Re: [PATCH] kernel: drm/vmwgfx: limit the number of mip levels in vmw_gb_surface_define_ioctl()

[Vladis Dronov]

Hello, Sinclair!

> Here, the check should be "> DRM_VMW_MAX_MIP_LEVELS" because req->mip_levels
> is only for one layer.

Got it, thanks!

> Also, as long as we can doing a check, I would suggest we check for 0 as
> well.

Do you mean a check for "req->mip_levels > 0" or for "req->mip_levels >= 0" ?

I glimpsed thru the code and I do not see problems with req->mip_levels being 0,
surely I may be mistaking.

Best regards,
Vladis Dronov | Red Hat, Inc. | Product Security Engineer


- Original Message -
From: "Sinclair Yeh" 
To: "Vladis Dronov" 
Cc: "VMware Graphics" , "Thomas 
Hellstrom" , "David Airlie" , 
dri-de...@lists.freedesktop.org, linux-kernel@vger.kernel.org
Sent: Friday, March 31, 2017 5:07:12 PM
Subject: Re: [PATCH] kernel: drm/vmwgfx: limit the number of mip levels in 
vmw_gb_surface_define_ioctl()

Hi Vladis,


On Thu, Mar 30, 2017 at 12:27:12PM +0200, Vladis Dronov wrote:
> The 'req->mip_levels' parameter in vmw_gb_surface_define_ioctl() is
> a user-controlled 'uint32_t' value which is used as a loop count limit.
> This can lead to a kernel lockup and DoS. Add check for 'req->mip_levels'.
> 
> References:
> https://urldefense.proofpoint.com/v2/url?u=https-3A__bugzilla.redhat.com_show-5Fbug.cgi-3Fid-3D1437431=DwIBAg=uilaK90D4TOVoH58JNXRgQ=HaJ2a6NYExoV0cntAYcoqA=5yR87BuuU86aoAjCveInxh6jvgOyumqIHQhTs0xLo38=tWQs7vwNLgD_b2RWMddVtusEKh9FQTIF5rKFOWudslE=
>  
> Signed-off-by: Vladis Dronov 
> ---
>  drivers/gpu/drm/vmwgfx/vmwgfx_surface.c | 4 
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c 
> b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
> index b445ce9..b30824b 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
> @@ -1281,6 +1281,10 @@ int vmw_gb_surface_define_ioctl(struct drm_device 
> *dev, void *data,
>   if (req->multisample_count != 0)
>   return -EINVAL;
>  
> + if (req->mip_levels > DRM_VMW_MAX_SURFACE_FACES *
> + DRM_VMW_MAX_MIP_LEVELS)
> + return -EINVAL;
> +

Here, the check should be "> DRM_VMW_MAX_MIP_LEVELS" because req->mip_levels
is only for one layer.

Also, as long as we can doing a check, I would suggest we check for 0 as
well.

Sinclair

Re: [PATCH] kernel: drm/vmwgfx: limit the number of mip levels in vmw_gb_surface_define_ioctl()

[Vladis Dronov]

Hello, Sinclair!

> Here, the check should be "> DRM_VMW_MAX_MIP_LEVELS" because req->mip_levels
> is only for one layer.

Got it, thanks!

> Also, as long as we can doing a check, I would suggest we check for 0 as
> well.

Do you mean a check for "req->mip_levels > 0" or for "req->mip_levels >= 0" ?

I glimpsed thru the code and I do not see problems with req->mip_levels being 0,
surely I may be mistaking.

Best regards,
Vladis Dronov | Red Hat, Inc. | Product Security Engineer


- Original Message -
From: "Sinclair Yeh" 
To: "Vladis Dronov" 
Cc: "VMware Graphics" , "Thomas 
Hellstrom" , "David Airlie" , 
dri-de...@lists.freedesktop.org, linux-kernel@vger.kernel.org
Sent: Friday, March 31, 2017 5:07:12 PM
Subject: Re: [PATCH] kernel: drm/vmwgfx: limit the number of mip levels in 
vmw_gb_surface_define_ioctl()

