Re: [PATCH v2] Fixing arbitrary kernel leak in case FBIOGETCMAP_SPARC in sbusfb_ioctl_helper().

[Bartlomiej Zolnierkiewicz]

On Sunday, February 04, 2018 09:18:03 AM Peter Malone wrote:
> Hi folks,

Hi,

> CVE-2018-6412 has been created for this. Is it possible for you to add
> a note indicating the CVE number when merging the patch?
> 
> I received the CVE number after the patch was created and ack'd, which
> is why I didn't include it in the commit message.

I queued the patch (with Mathieu's ACK and CVE number added to the patch
description) for v4.16, thanks.

> On Wed, Jan 31, 2018 at 10:49 AM, Mathieu Malaterre  wrote:
> > Hi Peter,
> >
> > On Wed, Jan 31, 2018 at 3:57 PM, Peter Malone  
> > wrote:
> >> Fixing arbitrary kernel leak in case FBIOGETCMAP_SPARC in
> >> sbusfb_ioctl_helper().
> >>
> >> 'index' is defined as an int in sbusfb_ioctl_helper().
> >> We retrieve this from the user:
> >> if (get_user(index, >index) ||
> >> __get_user(count, >count) ||
> >> __get_user(ured, >red) ||
> >> __get_user(ugreen, >green) ||
> >> __get_user(ublue, >blue))
> >>return -EFAULT;
> >>
> >> and then we use 'index' in the following way:
> >> red = cmap->red[index + i] >> 8;
> >> green = cmap->green[index + i] >> 8;
> >> blue = cmap->blue[index + i] >> 8;
> >>
> >> This is a classic information leak vulnerability. 'index' should be
> >> an unsigned int, given its usage above.
> >>
> >> This patch is straight-forward; it changes 'index' to unsigned int
> >> in two switch-cases: FBIOGETCMAP_SPARC && FBIOPUTCMAP_SPARC.
> >>
> >> Signed-off-by: Peter Malone 
> >> ---
> >
> > much better :)
> >
> >> v2: fixed formatting
> >>
> >>  drivers/video/fbdev/sbuslib.c | 4 ++--
> >>  1 file changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/video/fbdev/sbuslib.c b/drivers/video/fbdev/sbuslib.c
> >> index af6fc97f4ba4..a436d44f1b7f 100644
> >> --- a/drivers/video/fbdev/sbuslib.c
> >> +++ b/drivers/video/fbdev/sbuslib.c
> >> @@ -122,7 +122,7 @@ int sbusfb_ioctl_helper(unsigned long cmd, unsigned 
> >> long arg,
> >> unsigned char __user *ured;
> >> unsigned char __user *ugreen;
> >> unsigned char __user *ublue;
> >> -   int index, count, i;
> >> +   unsigned int index, count, i;
> >>
> >> if (get_user(index, >index) ||
> >> __get_user(count, >count) ||
> >> @@ -161,7 +161,7 @@ int sbusfb_ioctl_helper(unsigned long cmd, unsigned 
> >> long arg,
> >> unsigned char __user *ugreen;
> >> unsigned char __user *ublue;
> >> struct fb_cmap *cmap = >cmap;
> >> -   int index, count, i;
> >> +   unsigned int index, count, i;
> >> u8 red, green, blue;
> >>
> >> if (get_user(index, >index) ||
> >> --
> >> 2.14.3
> >>
> >
> > By just looking at the code and commit message:
> >
> > Acked-by: Mathieu Malaterre 

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R Institute Poland
Samsung Electronics

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Re: [PATCH v2] Fixing arbitrary kernel leak in case FBIOGETCMAP_SPARC in sbusfb_ioctl_helper().

[Peter Malone]

Hi folks,

CVE-2018-6412 has been created for this. Is it possible for you to add a
note indicating the CVE number when merging the patch?

I received the CVE number after the patch was created and ack'd, which is
why I didn't include it in the commit message.



