* [PATCH] Media: video: uvc: integer overflow in uvc_ioctl_ctrl_map()
@ 2011-11-29 21:32 Haogang Chen
2011-11-30 1:22 ` Laurent Pinchart
0 siblings, 1 reply; 6+ messages in thread
From: Haogang Chen @ 2011-11-29 21:32 UTC (permalink / raw)
To: laurent.pinchart, mchehab; +Cc: linux-media, linux-kernel, Haogang Chen
There is a potential integer overflow in uvc_ioctl_ctrl_map(). When a
large xmap->menu_count is passed from the userspace, the subsequent call
to kmalloc() will allocate a buffer smaller than expected.
map->menu_count and map->menu_info would later be used in a loop (e.g.
in uvc_query_v4l2_ctrl), which leads to out-of-bound access.
The patch checks the ioctl argument and returns -EINVAL for zero or too
large values in xmap->menu_count.
Signed-off-by: Haogang Chen <haogangchen@gmail.com>
---
drivers/media/video/uvc/uvc_v4l2.c | 6 ++++++
1 files changed, 6 insertions(+), 0 deletions(-)
diff --git a/drivers/media/video/uvc/uvc_v4l2.c b/drivers/media/video/uvc/uvc_v4l2.c
index dadf11f..9a180d6 100644
--- a/drivers/media/video/uvc/uvc_v4l2.c
+++ b/drivers/media/video/uvc/uvc_v4l2.c
@@ -58,6 +58,12 @@ static int uvc_ioctl_ctrl_map(struct uvc_video_chain *chain,
break;
case V4L2_CTRL_TYPE_MENU:
+ if (xmap->menu_count == 0 ||
+ xmap->menu_count > INT_MAX / sizeof(*map->menu_info)) {
+ kfree(map);
+ return -EINVAL;
+ }
+
size = xmap->menu_count * sizeof(*map->menu_info);
map->menu_info = kmalloc(size, GFP_KERNEL);
if (map->menu_info == NULL) {
--
1.7.5.4
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] Media: video: uvc: integer overflow in uvc_ioctl_ctrl_map()
2011-11-29 21:32 [PATCH] Media: video: uvc: integer overflow in uvc_ioctl_ctrl_map() Haogang Chen
@ 2011-11-30 1:22 ` Laurent Pinchart
2011-11-30 2:28 ` Haogang Chen
2011-12-11 10:22 ` Mauro Carvalho Chehab
0 siblings, 2 replies; 6+ messages in thread
From: Laurent Pinchart @ 2011-11-30 1:22 UTC (permalink / raw)
To: Haogang Chen; +Cc: mchehab, linux-media, linux-kernel
Hi Haogang,
On Tuesday 29 November 2011 22:32:25 Haogang Chen wrote:
> There is a potential integer overflow in uvc_ioctl_ctrl_map(). When a
> large xmap->menu_count is passed from the userspace, the subsequent call
> to kmalloc() will allocate a buffer smaller than expected.
> map->menu_count and map->menu_info would later be used in a loop (e.g.
> in uvc_query_v4l2_ctrl), which leads to out-of-bound access.
>
> The patch checks the ioctl argument and returns -EINVAL for zero or too
> large values in xmap->menu_count.
Thanks for the patch.
> Signed-off-by: Haogang Chen <haogangchen@gmail.com>
> ---
> drivers/media/video/uvc/uvc_v4l2.c | 6 ++++++
> 1 files changed, 6 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/media/video/uvc/uvc_v4l2.c
> b/drivers/media/video/uvc/uvc_v4l2.c index dadf11f..9a180d6 100644
> --- a/drivers/media/video/uvc/uvc_v4l2.c
> +++ b/drivers/media/video/uvc/uvc_v4l2.c
> @@ -58,6 +58,12 @@ static int uvc_ioctl_ctrl_map(struct uvc_video_chain
> *chain, break;
>
> case V4L2_CTRL_TYPE_MENU:
> + if (xmap->menu_count == 0 ||
> + xmap->menu_count > INT_MAX / sizeof(*map->menu_info)) {
I'd like to prevent excessive memory consumption by limiting the number of
menu entries, similarly to how the driver limits the number of mappings.
Defining UVC_MAX_CONTROL_MENU_ENTRIES to 32 in uvcvideo.h should be a
reasonable value.
> + kfree(map);
> + return -EINVAL;
I'd rather do
ret = -EINVAL;
goto done;
to centralize error handling.
If you're fine with both changes I can modify the patch, there's no need to
resubmit.
