From: Oleksandr Andrushchenko <[email protected]>
It is possible that drm_simple_kms_plane_atomic_check called
with no CRTC set, e.g. when user-space application sets CRTC_ID/FB_ID
to 0 before doing any actual drawing. This leads to NULL pointer
dereference because in this case new CRTC state is NULL and must be
checked before accessing.
Signed-off-by: Oleksandr Andrushchenko <[email protected]>
Reviewed-by: Daniel Vetter <[email protected]>
---
Changes since initial:
- re-worked checks for null CRTC as suggested by Daniel Vetter
---
drivers/gpu/drm/drm_simple_kms_helper.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/drm_simple_kms_helper.c b/drivers/gpu/drm/drm_simple_kms_helper.c
index 9ca8a4a59b74..4a1dbd88b1ec 100644
--- a/drivers/gpu/drm/drm_simple_kms_helper.c
+++ b/drivers/gpu/drm/drm_simple_kms_helper.c
@@ -121,12 +121,6 @@ static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
pipe = container_of(plane, struct drm_simple_display_pipe, plane);
crtc_state = drm_atomic_get_new_crtc_state(plane_state->state,
&pipe->crtc);
- if (!crtc_state->enable)
- return 0; /* nothing to check when disabling or disabled */
-
- if (crtc_state->enable)
- drm_mode_get_hv_timing(&crtc_state->mode,
- &clip.x2, &clip.y2);
ret = drm_atomic_helper_check_plane_state(plane_state, crtc_state,
&clip,
@@ -137,7 +131,9 @@ static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
return ret;
if (!plane_state->visible)
- return -EINVAL;
+ return 0;
+
+ drm_mode_get_hv_timing(&crtc_state->mode, &clip.x2, &clip.y2);
if (!pipe->funcs || !pipe->funcs->check)
return 0;
--
2.7.4
On 02/22/2018 08:09 AM, Oleksandr Andrushchenko wrote:
> From: Oleksandr Andrushchenko <[email protected]>
>
> It is possible that drm_simple_kms_plane_atomic_check called
> with no CRTC set, e.g. when user-space application sets CRTC_ID/FB_ID
> to 0 before doing any actual drawing. This leads to NULL pointer
> dereference because in this case new CRTC state is NULL and must be
> checked before accessing.
>
> Signed-off-by: Oleksandr Andrushchenko <[email protected]>
> Reviewed-by: Daniel Vetter <[email protected]>
>
> ---
> Changes since initial:
> - re-worked checks for null CRTC as suggested by Daniel Vetter
> ---
> drivers/gpu/drm/drm_simple_kms_helper.c | 10 +++-------
> 1 file changed, 3 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_simple_kms_helper.c b/drivers/gpu/drm/drm_simple_kms_helper.c
> index 9ca8a4a59b74..4a1dbd88b1ec 100644
> --- a/drivers/gpu/drm/drm_simple_kms_helper.c
> +++ b/drivers/gpu/drm/drm_simple_kms_helper.c
> @@ -121,12 +121,6 @@ static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
> pipe = container_of(plane, struct drm_simple_display_pipe, plane);
> crtc_state = drm_atomic_get_new_crtc_state(plane_state->state,
> &pipe->crtc);
> - if (!crtc_state->enable)
> - return 0; /* nothing to check when disabling or disabled */
> -
> - if (crtc_state->enable)
> - drm_mode_get_hv_timing(&crtc_state->mode,
> - &clip.x2, &clip.y2);
>
> ret = drm_atomic_helper_check_plane_state(plane_state, crtc_state,
> &clip,
> @@ -137,7 +131,9 @@ static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
> return ret;
>
> if (!plane_state->visible)
> - return -EINVAL;
Daniel, I have put your R-b tag, but I had removed suggested
"WARN_ON(crtc_state && crtc_state->enable);"
here as it fires each time when crtc_state is not NULL.
Please let me know if this is not ok and you want me to remove
your R-b tag.
> + return 0;
> +
> + drm_mode_get_hv_timing(&crtc_state->mode, &clip.x2, &clip.y2);
>
> if (!pipe->funcs || !pipe->funcs->check)
> return 0;
Thank you,
Oleksandr
On Thu, Feb 22, 2018 at 08:12:48AM +0200, Oleksandr Andrushchenko wrote:
> On 02/22/2018 08:09 AM, Oleksandr Andrushchenko wrote:
> > From: Oleksandr Andrushchenko <[email protected]>
> >
> > It is possible that drm_simple_kms_plane_atomic_check called
> > with no CRTC set, e.g. when user-space application sets CRTC_ID/FB_ID
> > to 0 before doing any actual drawing. This leads to NULL pointer
> > dereference because in this case new CRTC state is NULL and must be
> > checked before accessing.