On Jan 31, 2018 10:49, "Mathieu Malaterre"  wrote:

> Hi Peter,
>
> On Wed, Jan 31, 2018 at 3:57 PM, Peter Malone 
> wrote:
> > Fixing arbitrary kernel leak in case FBIOGETCMAP_SPARC in
> > sbusfb_ioctl_helper().
> >
> > 'index' is defined as an int in sbusfb_ioctl_helper().
> > We retrieve this from the user:
> > if (get_user(index, >index) ||
> > __get_user(count, >count) ||
> > __get_user(ured, >red) ||
> > __get_user(ugreen, >green) ||
> > __get_user(ublue, >blue))
> >return -EFAULT;
> >
> > and then we use 'index' in the following way:
> > red = cmap->red[index + i] >> 8;
> > green = cmap->green[index + i] >> 8;
> > blue = cmap->blue[index + i] >> 8;
> >
> > This is a classic information leak vulnerability. 'index' should be
> > an unsigned int, given its usage above.
> >
> > This patch is straight-forward; it changes 'index' to unsigned int
> > in two switch-cases: FBIOGETCMAP_SPARC && FBIOPUTCMAP_SPARC.
> >
> > Signed-off-by: Peter Malone 
> > ---
>
> much better :)
>
> > v2: fixed formatting
> >
> >  drivers/video/fbdev/sbuslib.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/video/fbdev/sbuslib.c
> b/drivers/video/fbdev/sbuslib.c
> > index af6fc97f4ba4..a436d44f1b7f 100644
> > --- a/drivers/video/fbdev/sbuslib.c
> > +++ b/drivers/video/fbdev/sbuslib.c
> > @@ -122,7 +122,7 @@ int sbusfb_ioctl_helper(unsigned long cmd, unsigned
> long arg,
> > unsigned char __user *ured;
> > unsigned char __user *ugreen;
> > unsigned char __user *ublue;
> > -   int index, count, i;
> > +   unsigned int index, count, i;
> >
> > if (get_user(index, >index) ||
> > __get_user(count, >count) ||
> > @@ -161,7 +161,7 @@ int sbusfb_ioctl_helper(unsigned long cmd, unsigned
> long arg,
> > unsigned char __user *ugreen;
> > unsigned char __user *ublue;
> > struct fb_cmap *cmap = >cmap;
> > -   int index, count, i;
> > +   unsigned int index, count, i;
> > u8 red, green, blue;
> >
> > if (get_user(index, >index) ||
> > --
> > 2.14.3
> >
>
> By just looking at the code and commit message:
>
> Acked-by: Mathieu Malaterre 
>
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Re: [PATCH v2] Fixing arbitrary kernel leak in case FBIOGETCMAP_SPARC in sbusfb_ioctl_helper().

[Peter Malone]

Hi folks,

CVE-2018-6412 has been created for this. Is it possible for you to add
a note indicating the CVE number when merging the patch?

I received the CVE number after the patch was created and ack'd, which
is why I didn't include it in the commit message.

