[syzbot] [usb?] KMSAN: uninit-value in usbnet_probe (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 02ddfb981de8 Merge tag 'scsi-fixes' of git://git.kernel.or..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=128254d4580000
kernel config: https://syzkaller.appspot.com/x/.config?x=9dc42c34a3f5c357
dashboard link: https://syzkaller.appspot.com/bug?extid=3b6b9ff7b80430020c7b
compiler: Debian clang version 20.1.2 (++20250402124445+58df0ef89dd6-1~exp1~20250402004600.97), Debian LLD 20.1.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=168254d4580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16811768580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/5ca57f5a3f77/disk-02ddfb98.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3f23cbc11e68/vmlinux-02ddfb98.xz
kernel image: https://storage.googleapis.com/syzbot-assets/73e63afac354/bzImage-02ddfb98.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3b6b9f...@syzkaller.appspotmail.com

aqc111 1-1:1.105 (unnamed net_device) (uninitialized): Failed to read(0x1) reg index 0x0001: -71
aqc111 1-1:1.105 (unnamed net_device) (uninitialized): Failed to read(0x1) reg index 0x0001: -71
aqc111 1-1:1.105 (unnamed net_device) (uninitialized): Failed to read(0x1) reg index 0x0001: -71
=====================================================
BUG: KMSAN: uninit-value in is_valid_ether_addr include/linux/etherdevice.h:208 [inline]
BUG: KMSAN: uninit-value in usbnet_probe+0x2e57/0x4390 drivers/net/usb/usbnet.c:1830
is_valid_ether_addr include/linux/etherdevice.h:208 [inline]
usbnet_probe+0x2e57/0x4390 drivers/net/usb/usbnet.c:1830
usb_probe_interface+0xd01/0x1310 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x4d1/0xd90 drivers/base/dd.c:658
__driver_probe_device+0x268/0x380 drivers/base/dd.c:800
driver_probe_device+0x70/0x8b0 drivers/base/dd.c:830
__device_attach_driver+0x4ee/0x950 drivers/base/dd.c:958
bus_for_each_drv+0x3e0/0x680 drivers/base/bus.c:462
__device_attach+0x3c8/0x5c0 drivers/base/dd.c:1030
device_initial_probe+0x33/0x40 drivers/base/dd.c:1079
bus_probe_device+0x3ba/0x5e0 drivers/base/bus.c:537
device_add+0x12a9/0x1c10 drivers/base/core.c:3666
usb_set_configuration+0x3493/0x3b70 drivers/usb/core/message.c:2210
usb_generic_driver_probe+0xfc/0x290 drivers/usb/core/generic.c:250
usb_probe_device+0x38a/0x690 drivers/usb/core/driver.c:291
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x4d1/0xd90 drivers/base/dd.c:658
__driver_probe_device+0x268/0x380 drivers/base/dd.c:800
driver_probe_device+0x70/0x8b0 drivers/base/dd.c:830
__device_attach_driver+0x4ee/0x950 drivers/base/dd.c:958
bus_for_each_drv+0x3e0/0x680 drivers/base/bus.c:462
__device_attach+0x3c8/0x5c0 drivers/base/dd.c:1030
device_initial_probe+0x33/0x40 drivers/base/dd.c:1079
bus_probe_device+0x3ba/0x5e0 drivers/base/bus.c:537
device_add+0x12a9/0x1c10 drivers/base/core.c:3666
usb_new_device+0x104b/0x20c0 drivers/usb/core/hub.c:2663
hub_port_connect drivers/usb/core/hub.c:5531 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5671 [inline]
port_event drivers/usb/core/hub.c:5831 [inline]
hub_event+0x5588/0x7580 drivers/usb/core/hub.c:5913
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xb97/0x1d90 kernel/workqueue.c:3319
worker_thread+0xedf/0x1590 kernel/workqueue.c:3400
kthread+0xd59/0xf00 kernel/kthread.c:464
ret_from_fork+0x6e/0x90 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Uninit was stored to memory at:
dev_addr_mod+0xb0/0x550 net/core/dev_addr_lists.c:582
__dev_addr_set include/linux/netdevice.h:4874 [inline]
eth_hw_addr_set include/linux/etherdevice.h:325 [inline]
aqc111_bind+0x35f/0x1150 drivers/net/usb/aqc111.c:717
usbnet_probe+0xbe6/0x4390 drivers/net/usb/usbnet.c:1772
usb_probe_interface+0xd01/0x1310 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x4d1/0xd90 drivers/base/dd.c:658
