* [PATCH] usb: idmouse: fix an uninit-value in idmouse_open
@ 2022-09-22 13:48 Dongliang Mu
0 siblings, 0 replies; only message in thread
From: Dongliang Mu @ 2022-09-22 13:48 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Dongliang Mu, syzbot+79832d33eb89fb3cd092, linux-usb, linux-kernel
From: Dongliang Mu <mudongliangabcd@gmail.com>
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>
---
drivers/usb/misc/idmouse.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/misc/idmouse.c b/drivers/usb/misc/idmouse.c
index e9437a176518..ea39243efee3 100644
--- a/drivers/usb/misc/idmouse.c
+++ b/drivers/usb/misc/idmouse.c
@@ -177,10 +177,6 @@ static int idmouse_create_image(struct usb_idmouse *dev)
bytes_read += bulk_read;
}
- /* reset the device */
-reset:
- ftip_command(dev, FTIP_RELEASE, 0, 0);
-
/* check for valid image */
/* right border should be black (0x00) */
for (bytes_read = sizeof(HEADER)-1 + WIDTH-1; bytes_read < IMGSIZE; bytes_read += WIDTH)
@@ -192,6 +188,10 @@ static int idmouse_create_image(struct usb_idmouse *dev)
if (dev->bulk_in_buffer[bytes_read] != 0xFF)
return -EAGAIN;
+ /* reset the device */
+reset:
+ ftip_command(dev, FTIP_RELEASE, 0, 0);
+
/* should be IMGSIZE == 65040 */
dev_dbg(&dev->interface->dev, "read %d bytes fingerprint data\n",
bytes_read);
--
2.25.1
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2022-09-22 13:48 [PATCH] usb: idmouse: fix an uninit-value in idmouse_open Dongliang Mu
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