From 3208e455284bf6167434ed1d85f0fbb8f3564ab2 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Mon, 13 Mar 2017 09:53:58 -0300 Subject: [PATCH] cx231xx-audio: fix NULL-deref at probe commit 65f921647f4c89a2068478c89691f39b309b58f7 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: e0d3bafd0258 ("V4L/DVB (10954): Add cx231xx USB driver") Cc: Sri Deevi Signed-off-by: Johan Hovold Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- drivers/media/usb/cx231xx/cx231xx-audio.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/media/usb/cx231xx/cx231xx-audio.c b/drivers/media/usb/cx231xx/cx231xx-audio.c index 46e90ac89d66..10d8a08e36e6 100644 --- a/drivers/media/usb/cx231xx/cx231xx-audio.c +++ b/drivers/media/usb/cx231xx/cx231xx-audio.c @@ -698,6 +698,11 @@ static int cx231xx_audio_init(struct cx231xx *dev) hs_config_info[0].interface_info. audio_index + 1]; + if (uif->altsetting[0].desc.bNumEndpoints < isoc_pipe + 1) { + err = -ENODEV; + goto err_free_card; + } + adev->end_point_addr = uif->altsetting[0].endpoint[isoc_pipe].desc. bEndpointAddress; @@ -713,8 +718,14 @@ static int cx231xx_audio_init(struct cx231xx *dev) } for (i = 0; i < adev->num_alt; i++) { - u16 tmp = - le16_to_cpu(uif->altsetting[i].endpoint[isoc_pipe].desc. + u16 tmp; + + if (uif->altsetting[i].desc.bNumEndpoints < isoc_pipe + 1) { + err = -ENODEV; + goto err_free_pkt_size; + } + + tmp = le16_to_cpu(uif->altsetting[i].endpoint[isoc_pipe].desc. wMaxPacketSize); adev->alt_max_pkt_size[i] = (tmp & 0x07ff) * (((tmp & 0x1800) >> 11) + 1); @@ -725,6 +736,8 @@ static int cx231xx_audio_init(struct cx231xx *dev) return 0; +err_free_pkt_size: + kfree(adev->alt_max_pkt_size); err_free_card: snd_card_free(card); -- 2.34.1