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* [PATCH] fbdev/omapfb: fix omapfb_memory_read infoleak
@ 2018-09-12  7:30   ` Tomi Valkeinen
  0 siblings, 0 replies; 7+ messages in thread
From: Tomi Valkeinen @ 2018-09-12  7:30 UTC (permalink / raw)
  To: linux-fbdev, Bartlomiej Zolnierkiewicz
  Cc: Tomi Valkeinen, stable, security, Will Deacon, Jann Horn, Tony Lindgren

OMAPFB_MEMORY_READ ioctl reads pixels from the LCD's memory and copies
them to a userspace buffer. The code has two issues:

- The user provided width and height could be large enough to overflow
  the calculations
- The copy_to_user() can copy uninitialized memory to the userspace,
  which might contain sensitive kernel information.

Fix these by limiting the width & height parameters, and only copying
the amount of data that we actually received from the LCD.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reported-by: Jann Horn <jannh@google.com>
Cc: stable@vger.kernel.org
Cc: security@kernel.org
Cc: Will Deacon <will.deacon@arm.com>
Cc: Jann Horn <jannh@google.com>
Cc: Tony Lindgren <tony@atomide.com>
---
 drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c b/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c
index ef69273074ba..a3edb20ea4c3 100644
--- a/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c
+++ b/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c
@@ -496,6 +496,9 @@ static int omapfb_memory_read(struct fb_info *fbi,
 	if (!access_ok(VERIFY_WRITE, mr->buffer, mr->buffer_size))
 		return -EFAULT;
 
+	if (mr->w > 4096 || mr->h > 4096)
+		return -EINVAL;
+
 	if (mr->w * mr->h * 3 > mr->buffer_size)
 		return -EINVAL;
 
@@ -509,7 +512,7 @@ static int omapfb_memory_read(struct fb_info *fbi,
 			mr->x, mr->y, mr->w, mr->h);
 
 	if (r > 0) {
-		if (copy_to_user(mr->buffer, buf, mr->buffer_size))
+		if (copy_to_user(mr->buffer, buf, r))
 			r = -EFAULT;
 	}
 
-- 
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

^ permalink raw reply related	[flat|nested] 7+ messages in thread
* [PATCH] fbdev/omapfb: fix omapfb_memory_read infoleak
@ 2018-09-12  7:30   ` Tomi Valkeinen
  0 siblings, 0 replies; 7+ messages in thread
From: Tomi Valkeinen @ 2018-09-12  7:30 UTC (permalink / raw)
  To: linux-fbdev, Bartlomiej Zolnierkiewicz
  Cc: Tomi Valkeinen, stable, security, Will Deacon, Jann Horn, Tony Lindgren

OMAPFB_MEMORY_READ ioctl reads pixels from the LCD's memory and copies
them to a userspace buffer. The code has two issues:

- The user provided width and height could be large enough to overflow
  the calculations
- The copy_to_user() can copy uninitialized memory to the userspace,
  which might contain sensitive kernel information.

Fix these by limiting the width & height parameters, and only copying
the amount of data that we actually received from the LCD.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reported-by: Jann Horn <jannh@google.com>
Cc: stable@vger.kernel.org
Cc: security@kernel.org
Cc: Will Deacon <will.deacon@arm.com>
Cc: Jann Horn <jannh@google.com>
Cc: Tony Lindgren <tony@atomide.com>
---
 drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c b/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c
index ef69273074ba..a3edb20ea4c3 100644
--- a/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c
+++ b/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c
@@ -496,6 +496,9 @@ static int omapfb_memory_read(struct fb_info *fbi,
 	if (!access_ok(VERIFY_WRITE, mr->buffer, mr->buffer_size))
 		return -EFAULT;
 
+	if (mr->w > 4096 || mr->h > 4096)
+		return -EINVAL;
+
 	if (mr->w * mr->h * 3 > mr->buffer_size)
 		return -EINVAL;
 
@@ -509,7 +512,7 @@ static int omapfb_memory_read(struct fb_info *fbi,
 			mr->x, mr->y, mr->w, mr->h);
 
 	if (r > 0) {
-		if (copy_to_user(mr->buffer, buf, mr->buffer_size))
+		if (copy_to_user(mr->buffer, buf, r))
 			r = -EFAULT;
 	}
 