> >
> > Signed-off-by: Oleksandr Andrushchenko <[email protected]>
> > Reviewed-by: Daniel Vetter <[email protected]>
> >
> > ---
> > Changes since initial:
> > - re-worked checks for null CRTC as suggested by Daniel Vetter
> > ---
> > drivers/gpu/drm/drm_simple_kms_helper.c | 10 +++-------
> > 1 file changed, 3 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/drm_simple_kms_helper.c b/drivers/gpu/drm/drm_simple_kms_helper.c
> > index 9ca8a4a59b74..4a1dbd88b1ec 100644
> > --- a/drivers/gpu/drm/drm_simple_kms_helper.c
> > +++ b/drivers/gpu/drm/drm_simple_kms_helper.c
> > @@ -121,12 +121,6 @@ static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
> > pipe = container_of(plane, struct drm_simple_display_pipe, plane);
> > crtc_state = drm_atomic_get_new_crtc_state(plane_state->state,
> > &pipe->crtc);
> > - if (!crtc_state->enable)
> > - return 0; /* nothing to check when disabling or disabled */
> > -
> > - if (crtc_state->enable)
> > - drm_mode_get_hv_timing(&crtc_state->mode,
> > - &clip.x2, &clip.y2);
> > ret = drm_atomic_helper_check_plane_state(plane_state, crtc_state,
> > &clip,
> > @@ -137,7 +131,9 @@ static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
> > return ret;
> > if (!plane_state->visible)
> > - return -EINVAL;
> Daniel, I have put your R-b tag, but I had removed suggested
> "WARN_ON(crtc_state && crtc_state->enable);"
> here as it fires each time when crtc_state is not NULL.
> Please let me know if this is not ok and you want me to remove
> your R-b tag.
I'm a bit confused why that fires, but oh well. Applied, thanks for your
patch.
-Daniel
> > + return 0;
> > +
> > + drm_mode_get_hv_timing(&crtc_state->mode, &clip.x2, &clip.y2);
> > if (!pipe->funcs || !pipe->funcs->check)
> > return 0;
> Thank you,
> Oleksandr
> _______________________________________________
> dri-devel mailing list
> [email protected]
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
On 02/22/2018 06:11 PM, Daniel Vetter wrote:
> On Thu, Feb 22, 2018 at 08:12:48AM +0200, Oleksandr Andrushchenko wrote:
>> On 02/22/2018 08:09 AM, Oleksandr Andrushchenko wrote:
>>> From: Oleksandr Andrushchenko <[email protected]>
>>>
>>> It is possible that drm_simple_kms_plane_atomic_check called
>>> with no CRTC set, e.g. when user-space application sets CRTC_ID/FB_ID
>>> to 0 before doing any actual drawing. This leads to NULL pointer
>>> dereference because in this case new CRTC state is NULL and must be
>>> checked before accessing.
>>>
>>> Signed-off-by: Oleksandr Andrushchenko <[email protected]>
>>> Reviewed-by: Daniel Vetter <[email protected]>
>>>
>>> ---
>>> Changes since initial:
>>> - re-worked checks for null CRTC as suggested by Daniel Vetter
>>> ---
>>> drivers/gpu/drm/drm_simple_kms_helper.c | 10 +++-------
>>> 1 file changed, 3 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/drm_simple_kms_helper.c b/drivers/gpu/drm/drm_simple_kms_helper.c
>>> index 9ca8a4a59b74..4a1dbd88b1ec 100644
>>> --- a/drivers/gpu/drm/drm_simple_kms_helper.c
>>> +++ b/drivers/gpu/drm/drm_simple_kms_helper.c
>>> @@ -121,12 +121,6 @@ static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
>>> pipe = container_of(plane, struct drm_simple_display_pipe, plane);
>>> crtc_state = drm_atomic_get_new_crtc_state(plane_state->state,
>>> &pipe->crtc);
>>> - if (!crtc_state->enable)
>>> - return 0; /* nothing to check when disabling or disabled */
>>> -
>>> - if (crtc_state->enable)
>>> - drm_mode_get_hv_timing(&crtc_state->mode,
>>> - &clip.x2, &clip.y2);
>>> ret = drm_atomic_helper_check_plane_state(plane_state, crtc_state,
>>> &clip,
>>> @@ -137,7 +131,9 @@ static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
>>> return ret;
>>> if (!plane_state->visible)
>>> - return -EINVAL;
>> Daniel, I have put your R-b tag, but I had removed suggested
>> "WARN_ON(crtc_state && crtc_state->enable);"
>> here as it fires each time when crtc_state is not NULL.
>> Please let me know if this is not ok and you want me to remove
>> your R-b tag.
> I'm a bit confused why that fires, but oh well. Applied, thanks for your
> patch.
Thank you
> -Daniel
>
>>> + return 0;
>>> +
>>> + drm_mode_get_hv_timing(&crtc_state->mode, &clip.x2, &clip.y2);
>>> if (!pipe->funcs || !pipe->funcs->check)
>>> return 0;
>> Thank you,
>> Oleksandr
>> _______________________________________________
>> dri-devel mailing list
>> [email protected]
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel