media: gspca/sq905.c: fix uninitialized variable

Hans Verkuil · gregkh · commit ff6c9140bc91 · 2021-05-22T10:40:17.000+02:00
[ Upstream commit eaaea4681984c79d2b2b160387b297477f0c1aab ]

act_len can be uninitialized if usb_bulk_msg() returns an error.
Set it to 0 to avoid a KMSAN error.

Signed-off-by: Hans Verkuil &lt;hverkuil-cisco@xs4all.nl&gt;
Reported-by: syzbot+a4e309017a5f3a24c7b3@syzkaller.appspotmail.com
Signed-off-by: Mauro Carvalho Chehab &lt;mchehab+huawei@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
diff --git a/drivers/media/usb/gspca/sq905.c b/drivers/media/usb/gspca/sq905.c
@@ -172,7 +172,7 @@ static int
 sq905_read_data(struct gspca_dev *gspca_dev, u8 *data, int size, int need_lock)
 {
 	int ret;
-	int act_len;
+	int act_len = 0;
 
 	gspca_dev->usb_buf[0] = '\0';
 	if (need_lock)

Original file line number	Diff line number	Diff line change
`@@ -172,7 +172,7 @@ static int`
`172`	`172`	`sq905_read_data(struct gspca_dev gspca_dev, u8 data, int size, int need_lock)`
`173`	`173`	`{`
`174`	`174`	`int ret;`
`175`		`- int act_len;`
	`175`	`+ int act_len = 0;`
`176`	`176`
`177`	`177`	`gspca_dev->usb_buf[0] = '\0';`
`178`	`178`	`if (need_lock)`