[syzbot] KMSAN: kernel-usb-infoleak in usbnet_write_cmd (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 81c325bbf94e kmsan: hooks: do not check memory in kmsan_in..
git tree: https://github.com/google/kmsan.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=14a07163b00000
kernel config: https://syzkaller.appspot.com/x/.config?x=2d8b9a11641dc9aa
dashboard link: https://syzkaller.appspot.com/bug?extid=003c0a286b9af5412510
compiler: clang version 14.0.0 (/usr/local/google/src/llvm-git-monorepo 2b554920f11c8b763cd9ed9003f4e19b919b8e1f), GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=100165dbb00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10c97e77b00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+003c0a...@syzkaller.appspotmail.com

usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 1-1: Product: syz
usb 1-1: Manufacturer: syz
usb 1-1: SerialNumber: syz
usb 1-1: config 0 descriptor??
=====================================================
BUG: KMSAN: kernel-usb-infoleak in usb_submit_urb+0x6c1/0x2aa0 drivers/usb/core/urb.c:430
usb_submit_urb+0x6c1/0x2aa0 drivers/usb/core/urb.c:430
usb_start_wait_urb+0x153/0x4b0 drivers/usb/core/message.c:58
usb_internal_control_msg drivers/usb/core/message.c:102 [inline]
usb_control_msg+0x487/0x7c0 drivers/usb/core/message.c:153
__usbnet_write_cmd drivers/net/usb/usbnet.c:2050 [inline]
usbnet_write_cmd+0x3d3/0x480 drivers/net/usb/usbnet.c:2088
mcs7830_set_reg drivers/net/usb/mcs7830.c:117 [inline]
mcs7830_hif_set_mac_address drivers/net/usb/mcs7830.c:138 [inline]
mcs7830_apply_base_config+0xd5/0x8a0 drivers/net/usb/mcs7830.c:387
mcs7830_bind+0x753/0xb70 drivers/net/usb/mcs7830.c:492
usbnet_probe+0x1284/0x4140 drivers/net/usb/usbnet.c:1747
usb_probe_interface+0xf19/0x1600 drivers/usb/core/driver.c:396
really_probe+0x67d/0x1510 drivers/base/dd.c:596
__driver_probe_device+0x3e9/0x530 drivers/base/dd.c:751
driver_probe_device drivers/base/dd.c:781 [inline]
__device_attach_driver+0x79f/0x1120 drivers/base/dd.c:898
bus_for_each_drv+0x2d6/0x3f0 drivers/base/bus.c:427
__device_attach+0x593/0x8e0 drivers/base/dd.c:969
device_initial_probe+0x4a/0x60 drivers/base/dd.c:1016
bus_probe_device+0x17b/0x3e0 drivers/base/bus.c:487
device_add+0x1d3e/0x2400 drivers/base/core.c:3394
usb_set_configuration+0x37e9/0x3ed0 drivers/usb/core/message.c:2170
usb_generic_driver_probe+0x13c/0x300 drivers/usb/core/generic.c:238
usb_probe_device+0x309/0x570 drivers/usb/core/driver.c:293
really_probe+0x67d/0x1510 drivers/base/dd.c:596
__driver_probe_device+0x3e9/0x530 drivers/base/dd.c:751
driver_probe_device drivers/base/dd.c:781 [inline]
__device_attach_driver+0x79f/0x1120 drivers/base/dd.c:898
bus_for_each_drv+0x2d6/0x3f0 drivers/base/bus.c:427
__device_attach+0x593/0x8e0 drivers/base/dd.c:969
device_initial_probe+0x4a/0x60 drivers/base/dd.c:1016
bus_probe_device+0x17b/0x3e0 drivers/base/bus.c:487
device_add+0x1d3e/0x2400 drivers/base/core.c:3394
usb_new_device+0x1b8e/0x2950 drivers/usb/core/hub.c:2563
hub_port_connect drivers/usb/core/hub.c:5353 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5497 [inline]
port_event drivers/usb/core/hub.c:5643 [inline]
hub_event+0x5ad2/0x8910 drivers/usb/core/hub.c:5725
process_one_work+0xdb9/0x1820 kernel/workqueue.c:2298
worker_thread+0x10bc/0x21f0 kernel/workqueue.c:2445
kthread+0x721/0x850 kernel/kthread.c:327
ret_from_fork+0x1f/0x30