-- 
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

^ permalink raw reply related	[flat|nested] 7+ messages in thread
* Re: [PATCH] fbdev/omapfb: fix omapfb_memory_read infoleak
  2018-09-12  7:30   ` Tomi Valkeinen
@ 2018-09-12 17:32     ` Kees Cook
  -1 siblings, 0 replies; 7+ messages in thread
From: Kees Cook @ 2018-09-12 17:32 UTC (permalink / raw)
  To: Tomi Valkeinen
  Cc: linux-fbdev, Bartlomiej Zolnierkiewicz, # 3.4.x,
	Security Officers, Will Deacon, Jann Horn, Tony Lindgren

On Wed, Sep 12, 2018 at 12:30 AM, Tomi Valkeinen <tomi.valkeinen@ti.com> wrote:
> OMAPFB_MEMORY_READ ioctl reads pixels from the LCD's memory and copies
> them to a userspace buffer. The code has two issues:
>
> - The user provided width and height could be large enough to overflow
>   the calculations
> - The copy_to_user() can copy uninitialized memory to the userspace,
>   which might contain sensitive kernel information.
>
> Fix these by limiting the width & height parameters, and only copying
> the amount of data that we actually received from the LCD.
>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> Reported-by: Jann Horn <jannh@google.com>
> Cc: stable@vger.kernel.org
> Cc: security@kernel.org
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Jann Horn <jannh@google.com>
> Cc: Tony Lindgren <tony@atomide.com>
> ---
>  drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c b/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c
> index ef69273074ba..a3edb20ea4c3 100644
> --- a/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c
> +++ b/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c
> @@ -496,6 +496,9 @@ static int omapfb_memory_read(struct fb_info *fbi,
>         if (!access_ok(VERIFY_WRITE, mr->buffer, mr->buffer_size))
>                 return -EFAULT;
>
> +       if (mr->w > 4096 || mr->h > 4096)
> +               return -EINVAL;
> +
>         if (mr->w * mr->h * 3 > mr->buffer_size)
>                 return -EINVAL;

alternatively, replace the above two tests with:

alloc_size = array3_size(mr->w, mr->h, 3);
if (alloc_size > mr->buffer_size)
    return -EINVAL;

buf = vmalloc(alloc_size);
...

>
> @@ -509,7 +512,7 @@ static int omapfb_memory_read(struct fb_info *fbi,
>                         mr->x, mr->y, mr->w, mr->h);
>
>         if (r > 0) {
> -               if (copy_to_user(mr->buffer, buf, mr->buffer_size))
> +               if (copy_to_user(mr->buffer, buf, r))

But yes, this seems correct regardless: userspace was being
overwritten beyond "r", potentially.

-Kees

>                         r = -EFAULT;
>         }
>
> --
> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
> Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
>



-- 
Kees Cook
Pixel Security

^ permalink raw reply	[flat|nested] 7+ messages in thread
* Re: [PATCH] fbdev/omapfb: fix omapfb_memory_read infoleak
@ 2018-09-12 17:32     ` Kees Cook
  0 siblings, 0 replies; 7+ messages in thread
From: Kees Cook @ 2018-09-12 17:32 UTC (permalink / raw)
  To: Tomi Valkeinen
  Cc: linux-fbdev, Bartlomiej Zolnierkiewicz, # 3.4.x,
	Security Officers, Will Deacon, Jann Horn, Tony Lindgren

On Wed, Sep 12, 2018 at 12:30 AM, Tomi Valkeinen <tomi.valkeinen@ti.com> wrote:
> OMAPFB_MEMORY_READ ioctl reads pixels from the LCD's memory and copies
> them to a userspace buffer. The code has two issues:
>
> - The user provided width and height could be large enough to overflow
>   the calculations
> - The copy_to_user() can copy uninitialized memory to the userspace,
>   which might contain sensitive kernel information.
>
> Fix these by limiting the width & height parameters, and only copying
> the amount of data that we actually received from the LCD.
>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> Reported-by: Jann Horn <jannh@google.com>
> Cc: stable@vger.kernel.org
> Cc: security@kernel.org
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Jann Horn <jannh@google.com>
> Cc: Tony Lindgren <tony@atomide.com>
> ---
>  drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c b/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c
> index ef69273074ba..a3edb20ea4c3 100644
> --- a/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c
> +++ b/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c
> @@ -496,6 +496,9 @@ static int omapfb_memory_read(struct fb_info *fbi,
>         if (!access_ok(VERIFY_WRITE, mr->buffer, mr->buffer_size))
>                 return -EFAULT;
>
> +       if (mr->w > 4096 || mr->h > 4096)
> +               return -EINVAL;
> +
>         if (mr->w * mr->h * 3 > mr->buffer_size)
>                 return -EINVAL;

alternatively, replace the above two tests with:

alloc_size = array3_size(mr->w, mr->h, 3);
if (alloc_size > mr->buffer_size)
    return -EINVAL;

buf = vmalloc(alloc_size);
...