__driver_probe_device+0x268/0x380 drivers/base/dd.c:800
driver_probe_device+0x70/0x8b0 drivers/base/dd.c:830
__device_attach_driver+0x4ee/0x950 drivers/base/dd.c:958
bus_for_each_drv+0x3e0/0x680 drivers/base/bus.c:462
__device_attach+0x3c8/0x5c0 drivers/base/dd.c:1030
device_initial_probe+0x33/0x40 drivers/base/dd.c:1079
bus_probe_device+0x3ba/0x5e0 drivers/base/bus.c:537
device_add+0x12a9/0x1c10 drivers/base/core.c:3666
usb_set_configuration+0x3493/0x3b70 drivers/usb/core/message.c:2210
usb_generic_driver_probe+0xfc/0x290 drivers/usb/core/generic.c:250
usb_probe_device+0x38a/0x690 drivers/usb/core/driver.c:291
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x4d1/0xd90 drivers/base/dd.c:658
__driver_probe_device+0x268/0x380 drivers/base/dd.c:800
driver_probe_device+0x70/0x8b0 drivers/base/dd.c:830
__device_attach_driver+0x4ee/0x950 drivers/base/dd.c:958
bus_for_each_drv+0x3e0/0x680 drivers/base/bus.c:462
__device_attach+0x3c8/0x5c0 drivers/base/dd.c:1030
device_initial_probe+0x33/0x40 drivers/base/dd.c:1079
bus_probe_device+0x3ba/0x5e0 drivers/base/bus.c:537
device_add+0x12a9/0x1c10 drivers/base/core.c:3666
usb_new_device+0x104b/0x20c0 drivers/usb/core/hub.c:2663
hub_port_connect drivers/usb/core/hub.c:5531 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5671 [inline]
port_event drivers/usb/core/hub.c:5831 [inline]
hub_event+0x5588/0x7580 drivers/usb/core/hub.c:5913
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xb97/0x1d90 kernel/workqueue.c:3319
worker_thread+0xedf/0x1590 kernel/workqueue.c:3400
kthread+0xd59/0xf00 kernel/kthread.c:464
ret_from_fork+0x6e/0x90 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Uninit was stored to memory at:
ether_addr_copy include/linux/etherdevice.h:305 [inline]
aqc111_read_perm_mac drivers/net/usb/aqc111.c:663 [inline]
aqc111_bind+0x794/0x1150 drivers/net/usb/aqc111.c:713
usbnet_probe+0xbe6/0x4390 drivers/net/usb/usbnet.c:1772
usb_probe_interface+0xd01/0x1310 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x4d1/0xd90 drivers/base/dd.c:658
__driver_probe_device+0x268/0x380 drivers/base/dd.c:800
driver_probe_device+0x70/0x8b0 drivers/base/dd.c:830
__device_attach_driver+0x4ee/0x950 drivers/base/dd.c:958
bus_for_each_drv+0x3e0/0x680 drivers/base/bus.c:462
__device_attach+0x3c8/0x5c0 drivers/base/dd.c:1030
device_initial_probe+0x33/0x40 drivers/base/dd.c:1079
bus_probe_device+0x3ba/0x5e0 drivers/base/bus.c:537
device_add+0x12a9/0x1c10 drivers/base/core.c:3666
usb_set_configuration+0x3493/0x3b70 drivers/usb/core/message.c:2210
usb_generic_driver_probe+0xfc/0x290 drivers/usb/core/generic.c:250
usb_probe_device+0x38a/0x690 drivers/usb/core/driver.c:291
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x4d1/0xd90 drivers/base/dd.c:658
__driver_probe_device+0x268/0x380 drivers/base/dd.c:800
driver_probe_device+0x70/0x8b0 drivers/base/dd.c:830
__device_attach_driver+0x4ee/0x950 drivers/base/dd.c:958
bus_for_each_drv+0x3e0/0x680 drivers/base/bus.c:462
__device_attach+0x3c8/0x5c0 drivers/base/dd.c:1030
device_initial_probe+0x33/0x40 drivers/base/dd.c:1079
bus_probe_device+0x3ba/0x5e0 drivers/base/bus.c:537
device_add+0x12a9/0x1c10 drivers/base/core.c:3666
usb_new_device+0x104b/0x20c0 drivers/usb/core/hub.c:2663
hub_port_connect drivers/usb/core/hub.c:5531 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5671 [inline]
port_event drivers/usb/core/hub.c:5831 [inline]
hub_event+0x5588/0x7580 drivers/usb/core/hub.c:5913
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xb97/0x1d90 kernel/workqueue.c:3319
worker_thread+0xedf/0x1590 kernel/workqueue.c:3400
kthread+0xd59/0xf00 kernel/kthread.c:464
ret_from_fork+0x6e/0x90 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Local variable buf.i created at:
aqc111_read_perm_mac drivers/net/usb/aqc111.c:656 [inline]
aqc111_bind+0x221/0x1150 drivers/net/usb/aqc111.c:713
usbnet_probe+0xbe6/0x4390 drivers/net/usb/usbnet.c:1772