Uninit was stored to memory at:
kmemdup+0x107/0x140 mm/util.c:130
__usbnet_write_cmd drivers/net/usb/usbnet.c:2039 [inline]
usbnet_write_cmd+0x1a0/0x480 drivers/net/usb/usbnet.c:2088
mcs7830_set_reg drivers/net/usb/mcs7830.c:117 [inline]
mcs7830_hif_set_mac_address drivers/net/usb/mcs7830.c:138 [inline]
mcs7830_apply_base_config+0xd5/0x8a0 drivers/net/usb/mcs7830.c:387
mcs7830_bind+0x753/0xb70 drivers/net/usb/mcs7830.c:492
usbnet_probe+0x1284/0x4140 drivers/net/usb/usbnet.c:1747
usb_probe_interface+0xf19/0x1600 drivers/usb/core/driver.c:396
really_probe+0x67d/0x1510 drivers/base/dd.c:596
__driver_probe_device+0x3e9/0x530 drivers/base/dd.c:751
driver_probe_device drivers/base/dd.c:781 [inline]
__device_attach_driver+0x79f/0x1120 drivers/base/dd.c:898
bus_for_each_drv+0x2d6/0x3f0 drivers/base/bus.c:427
__device_attach+0x593/0x8e0 drivers/base/dd.c:969
device_initial_probe+0x4a/0x60 drivers/base/dd.c:1016
bus_probe_device+0x17b/0x3e0 drivers/base/bus.c:487
device_add+0x1d3e/0x2400 drivers/base/core.c:3394
usb_set_configuration+0x37e9/0x3ed0 drivers/usb/core/message.c:2170
usb_generic_driver_probe+0x13c/0x300 drivers/usb/core/generic.c:238
usb_probe_device+0x309/0x570 drivers/usb/core/driver.c:293
really_probe+0x67d/0x1510 drivers/base/dd.c:596
__driver_probe_device+0x3e9/0x530 drivers/base/dd.c:751
driver_probe_device drivers/base/dd.c:781 [inline]
__device_attach_driver+0x79f/0x1120 drivers/base/dd.c:898
bus_for_each_drv+0x2d6/0x3f0 drivers/base/bus.c:427
__device_attach+0x593/0x8e0 drivers/base/dd.c:969
device_initial_probe+0x4a/0x60 drivers/base/dd.c:1016
bus_probe_device+0x17b/0x3e0 drivers/base/bus.c:487
device_add+0x1d3e/0x2400 drivers/base/core.c:3394
usb_new_device+0x1b8e/0x2950 drivers/usb/core/hub.c:2563
hub_port_connect drivers/usb/core/hub.c:5353 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5497 [inline]
port_event drivers/usb/core/hub.c:5643 [inline]
hub_event+0x5ad2/0x8910 drivers/usb/core/hub.c:5725
process_one_work+0xdb9/0x1820 kernel/workqueue.c:2298
worker_thread+0x10bc/0x21f0 kernel/workqueue.c:2445
kthread+0x721/0x850 kernel/kthread.c:327
ret_from_fork+0x1f/0x30

