[syzbot] [usb?] UBSAN: shift-out-of-bounds in ax88772_bind

[syzbot <syzbot+20537064367a0f98d597@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    d7ee5bdce789 Merge tag 'firewire-fixes-6.17-rc1' of git://..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11835af0580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=412ee2f8b704a5e6
dashboard link: https://syzkaller.appspot.com/bug?extid=20537064367a0f98d597
compiler:       Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11d253a2580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/62d2c52c687a/disk-d7ee5bdc.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f827f7b0a929/vmlinux-d7ee5bdc.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0babf789124a/bzImage-d7ee5bdc.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+20537064367a0f98d597@syzkaller.appspotmail.com

asix 1-1:0.0 (unnamed net_device) (uninitialized): Failed to read reg index 0x0000: -71
asix 1-1:0.0 (unnamed net_device) (uninitialized): Error reading Medium Status register: ffffffb9
------------[ cut here ]------------
UBSAN: shift-out-of-bounds in drivers/net/usb/asix_devices.c:679:27
shift exponent 240 is too large for 64-bit type 'unsigned long'
CPU: 1 UID: 0 PID: 6020 Comm: kworker/1:4 Not tainted 6.17.0-rc1-syzkaller-00116-gd7ee5bdce789 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 ubsan_epilogue+0xa/0x40 lib/ubsan.c:233
 __ubsan_handle_shift_out_of_bounds+0x386/0x410 lib/ubsan.c:494
 ax88772_init_mdio drivers/net/usb/asix_devices.c:679 [inline]
 ax88772_bind+0xdcf/0xfa0 drivers/net/usb/asix_devices.c:910
 usbnet_probe+0xa93/0x2870 drivers/net/usb/usbnet.c:1781
 usb_probe_interface+0x665/0xc30 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x26a/0x9e0 drivers/base/dd.c:659
 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:801
 driver_probe_device+0x4f/0x430 drivers/base/dd.c:831
 __device_attach_driver+0x2ce/0x530 drivers/base/dd.c:959
 bus_for_each_drv+0x251/0x2e0 drivers/base/bus.c:462
 __device_attach+0x2b8/0x400 drivers/base/dd.c:1031
 bus_probe_device+0x185/0x260 drivers/base/bus.c:537
 device_add+0x7b6/0xb50 drivers/base/core.c:3689
 usb_set_configuration+0x1a87/0x20e0 drivers/usb/core/message.c:2210
 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
 usb_probe_device+0x1c4/0x390 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x26a/0x9e0 drivers/base/dd.c:659
 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:801
 driver_probe_device+0x4f/0x430 drivers/base/dd.c:831
 __device_attach_driver+0x2ce/0x530 drivers/base/dd.c:959
 bus_for_each_drv+0x251/0x2e0 drivers/base/bus.c:462
 __device_attach+0x2b8/0x400 drivers/base/dd.c:1031
 bus_probe_device+0x185/0x260 drivers/base/bus.c:537
 device_add+0x7b6/0xb50 drivers/base/core.c:3689
 usb_new_device+0xa39/0x16f0 drivers/usb/core/hub.c:2694
 hub_port_connect drivers/usb/core/hub.c:5566 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5706 [inline]
 port_event drivers/usb/core/hub.c:5870 [inline]
 hub_event+0x2958/0x4a20 drivers/usb/core/hub.c:5952
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
---[ end trace ]---


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