On Wed, Jan 31, 2018 at 10:49 AM, Mathieu Malaterre  wrote:
> Hi Peter,
>
> On Wed, Jan 31, 2018 at 3:57 PM, Peter Malone  wrote:
>> Fixing arbitrary kernel leak in case FBIOGETCMAP_SPARC in
>> sbusfb_ioctl_helper().
>>
>> 'index' is defined as an int in sbusfb_ioctl_helper().
>> We retrieve this from the user:
>> if (get_user(index, >index) ||
>> __get_user(count, >count) ||
>> __get_user(ured, >red) ||
>> __get_user(ugreen, >green) ||
>> __get_user(ublue, >blue))
>>return -EFAULT;
>>
>> and then we use 'index' in the following way:
>> red = cmap->red[index + i] >> 8;
>> green = cmap->green[index + i] >> 8;
>> blue = cmap->blue[index + i] >> 8;
>>
>> This is a classic information leak vulnerability. 'index' should be
>> an unsigned int, given its usage above.
>>
>> This patch is straight-forward; it changes 'index' to unsigned int
>> in two switch-cases: FBIOGETCMAP_SPARC && FBIOPUTCMAP_SPARC.
>>
>> Signed-off-by: Peter Malone 
>> ---
>
> much better :)
>
>> v2: fixed formatting
>>
>>  drivers/video/fbdev/sbuslib.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/video/fbdev/sbuslib.c b/drivers/video/fbdev/sbuslib.c
>> index af6fc97f4ba4..a436d44f1b7f 100644
>> --- a/drivers/video/fbdev/sbuslib.c
>> +++ b/drivers/video/fbdev/sbuslib.c
>> @@ -122,7 +122,7 @@ int sbusfb_ioctl_helper(unsigned long cmd, unsigned long 
>> arg,
>> unsigned char __user *ured;
>> unsigned char __user *ugreen;
>> unsigned char __user *ublue;
>> -   int index, count, i;
>> +   unsigned int index, count, i;
>>
>> if (get_user(index, >index) ||
>> __get_user(count, >count) ||
>> @@ -161,7 +161,7 @@ int sbusfb_ioctl_helper(unsigned long cmd, unsigned long 
>> arg,
>> unsigned char __user *ugreen;
>> unsigned char __user *ublue;
>> struct fb_cmap *cmap = >cmap;
>> -   int index, count, i;
>> +   unsigned int index, count, i;
>> u8 red, green, blue;
>>
>> if (get_user(index, >index) ||
>> --
>> 2.14.3
>>
>
> By just looking at the code and commit message:
>
> Acked-by: Mathieu Malaterre 



-- 
Regards,
Peter.
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Re: [PATCH v2] Fixing arbitrary kernel leak in case FBIOGETCMAP_SPARC in sbusfb_ioctl_helper().

[Mathieu Malaterre]

Hi Peter,

On Wed, Jan 31, 2018 at 3:57 PM, Peter Malone  wrote:
> Fixing arbitrary kernel leak in case FBIOGETCMAP_SPARC in
> sbusfb_ioctl_helper().
>
> 'index' is defined as an int in sbusfb_ioctl_helper().
> We retrieve this from the user:
> if (get_user(index, >index) ||
> __get_user(count, >count) ||
> __get_user(ured, >red) ||
> __get_user(ugreen, >green) ||
> __get_user(ublue, >blue))
>return -EFAULT;
>
> and then we use 'index' in the following way:
> red = cmap->red[index + i] >> 8;
> green = cmap->green[index + i] >> 8;
> blue = cmap->blue[index + i] >> 8;
>
> This is a classic information leak vulnerability. 'index' should be
> an unsigned int, given its usage above.
>
> This patch is straight-forward; it changes 'index' to unsigned int
> in two switch-cases: FBIOGETCMAP_SPARC && FBIOPUTCMAP_SPARC.
>
> Signed-off-by: Peter Malone 
> ---

much better :)

> v2: fixed formatting
>
>  drivers/video/fbdev/sbuslib.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/video/fbdev/sbuslib.c b/drivers/video/fbdev/sbuslib.c
> index af6fc97f4ba4..a436d44f1b7f 100644
> --- a/drivers/video/fbdev/sbuslib.c
> +++ b/drivers/video/fbdev/sbuslib.c
> @@ -122,7 +122,7 @@ int sbusfb_ioctl_helper(unsigned long cmd, unsigned long 
> arg,
> unsigned char __user *ured;
> unsigned char __user *ugreen;
> unsigned char __user *ublue;
> -   int index, count, i;
> +   unsigned int index, count, i;
>
> if (get_user(index, >index) ||
> __get_user(count, >count) ||
> @@ -161,7 +161,7 @@ int sbusfb_ioctl_helper(unsigned long cmd, unsigned long 
> arg,
> unsigned char __user *ugreen;
> unsigned char __user *ublue;
> struct fb_cmap *cmap = >cmap;
> -   int index, count, i;
> +   unsigned int index, count, i;
> u8 red, green, blue;
>
> if (get_user(index, >index) ||
> --
> 2.14.3
>

By just looking at the code and commit message:

Acked-by: Mathieu Malaterre 
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