usb: idmouse: fix an uninit-value in idmouse_open
authorDongliang Mu <mudongliangabcd@gmail.com>
Thu, 22 Sep 2022 13:48:44 +0000 (21:48 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 27 Sep 2022 08:37:09 +0000 (10:37 +0200)
commitbce2b0539933e485d22d6f6f076c0fcd6f185c4c
tree476a918550d318fc8ba8e904adeb8373f4fcdd6c
parent411c4597df7dcc60b7aae83761618c94a60ded3f
usb: idmouse: fix an uninit-value in idmouse_open

In idmouse_create_image, if any ftip_command fails, it will
go to the reset label. However, this leads to the data in
bulk_in_buffer[HEADER..IMGSIZE] uninitialized. And the check
for valid image incurs an uninitialized dereference.

Fix this by moving the check before reset label since this
check only be valid if the data after bulk_in_buffer[HEADER]
has concrete data.

Note that this is found by KMSAN, so only kernel compilation
is tested.

Reported-by: syzbot+79832d33eb89fb3cd092@syzkaller.appspotmail.com
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Link: https://lore.kernel.org/r/20220922134847.1101921-1-dzm91@hust.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/misc/idmouse.c