Hi Vladis,


On Thu, Mar 30, 2017 at 12:27:12PM +0200, Vladis Dronov wrote:
> The 'req->mip_levels' parameter in vmw_gb_surface_define_ioctl() is
> a user-controlled 'uint32_t' value which is used as a loop count limit.
> This can lead to a kernel lockup and DoS. Add check for 'req->mip_levels'.
> 
> References:
> https://urldefense.proofpoint.com/v2/url?u=https-3A__bugzilla.redhat.com_show-5Fbug.cgi-3Fid-3D1437431=DwIBAg=uilaK90D4TOVoH58JNXRgQ=HaJ2a6NYExoV0cntAYcoqA=5yR87BuuU86aoAjCveInxh6jvgOyumqIHQhTs0xLo38=tWQs7vwNLgD_b2RWMddVtusEKh9FQTIF5rKFOWudslE=
>  
> Signed-off-by: Vladis Dronov 
> ---
>  drivers/gpu/drm/vmwgfx/vmwgfx_surface.c | 4 
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c 
> b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
> index b445ce9..b30824b 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
> @@ -1281,6 +1281,10 @@ int vmw_gb_surface_define_ioctl(struct drm_device 
> *dev, void *data,
>   if (req->multisample_count != 0)
>   return -EINVAL;
>  
> + if (req->mip_levels > DRM_VMW_MAX_SURFACE_FACES *
> + DRM_VMW_MAX_MIP_LEVELS)
> + return -EINVAL;
> +

Here, the check should be "> DRM_VMW_MAX_MIP_LEVELS" because req->mip_levels
is only for one layer.

Also, as long as we can doing a check, I would suggest we check for 0 as
well.

Sinclair

Re: [PATCH] kernel: drm/vmwgfx: limit the number of mip levels in vmw_gb_surface_define_ioctl()

[Sinclair Yeh]

Hi Vladis,


On Thu, Mar 30, 2017 at 12:27:12PM +0200, Vladis Dronov wrote:
> The 'req->mip_levels' parameter in vmw_gb_surface_define_ioctl() is
> a user-controlled 'uint32_t' value which is used as a loop count limit.
> This can lead to a kernel lockup and DoS. Add check for 'req->mip_levels'.
> 
> References:
> https://urldefense.proofpoint.com/v2/url?u=https-3A__bugzilla.redhat.com_show-5Fbug.cgi-3Fid-3D1437431=DwIBAg=uilaK90D4TOVoH58JNXRgQ=HaJ2a6NYExoV0cntAYcoqA=5yR87BuuU86aoAjCveInxh6jvgOyumqIHQhTs0xLo38=tWQs7vwNLgD_b2RWMddVtusEKh9FQTIF5rKFOWudslE=
>  
> Signed-off-by: Vladis Dronov 
> ---
>  drivers/gpu/drm/vmwgfx/vmwgfx_surface.c | 4 
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c 
> b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
> index b445ce9..b30824b 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
> @@ -1281,6 +1281,10 @@ int vmw_gb_surface_define_ioctl(struct drm_device 
> *dev, void *data,
>   if (req->multisample_count != 0)
>   return -EINVAL;
>  
> + if (req->mip_levels > DRM_VMW_MAX_SURFACE_FACES *
> + DRM_VMW_MAX_MIP_LEVELS)
> + return -EINVAL;
> +

Here, the check should be "> DRM_VMW_MAX_MIP_LEVELS" because req->mip_levels
is only for one layer.

Also, as long as we can doing a check, I would suggest we check for 0 as
well.

Sinclair

Re: [PATCH] kernel: drm/vmwgfx: limit the number of mip levels in vmw_gb_surface_define_ioctl()

[Sinclair Yeh]

Hi Vladis,


On Thu, Mar 30, 2017 at 12:27:12PM +0200, Vladis Dronov wrote:
> The 'req->mip_levels' parameter in vmw_gb_surface_define_ioctl() is
> a user-controlled 'uint32_t' value which is used as a loop count limit.
> This can lead to a kernel lockup and DoS. Add check for 'req->mip_levels'.
> 
> References:
> https://urldefense.proofpoint.com/v2/url?u=https-3A__bugzilla.redhat.com_show-5Fbug.cgi-3Fid-3D1437431=DwIBAg=uilaK90D4TOVoH58JNXRgQ=HaJ2a6NYExoV0cntAYcoqA=5yR87BuuU86aoAjCveInxh6jvgOyumqIHQhTs0xLo38=tWQs7vwNLgD_b2RWMddVtusEKh9FQTIF5rKFOWudslE=
>  
> Signed-off-by: Vladis Dronov 
> ---
>  drivers/gpu/drm/vmwgfx/vmwgfx_surface.c | 4 
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c 
> b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
> index b445ce9..b30824b 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
> @@ -1281,6 +1281,10 @@ int vmw_gb_surface_define_ioctl(struct drm_device 
> *dev, void *data,
>   if (req->multisample_count != 0)
>   return -EINVAL;
>  
> + if (req->mip_levels > DRM_VMW_MAX_SURFACE_FACES *
> + DRM_VMW_MAX_MIP_LEVELS)
> + return -EINVAL;
> +

Here, the check should be "> DRM_VMW_MAX_MIP_LEVELS" because req->mip_levels
is only for one layer.

Also, as long as we can doing a check, I would suggest we check for 0 as
well.