Uninit was stored to memory at:
__dev_addr_set include/linux/netdevice.h:4655 [inline]
eth_hw_addr_set include/linux/etherdevice.h:319 [inline]
mcs7830_bind+0x230/0xb70 drivers/net/usb/mcs7830.c:488
usbnet_probe+0x1284/0x4140 drivers/net/usb/usbnet.c:1747
usb_probe_interface+0xf19/0x1600 drivers/usb/core/driver.c:396
really_probe+0x67d/0x1510 drivers/base/dd.c:596
__driver_probe_device+0x3e9/0x530 drivers/base/dd.c:751
driver_probe_device drivers/base/dd.c:781 [inline]
__device_attach_driver+0x79f/0x1120 drivers/base/dd.c:898
bus_for_each_drv+0x2d6/0x3f0 drivers/base/bus.c:427
__device_attach+0x593/0x8e0 drivers/base/dd.c:969
device_initial_probe+0x4a/0x60 drivers/base/dd.c:1016
bus_probe_device+0x17b/0x3e0 drivers/base/bus.c:487
device_add+0x1d3e/0x2400 drivers/base/core.c:3394
usb_set_configuration+0x37e9/0x3ed0 drivers/usb/core/message.c:2170
usb_generic_driver_probe+0x13c/0x300 drivers/usb/core/generic.c:238
usb_probe_device+0x309/0x570 drivers/usb/core/driver.c:293
really_probe+0x67d/0x1510 drivers/base/dd.c:596
__driver_probe_device+0x3e9/0x530 drivers/base/dd.c:751
driver_probe_device drivers/base/dd.c:781 [inline]
__device_attach_driver+0x79f/0x1120 drivers/base/dd.c:898
bus_for_each_drv+0x2d6/0x3f0 drivers/base/bus.c:427
__device_attach+0x593/0x8e0 drivers/base/dd.c:969
device_initial_probe+0x4a/0x60 drivers/base/dd.c:1016
bus_probe_device+0x17b/0x3e0 drivers/base/bus.c:487
device_add+0x1d3e/0x2400 drivers/base/core.c:3394
usb_new_device+0x1b8e/0x2950 drivers/usb/core/hub.c:2563
hub_port_connect drivers/usb/core/hub.c:5353 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5497 [inline]
port_event drivers/usb/core/hub.c:5643 [inline]
hub_event+0x5ad2/0x8910 drivers/usb/core/hub.c:5725
process_one_work+0xdb9/0x1820 kernel/workqueue.c:2298
worker_thread+0x10bc/0x21f0 kernel/workqueue.c:2445
kthread+0x721/0x850 kernel/kthread.c:327
ret_from_fork+0x1f/0x30

Local variable addr created at:
mcs7830_bind+0x9b/0xb70 drivers/net/usb/mcs7830.c:476
usbnet_probe+0x1284/0x4140 drivers/net/usb/usbnet.c:1747

Bytes 0-3 of 6 are uninitialized
Memory access of size 6 starts at ffff88811d26f2b0

CPU: 1 PID: 19 Comm: kworker/1:0 Not tainted 5.16.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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:
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syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches

[Pavel Skripkin]

On 1/5/22 21:28, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 81c325bbf94e kmsan: hooks: do not check memory in kmsan_in..
> git tree: https://github.com/google/kmsan.git master
> console output: https://syzkaller.appspot.com/x/log.txt?x=14a07163b00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=2d8b9a11641dc9aa
> dashboard link: https://syzkaller.appspot.com/bug?extid=003c0a286b9af5412510
> compiler: clang version 14.0.0 (/usr/local/google/src/llvm-git-monorepo 2b554920f11c8b763cd9ed9003f4e19b919b8e1f), GNU ld (GNU Binutils for Debian) 2.35.2
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=100165dbb00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10c97e77b00000
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+003c0a...@syzkaller.appspotmail.com
>

Heh, I think, more reports like this will appear soon. Syzbot learned
how to tweak usb read functions return values, I guess?

#syz test: https://github.com/google/kmsan.git master



With regards,
Pavel Skripkin

[syzbot]

Hello,

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

Reported-and-tested-by: syzbot+003c0a...@syzkaller.appspotmail.com

Tested on:

commit: 81c325bb kmsan: hooks: do not check memory in kmsan_in..

git tree: https://github.com/google/kmsan.git master

kernel config: https://syzkaller.appspot.com/x/.config?x=2d8b9a11641dc9aa
dashboard link: https://syzkaller.appspot.com/bug?extid=003c0a286b9af5412510
compiler: clang version 14.0.0 (/usr/local/google/src/llvm-git-monorepo 2b554920f11c8b763cd9ed9003f4e19b919b8e1f), GNU ld (GNU Binutils for Debian) 2.35.2

patch: https://syzkaller.appspot.com/x/patch.diff?x=11dd4b71b00000

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

[Alexander Potapenko]

This has been possible long ago. I think these new reports are related
to fresh KMSAN changes (and also the fact KMSAN was broken for a while
last year, and is now catching up).

> #syz test: https://github.com/google/kmsan.git master
>
>
>
> With regards,
> Pavel Skripkin

--
Alexander Potapenko
Software Engineer

Google Germany GmbH
Erika-Mann-Straße, 33
80636 München

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