From cc63d977beaa8a317f99ac6d7c843965007bd2c1 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Mon, 13 Mar 2017 09:53:55 -0300 Subject: usbvision: fix NULL-deref at probe commit eacb975b48272f54532b62f515a3cf7eefa35123 upstream. Make sure to check the number of endpoints to avoid dereferencing a NULL-pointer or accessing memory beyond the endpoint array should a malicious device lack the expected endpoints. Fixes: 2a9f8b5d25be ("V4L/DVB (5206): Usbvision: set alternate interface modification") Cc: Thierry MERLE Signed-off-by: Johan Hovold Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab [bwh: Backported to 3.2: adjust filename] Signed-off-by: Ben Hutchings --- drivers/media/video/usbvision/usbvision-video.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/media/video/usbvision/usbvision-video.c b/drivers/media/video/usbvision/usbvision-video.c index 8f7408116362..b522f838603e 100644 --- a/drivers/media/video/usbvision/usbvision-video.c +++ b/drivers/media/video/usbvision/usbvision-video.c @@ -1564,7 +1564,14 @@ static int __devinit usbvision_probe(struct usb_interface *intf, } for (i = 0; i < usbvision->num_alt; i++) { - u16 tmp = le16_to_cpu(uif->altsetting[i].endpoint[1].desc. + u16 tmp; + + if (uif->altsetting[i].desc.bNumEndpoints < 2) { + ret = -ENODEV; + goto err_pkt; + } + + tmp = le16_to_cpu(uif->altsetting[i].endpoint[1].desc. wMaxPacketSize); usbvision->alt_max_pkt_size[i] = (tmp & 0x07ff) * (((tmp & 0x1800) >> 11) + 1); -- cgit v1.2.3