CPU: 0 UID: 0 PID: 1877 Comm: kworker/0:2 Not tainted 6.15.0-rc3-syzkaller-00094-g02ddfb981de8 #0 PREEMPT(undef)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
Workqueue: usb_hub_wq hub_event
=====================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

[Nikita Zhandarovich]

#syz test

---
drivers/net/usb/aqc111.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/net/usb/aqc111.c b/drivers/net/usb/aqc111.c
index ff5be2cbf17b..f647c4673256 100644
--- a/drivers/net/usb/aqc111.c
+++ b/drivers/net/usb/aqc111.c
@@ -30,10 +30,13 @@ static int aqc111_read_cmd_nopm(struct usbnet *dev, u8 cmd, u16 value,
ret = usbnet_read_cmd_nopm(dev, cmd, USB_DIR_IN | USB_TYPE_VENDOR |
USB_RECIP_DEVICE, value, index, data, size);

- if (unlikely(ret < 0))
+ if (unlikely(ret < size)) {
+ ret = ret < 0 ? ret: -ENODATA;
+
netdev_warn(dev->net,
"Failed to read(0x%x) reg index 0x%04x: %d\n",
cmd, index, ret);
+ }

return ret;
}
@@ -46,10 +49,13 @@ static int aqc111_read_cmd(struct usbnet *dev, u8 cmd, u16 value,
ret = usbnet_read_cmd(dev, cmd, USB_DIR_IN | USB_TYPE_VENDOR |
USB_RECIP_DEVICE, value, index, data, size);

- if (unlikely(ret < 0))
+ if (unlikely(ret < size)) {
+ ret = ret < 0 ? ret: -ENODATA;
+
netdev_warn(dev->net,
"Failed to read(0x%x) reg index 0x%04x: %d\n",
cmd, index, ret);
+ }

return ret;
}

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+3b6b9f...@syzkaller.appspotmail.com
Tested-by: syzbot+3b6b9f...@syzkaller.appspotmail.com

Tested on:

commit: a5806cd5 Linux 6.15-rc7
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15815e70580000
kernel config: https://syzkaller.appspot.com/x/.config?x=8610b3b94c7a5632

dashboard link: https://syzkaller.appspot.com/bug?extid=3b6b9ff7b80430020c7b
compiler: Debian clang version 20.1.2 (++20250402124445+58df0ef89dd6-1~exp1~20250402004600.97), Debian LLD 20.1.2

patch: https://syzkaller.appspot.com/x/patch.diff?x=10b331f4580000

Note: testing is done by a robot and is best-effort only.