> + }
> +
> size = xmap->menu_count * sizeof(*map->menu_info);
> map->menu_info = kmalloc(size, GFP_KERNEL);
> if (map->menu_info == NULL) {
--
Regards,
Laurent Pinchart
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] Media: video: uvc: integer overflow in uvc_ioctl_ctrl_map()
2011-11-30 1:22 ` Laurent Pinchart
@ 2011-11-30 2:28 ` Haogang Chen
2011-11-30 9:14 ` Laurent Pinchart
2011-12-11 10:22 ` Mauro Carvalho Chehab
1 sibling, 1 reply; 6+ messages in thread
From: Haogang Chen @ 2011-11-30 2:28 UTC (permalink / raw)
To: Laurent Pinchart; +Cc: mchehab, linux-media, linux-kernel
The hard limit sounds good to me. But if you want to centralize error
handling, please make sure that "goto done" only frees map, but not
map->menu_info in that case.
- Haogang
On Tue, Nov 29, 2011 at 8:22 PM, Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
> Hi Haogang,
>
> On Tuesday 29 November 2011 22:32:25 Haogang Chen wrote:
>> There is a potential integer overflow in uvc_ioctl_ctrl_map(). When a
>> large xmap->menu_count is passed from the userspace, the subsequent call
>> to kmalloc() will allocate a buffer smaller than expected.
>> map->menu_count and map->menu_info would later be used in a loop (e.g.
>> in uvc_query_v4l2_ctrl), which leads to out-of-bound access.
>>
>> The patch checks the ioctl argument and returns -EINVAL for zero or too
>> large values in xmap->menu_count.
>
> Thanks for the patch.
>
>> Signed-off-by: Haogang Chen <haogangchen@gmail.com>
>> ---
>> drivers/media/video/uvc/uvc_v4l2.c | 6 ++++++
>> 1 files changed, 6 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/media/video/uvc/uvc_v4l2.c
>> b/drivers/media/video/uvc/uvc_v4l2.c index dadf11f..9a180d6 100644
>> --- a/drivers/media/video/uvc/uvc_v4l2.c
>> +++ b/drivers/media/video/uvc/uvc_v4l2.c
>> @@ -58,6 +58,12 @@ static int uvc_ioctl_ctrl_map(struct uvc_video_chain
>> *chain, break;
>>
>> case V4L2_CTRL_TYPE_MENU:
>> + if (xmap->menu_count == 0 ||
>> + xmap->menu_count > INT_MAX / sizeof(*map->menu_info)) {
>
> I'd like to prevent excessive memory consumption by limiting the number of
> menu entries, similarly to how the driver limits the number of mappings.
> Defining UVC_MAX_CONTROL_MENU_ENTRIES to 32 in uvcvideo.h should be a
> reasonable value.
>
>> + kfree(map);
>> + return -EINVAL;
>
> I'd rather do
>
> ret = -EINVAL;
> goto done;
>
> to centralize error handling.
>
> If you're fine with both changes I can modify the patch, there's no need to
> resubmit.
>
>> + }
>> +
>> size = xmap->menu_count * sizeof(*map->menu_info);
>> map->menu_info = kmalloc(size, GFP_KERNEL);
>> if (map->menu_info == NULL) {
>
> --
> Regards,
>
> Laurent Pinchart
>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] Media: video: uvc: integer overflow in uvc_ioctl_ctrl_map()
2011-11-30 1:22 ` Laurent Pinchart
2011-11-30 2:28 ` Haogang Chen
@ 2011-12-11 10:22 ` Mauro Carvalho Chehab
2011-12-11 10:31 ` Laurent Pinchart
1 sibling, 1 reply; 6+ messages in thread
From: Mauro Carvalho Chehab @ 2011-12-11 10:22 UTC (permalink / raw)
To: Laurent Pinchart; +Cc: Haogang Chen, linux-media, linux-kernel
On 29-11-2011 23:22, Laurent Pinchart wrote:
> Hi Haogang,
>
> On Tuesday 29 November 2011 22:32:25 Haogang Chen wrote:
>> There is a potential integer overflow in uvc_ioctl_ctrl_map(). When a
>> large xmap->menu_count is passed from the userspace, the subsequent call
>> to kmalloc() will allocate a buffer smaller than expected.
>> map->menu_count and map->menu_info would later be used in a loop (e.g.
>> in uvc_query_v4l2_ctrl), which leads to out-of-bound access.
>>
>> The patch checks the ioctl argument and returns -EINVAL for zero or too
>> large values in xmap->menu_count.
>
> Thanks for the patch.
I'm assuming that either one of you will re-send the patches with the
pointed changes, so, I'm marking this one with "changes requested" at
patchwork.
>
>> Signed-off-by: Haogang Chen<haogangchen@gmail.com>
>> ---
>> drivers/media/video/uvc/uvc_v4l2.c | 6 ++++++
>> 1 files changed, 6 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/media/video/uvc/uvc_v4l2.c
>> b/drivers/media/video/uvc/uvc_v4l2.c index dadf11f..9a180d6 100644
>> --- a/drivers/media/video/uvc/uvc_v4l2.c
>> +++ b/drivers/media/video/uvc/uvc_v4l2.c
>> @@ -58,6 +58,12 @@ static int uvc_ioctl_ctrl_map(struct uvc_video_chain
>> *chain, break;
>>
>> case V4L2_CTRL_TYPE_MENU:
>> + if (xmap->menu_count == 0 ||
>> + xmap->menu_count> INT_MAX / sizeof(*map->menu_info)) {
>
> I'd like to prevent excessive memory consumption by limiting the number of
> menu entries, similarly to how the driver limits the number of mappings.
