[PATCH 5.6 19/23] media: ov519: add missing endpoint sanity checks

Greg Kroah-Hartman
2020-03-31T09:23:45Z

From: Johan Hovold <johan@kernel.org>

commit 998912346c0da53a6dbb71fab3a138586b596b30 upstream.

Make sure to check that we have at least one endpoint before accessing
the endpoint array to avoid dereferencing a NULL-pointer on stream
start.

Note that these sanity checks are not redundant as the driver is mixing
looking up altsettings by index and by number, which need not coincide.

Fixes: 1876bb923c98 ("V4L/DVB (12079): gspca_ov519: add support for the ov511 bridge")
Fixes: b282d87332f5 ("V4L/DVB (12080): gspca_ov519: Fix ov518+ with OV7620AE (Trust spacecam 320)")
Cc: stable <stable@vger.kernel.org> # 2.6.31
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/media/usb/gspca/ov519.c | 10 ++++++++++
1 file changed, 10 insertions(+)

--- a/drivers/media/usb/gspca/ov519.c
+++ b/drivers/media/usb/gspca/ov519.c
@@ -3477,6 +3477,11 @@ static void ov511_mode_init_regs(struct
return;
}

+ if (alt->desc.bNumEndpoints < 1) {
+ sd->gspca_dev.usb_err = -ENODEV;
+ return;
+ }
+
packet_size = le16_to_cpu(alt->endpoint[0].desc.wMaxPacketSize);
reg_w(sd, R51x_FIFO_PSIZE, packet_size >> 5);

@@ -3603,6 +3608,11 @@ static void ov518_mode_init_regs(struct
return;
}

+ if (alt->desc.bNumEndpoints < 1) {
+ sd->gspca_dev.usb_err = -ENODEV;
+ return;
+ }
+
packet_size = le16_to_cpu(alt->endpoint[0].desc.wMaxPacketSize);
ov518_reg_w32(sd, R51x_FIFO_PSIZE, packet_size & ~7, 2);