stable inclusion
from linux-4.19.226
commit e0b2cd310d0859907a9a7b4e4ef9a5bcce9d3d6d

--------------------------------

[ Upstream commit d668769e ]

Syzbot reported uninit value in mcs7830_bind(). The problem was in
missing validation check for bytes read via usbnet_read_cmd().

usbnet_read_cmd() internally calls usb_control_msg(), that returns
number of bytes read. Code should validate that requested number of bytes
was actually read.

So, this patch adds missing size validation check inside
mcs7830_get_reg() to prevent uninit value bugs

Reported-and-tested-by: syzbot+003c0a286b9af5412510@syzkaller.appspotmail.com
Fixes: 2a36d708 ("USB: driver for mcs7830 (aka DeLOCK) USB ethernet adapter")
Signed-off-by: NPavel Skripkin <paskripkin@gmail.com>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20220106225716.7425-1-paskripkin@gmail.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYongqiang Liu <liuyongqiang13@huawei.com>
Signed-off-by: NLaibin Qiu <qiulaibin@huawei.com>
Signed-off-by: NYongqiang Liu <liuyongqiang13@huawei.com>