lkml.org 
[lkml]   [2022]   [Oct]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.14 202/210] usb: idmouse: fix an uninit-value in idmouse_open
Date
From: Dongliang Mu <mudongliangabcd@gmail.com>

[ Upstream commit bce2b0539933e485d22d6f6f076c0fcd6f185c4c ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 01ef2551be46..974b8d0621bd 100644
--- a/drivers/usb/misc/idmouse.c
+++ b/drivers/usb/misc/idmouse.c
@@ -182,10 +182,6 @@ 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)
@@ -197,6 +193,10 @@ 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);
--
2.35.1


\
 
 \ /
  Last update: 2022-10-24 21:46    [W:0.658 / U:0.020 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site