008a31ada0
x14: ffff80008a590e28 x13: 0000000000000001 x12: 0000000000000004
x11: ffff7000129ccf1c x10: 0000000000080000 x9 : 00000000000006a8
x8 : 000000000000000c x7 : ffff8000836ddfec x6 : 0000000000000000
x5 : 0000000000000030 x4 : 0000000000000000 x3 : ffff8000835b67f0
x2 : 0000000000000002 x1 : ffff0000f264d7c0 x0 : 0000000000000000
Call trace:
dummy_enable+0x178/0x9a4 drivers/usb/gadget/udc/dummy_hcd.c:526 (P)
usb_ep_enable+0xf4/0x608 drivers/usb/gadget/udc/core.c:131
ep_config+0x3d0/0x57c drivers/usb/gadget/legacy/inode.c:799
ep_write_iter+0x38c/0x418 drivers/usb/gadget/legacy/inode.c:681
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x51c/0xa0c fs/read_write.c:687
ksys_write+0x12c/0x228 fs/read_write.c:739
__do_sys_write fs/read_write.c:750 [inline]
__se_sys_write fs/read_write.c:747 [inline]
__arm64_sys_write+0x7c/0x90 fs/read_write.c:747
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736
el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594
Code: 97579764 f94002c8 91018116 d343fec8 (38f76908)
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
0: 97579764 bl 0xfffffffffd5e5d90
4: f94002c8 ldr x8, [x22]
8: 91018116 add x22, x8, #0x60
c: d343fec8 lsr x8, x22, #3
* 10: 38f76908 ldrsb w8, [x8, x23] <-- trapping instruction


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