>
> @@ -509,7 +512,7 @@ static int omapfb_memory_read(struct fb_info *fbi,
>                         mr->x, mr->y, mr->w, mr->h);
>
>         if (r > 0) {
> -               if (copy_to_user(mr->buffer, buf, mr->buffer_size))
> +               if (copy_to_user(mr->buffer, buf, r))

But yes, this seems correct regardless: userspace was being
overwritten beyond "r", potentially.

-Kees

>                         r = -EFAULT;
>         }
>
> --
> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
> Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
>



-- 
Kees Cook
Pixel Security

^ permalink raw reply	[flat|nested] 7+ messages in thread
* Re: [PATCH] fbdev/omapfb: fix omapfb_memory_read infoleak
  2018-09-12  7:30   ` Tomi Valkeinen
  (?)
@ 2018-09-26 15:45     ` Bartlomiej Zolnierkiewicz
  -1 siblings, 0 replies; 7+ messages in thread
From: Bartlomiej Zolnierkiewicz @ 2018-09-26 15:45 UTC (permalink / raw)
  To: Tomi Valkeinen
  Cc: linux-fbdev, dri-devel, stable, security, Will Deacon, Jann Horn,
	Tony Lindgren


[ added dri-devel@lists.freedesktop.org to Cc: ]

On 09/12/2018 09:30 AM, Tomi Valkeinen wrote:
> OMAPFB_MEMORY_READ ioctl reads pixels from the LCD's memory and copies
> them to a userspace buffer. The code has two issues:
> 
> - The user provided width and height could be large enough to overflow
>   the calculations
> - The copy_to_user() can copy uninitialized memory to the userspace,
>   which might contain sensitive kernel information.
> 
> Fix these by limiting the width & height parameters, and only copying
> the amount of data that we actually received from the LCD.
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> Reported-by: Jann Horn <jannh@google.com>
> Cc: stable@vger.kernel.org
> Cc: security@kernel.org
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Jann Horn <jannh@google.com>
> Cc: Tony Lindgren <tony@atomide.com>

Patch queued for 4.19, thanks.

> ---
>  drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c b/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c
> index ef69273074ba..a3edb20ea4c3 100644
> --- a/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c
> +++ b/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c
> @@ -496,6 +496,9 @@ static int omapfb_memory_read(struct fb_info *fbi,
>  	if (!access_ok(VERIFY_WRITE, mr->buffer, mr->buffer_size))
>  		return -EFAULT;
>  
> +	if (mr->w > 4096 || mr->h > 4096)
> +		return -EINVAL;
> +
>  	if (mr->w * mr->h * 3 > mr->buffer_size)
>  		return -EINVAL;
>  
> @@ -509,7 +512,7 @@ static int omapfb_memory_read(struct fb_info *fbi,
>  			mr->x, mr->y, mr->w, mr->h);
>  
>  	if (r > 0) {
> -		if (copy_to_user(mr->buffer, buf, mr->buffer_size))
> +		if (copy_to_user(mr->buffer, buf, r))
>  			r = -EFAULT;
>  	}

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

^ permalink raw reply	[flat|nested] 7+ messages in thread
* Re: [PATCH] fbdev/omapfb: fix omapfb_memory_read infoleak
@ 2018-09-26 15:45     ` Bartlomiej Zolnierkiewicz
  0 siblings, 0 replies; 7+ messages in thread
From: Bartlomiej Zolnierkiewicz @ 2018-09-26 15:45 UTC (permalink / raw)
  To: Tomi Valkeinen
  Cc: linux-fbdev, dri-devel, stable, security, Will Deacon, Jann Horn,
	Tony Lindgren


[ added dri-devel@lists.freedesktop.org to Cc: ]

On 09/12/2018 09:30 AM, Tomi Valkeinen wrote:
> OMAPFB_MEMORY_READ ioctl reads pixels from the LCD's memory and copies
> them to a userspace buffer. The code has two issues:
> 
> - The user provided width and height could be large enough to overflow
>   the calculations
> - The copy_to_user() can copy uninitialized memory to the userspace,
>   which might contain sensitive kernel information.
> 
> Fix these by limiting the width & height parameters, and only copying
> the amount of data that we actually received from the LCD.
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> Reported-by: Jann Horn <jannh@google.com>
> Cc: stable@vger.kernel.org
> Cc: security@kernel.org
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Jann Horn <jannh@google.com>
> Cc: Tony Lindgren <tony@atomide.com>

Patch queued for 4.19, thanks.