> Defining UVC_MAX_CONTROL_MENU_ENTRIES to 32 in uvcvideo.h should be a
> reasonable value.
>
>> + kfree(map);
>> + return -EINVAL;
>
> I'd rather do
>
> ret = -EINVAL;
> goto done;
>
> to centralize error handling.
>
> If you're fine with both changes I can modify the patch, there's no need to
> resubmit.
>
>> + }
>> +
>> size = xmap->menu_count * sizeof(*map->menu_info);
>> map->menu_info = kmalloc(size, GFP_KERNEL);
>> if (map->menu_info == NULL) {
>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] Media: video: uvc: integer overflow in uvc_ioctl_ctrl_map()
2011-12-11 10:22 ` Mauro Carvalho Chehab
@ 2011-12-11 10:31 ` Laurent Pinchart
0 siblings, 0 replies; 6+ messages in thread
From: Laurent Pinchart @ 2011-12-11 10:31 UTC (permalink / raw)
To: Mauro Carvalho Chehab; +Cc: Haogang Chen, linux-media, linux-kernel
Hi Mauro,
On Sunday 11 December 2011 11:22:29 Mauro Carvalho Chehab wrote:
> On 29-11-2011 23:22, Laurent Pinchart wrote:
> > Hi Haogang,
> >
> > On Tuesday 29 November 2011 22:32:25 Haogang Chen wrote:
> >> There is a potential integer overflow in uvc_ioctl_ctrl_map(). When a
> >> large xmap->menu_count is passed from the userspace, the subsequent call
> >> to kmalloc() will allocate a buffer smaller than expected.
> >> map->menu_count and map->menu_info would later be used in a loop (e.g.
> >> in uvc_query_v4l2_ctrl), which leads to out-of-bound access.
> >>
> >> The patch checks the ioctl argument and returns -EINVAL for zero or too
> >> large values in xmap->menu_count.
> >
> > Thanks for the patch.
>
> I'm assuming that either one of you will re-send the patches with the
> pointed changes, so, I'm marking this one with "changes requested" at
> patchwork.
The modified patch is included in my latest pull request.
I had forgotten to CC stable@kernel.org in the commit message. I've updated
the uvcvideo-next branch, but have you already pulled from it ? If so, could
you add Cc: stable@kernel.org to the patch, or should I send a v2 for the pull
request ?
> >> Signed-off-by: Haogang Chen<haogangchen@gmail.com>
> >> ---
> >>
> >> drivers/media/video/uvc/uvc_v4l2.c | 6 ++++++
> >> 1 files changed, 6 insertions(+), 0 deletions(-)
> >>
> >> diff --git a/drivers/media/video/uvc/uvc_v4l2.c
> >> b/drivers/media/video/uvc/uvc_v4l2.c index dadf11f..9a180d6 100644
> >> --- a/drivers/media/video/uvc/uvc_v4l2.c
> >> +++ b/drivers/media/video/uvc/uvc_v4l2.c
> >> @@ -58,6 +58,12 @@ static int uvc_ioctl_ctrl_map(struct uvc_video_chain
> >> *chain, break;
> >>
> >> case V4L2_CTRL_TYPE_MENU:
> >> + if (xmap->menu_count == 0 ||
> >> + xmap->menu_count> INT_MAX / sizeof(*map->menu_info)) {
> >
> > I'd like to prevent excessive memory consumption by limiting the number
> > of menu entries, similarly to how the driver limits the number of
> > mappings. Defining UVC_MAX_CONTROL_MENU_ENTRIES to 32 in uvcvideo.h
> > should be a reasonable value.
> >
> >> + kfree(map);
> >> + return -EINVAL;
> >
> > I'd rather do
> >
> > ret = -EINVAL;
> > goto done;
> >
> > to centralize error handling.
> >
> > If you're fine with both changes I can modify the patch, there's no need
> > to resubmit.
> >
> >> + }
> >> +
> >>
> >> size = xmap->menu_count * sizeof(*map->menu_info);
> >> map->menu_info = kmalloc(size, GFP_KERNEL);
> >> if (map->menu_info == NULL) {
--
Regards,
Laurent Pinchart
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2011-12-11 10:31 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2011-11-29 21:32 [PATCH] Media: video: uvc: integer overflow in uvc_ioctl_ctrl_map() Haogang Chen
2011-11-30 1:22 ` Laurent Pinchart
2011-11-30 2:28 ` Haogang Chen
2011-11-30 9:14 ` Laurent Pinchart
2011-12-11 10:22 ` Mauro Carvalho Chehab
2011-12-11 10:31 ` Laurent Pinchart
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