lkml.org 
[lkml]   [2019]   [Mar]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] drm/atomic-helper: Validate pointer before dereference
The function disable_outputs() and
drm_atomic_helper_commit_modeset_enables() tries to retrieve
helper_private from the target CRTC, for dereferencing some operations.
However, the current implementation does not check whether
helper_private is null and, if not, if it has a valid pointer to a dpms
and commit functions. This commit adds pointer validations before
trying to dereference the dpms and commit function.

Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
---
drivers/gpu/drm/drm_atomic_helper.c | 30 ++++++++++++++++-------------
1 file changed, 17 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 540a77a2ade9..fbeef7c461fc 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -1028,14 +1028,16 @@ disable_outputs(struct drm_device *dev, struct drm_atomic_state *old_state)


/* Right function depends upon target state. */
- if (new_crtc_state->enable && funcs->prepare)
- funcs->prepare(crtc);
- else if (funcs->atomic_disable)
- funcs->atomic_disable(crtc, old_crtc_state);
- else if (funcs->disable)
- funcs->disable(crtc);
- else
- funcs->dpms(crtc, DRM_MODE_DPMS_OFF);
+ if (funcs) {
+ if (new_crtc_state->enable && funcs->prepare)
+ funcs->prepare(crtc);
+ else if (funcs->atomic_disable)
+ funcs->atomic_disable(crtc, old_crtc_state);
+ else if (funcs->disable)
+ funcs->disable(crtc);
+ else if (funcs->dpms)
+ funcs->dpms(crtc, DRM_MODE_DPMS_OFF);
+ }

if (!(dev->irq_enabled && dev->num_crtcs))
continue;
@@ -1277,11 +1279,13 @@ void drm_atomic_helper_commit_modeset_enables(struct drm_device *dev,
if (new_crtc_state->enable) {
DRM_DEBUG_ATOMIC("enabling [CRTC:%d:%s]\n",
crtc->base.id, crtc->name);
-
- if (funcs->atomic_enable)
- funcs->atomic_enable(crtc, old_crtc_state);
- else
- funcs->commit(crtc);
+ if (funcs) {
+ if (funcs->atomic_enable)
+ funcs->atomic_enable(crtc,
+ old_crtc_state);
+ else if (funcs->atomic_enable)
+ funcs->commit(crtc);
+ }
}
}

--
2.21.0
\
 
 \ /
  Last update: 2019-03-11 22:03    [W:0.047 / U:0.428 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site