> ---
>  drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c b/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c
> index ef69273074ba..a3edb20ea4c3 100644
> --- a/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c
> +++ b/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c
> @@ -496,6 +496,9 @@ static int omapfb_memory_read(struct fb_info *fbi,
>  	if (!access_ok(VERIFY_WRITE, mr->buffer, mr->buffer_size))
>  		return -EFAULT;
>  
> +	if (mr->w > 4096 || mr->h > 4096)
> +		return -EINVAL;
> +
>  	if (mr->w * mr->h * 3 > mr->buffer_size)
>  		return -EINVAL;
>  
> @@ -509,7 +512,7 @@ static int omapfb_memory_read(struct fb_info *fbi,
>  			mr->x, mr->y, mr->w, mr->h);
>  
>  	if (r > 0) {
> -		if (copy_to_user(mr->buffer, buf, mr->buffer_size))
> +		if (copy_to_user(mr->buffer, buf, r))
>  			r = -EFAULT;
>  	}

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

^ permalink raw reply	[flat|nested] 7+ messages in thread
* Re: [PATCH] fbdev/omapfb: fix omapfb_memory_read infoleak
@ 2018-09-26 15:45     ` Bartlomiej Zolnierkiewicz
  0 siblings, 0 replies; 7+ messages in thread
From: Bartlomiej Zolnierkiewicz @ 2018-09-26 15:45 UTC (permalink / raw)
  To: Tomi Valkeinen
  Cc: linux-fbdev, dri-devel, stable, security, Will Deacon, Jann Horn,
	Tony Lindgren


[ added dri-devel@lists.freedesktop.org to Cc: ]

On 09/12/2018 09:30 AM, Tomi Valkeinen wrote:
> OMAPFB_MEMORY_READ ioctl reads pixels from the LCD's memory and copies
> them to a userspace buffer. The code has two issues:
> 
> - The user provided width and height could be large enough to overflow
>   the calculations
> - The copy_to_user() can copy uninitialized memory to the userspace,
>   which might contain sensitive kernel information.
> 
> Fix these by limiting the width & height parameters, and only copying
> the amount of data that we actually received from the LCD.
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> Reported-by: Jann Horn <jannh@google.com>
> Cc: stable@vger.kernel.org
> Cc: security@kernel.org
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Jann Horn <jannh@google.com>
> Cc: Tony Lindgren <tony@atomide.com>

Patch queued for 4.19, thanks.

> ---
>  drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c b/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c
> index ef69273074ba..a3edb20ea4c3 100644
> --- a/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c
> +++ b/drivers/video/fbdev/omap2/omapfb/omapfb-ioctl.c
> @@ -496,6 +496,9 @@ static int omapfb_memory_read(struct fb_info *fbi,
>  	if (!access_ok(VERIFY_WRITE, mr->buffer, mr->buffer_size))
>  		return -EFAULT;
>  
> +	if (mr->w > 4096 || mr->h > 4096)
> +		return -EINVAL;
> +
>  	if (mr->w * mr->h * 3 > mr->buffer_size)
>  		return -EINVAL;
>  
> @@ -509,7 +512,7 @@ static int omapfb_memory_read(struct fb_info *fbi,
>  			mr->x, mr->y, mr->w, mr->h);
>  
>  	if (r > 0) {
> -		if (copy_to_user(mr->buffer, buf, mr->buffer_size))
> +		if (copy_to_user(mr->buffer, buf, r))
>  			r = -EFAULT;
>  	}

Best regards,

^ permalink raw reply	[flat|nested] 7+ messages in thread
end of thread, other threads:[~2018-09-26 21:59 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
     [not found] <CGME20180912073137epcas5p36de373cd9715ad2a2b60c5206c08e5cf@epcas5p3.samsung.com>
2018-09-12  7:30 ` [PATCH] fbdev/omapfb: fix omapfb_memory_read infoleak Tomi Valkeinen
2018-09-12  7:30   ` Tomi Valkeinen
2018-09-12 17:32   ` Kees Cook
2018-09-12 17:32     ` Kees Cook
2018-09-26 15:45   ` Bartlomiej Zolnierkiewicz
2018-09-26 15:45     ` Bartlomiej Zolnierkiewicz
2018-09-26 15:45     ` Bartlomiej Zolnierkiewicz

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