[PATCH 3.16 037/134] [media] cx231xx-audio: fix NULL-deref at probe
From: Ben Hutchings <hidden>
Date: 2017-08-18 13:53:15
Also in:
lkml
3.16.47-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Johan Hovold <johan@kernel.org>
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 <redacted>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Hans Verkuil <redacted>
Signed-off-by: Mauro Carvalho Chehab <redacted>
Signed-off-by: Ben Hutchings <redacted>
---
drivers/media/usb/cx231xx/cx231xx-audio.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
--- a/drivers/media/usb/cx231xx/cx231xx-audio.c
+++ b/drivers/media/usb/cx231xx/cx231xx-audio.c@@ -699,6 +699,11 @@ static int cx231xx_audio_init(struct cx2 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;
@@ -714,8 +719,14 @@ static int cx231xx_audio_init(struct cx2 } 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 cx2 return 0; +err_free_pkt_size: + kfree(adev->alt_max_pkt_size); err_free_card: snd_card_free(card);