Sinclair

Re: [PATCH] kernel: drm/vmwgfx: limit the number of mip levels in vmw_gb_surface_define_ioctl()

[Vladis Dronov]

This flaw was assigned an id CVE-2017-7346 by MITRE:

http://seclists.org/oss-sec/2017/q1/696

Best regards,
Vladis Dronov | Red Hat, Inc. | Product Security Engineer

- Original Message -
From: "Vladis Dronov" 
To: "VMware Graphics" , "Sinclair Yeh" 
, "Thomas Hellstrom" , "David Airlie" 
, dri-de...@lists.freedesktop.org, 
linux-kernel@vger.kernel.org
Cc: "Vladis Dronov" 
Sent: Thursday, March 30, 2017 12:27:12 PM
Subject: [PATCH] kernel: drm/vmwgfx: limit the number of mip levels in 
vmw_gb_surface_define_ioctl()

The 'req->mip_levels' parameter in vmw_gb_surface_define_ioctl() is
a user-controlled 'uint32_t' value which is used as a loop count limit.
This can lead to a kernel lockup and DoS. Add check for 'req->mip_levels'.

References:
https://bugzilla.redhat.com/show_bug.cgi?id=1437431
Signed-off-by: Vladis Dronov 

Re: [PATCH] kernel: drm/vmwgfx: limit the number of mip levels in vmw_gb_surface_define_ioctl()

[Vladis Dronov]

This flaw was assigned an id CVE-2017-7346 by MITRE:

http://seclists.org/oss-sec/2017/q1/696

Best regards,
Vladis Dronov | Red Hat, Inc. | Product Security Engineer

- Original Message -
From: "Vladis Dronov" 
To: "VMware Graphics" , "Sinclair Yeh" 
, "Thomas Hellstrom" , "David Airlie" 
, dri-de...@lists.freedesktop.org, 
linux-kernel@vger.kernel.org
Cc: "Vladis Dronov" 
Sent: Thursday, March 30, 2017 12:27:12 PM
Subject: [PATCH] kernel: drm/vmwgfx: limit the number of mip levels in 
vmw_gb_surface_define_ioctl()

The 'req->mip_levels' parameter in vmw_gb_surface_define_ioctl() is
a user-controlled 'uint32_t' value which is used as a loop count limit.
This can lead to a kernel lockup and DoS. Add check for 'req->mip_levels'.

References:
https://bugzilla.redhat.com/show_bug.cgi?id=1437431
Signed-off-by: Vladis Dronov 

[PATCH] kernel: drm/vmwgfx: limit the number of mip levels in vmw_gb_surface_define_ioctl()

[Vladis Dronov]

The 'req->mip_levels' parameter in vmw_gb_surface_define_ioctl() is
a user-controlled 'uint32_t' value which is used as a loop count limit.
This can lead to a kernel lockup and DoS. Add check for 'req->mip_levels'.

References:
https://bugzilla.redhat.com/show_bug.cgi?id=1437431
Signed-off-by: Vladis Dronov 
---
 drivers/gpu/drm/vmwgfx/vmwgfx_surface.c | 4 
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c 
b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
index b445ce9..b30824b 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
@@ -1281,6 +1281,10 @@ int vmw_gb_surface_define_ioctl(struct drm_device *dev, 
void *data,
if (req->multisample_count != 0)
return -EINVAL;
 
+   if (req->mip_levels > DRM_VMW_MAX_SURFACE_FACES *
+   DRM_VMW_MAX_MIP_LEVELS)
+   return -EINVAL;
+
if (unlikely(vmw_user_surface_size == 0))
vmw_user_surface_size = ttm_round_pot(sizeof(*user_srf)) +
128;
-- 
2.9.3

[PATCH] kernel: drm/vmwgfx: limit the number of mip levels in vmw_gb_surface_define_ioctl()

[Vladis Dronov]

The 'req->mip_levels' parameter in vmw_gb_surface_define_ioctl() is
a user-controlled 'uint32_t' value which is used as a loop count limit.
This can lead to a kernel lockup and DoS. Add check for 'req->mip_levels'.

References:
https://bugzilla.redhat.com/show_bug.cgi?id=1437431
Signed-off-by: Vladis Dronov 
---
 drivers/gpu/drm/vmwgfx/vmwgfx_surface.c | 4 
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c 
b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
index b445ce9..b30824b 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
@@ -1281,6 +1281,10 @@ int vmw_gb_surface_define_ioctl(struct drm_device *dev, 
void *data,
if (req->multisample_count != 0)
return -EINVAL;
 
+   if (req->mip_levels > DRM_VMW_MAX_SURFACE_FACES *
+   DRM_VMW_MAX_MIP_LEVELS)
+   return -EINVAL;
+
if (unlikely(vmw_user_surface_size == 0))
vmw_user_surface_size = ttm_round_pot(sizeof(*user_srf)) +
128;
-- 
2.9.3