drm/radeon: fix a possible null pointer dereference

[ Upstream commit a2b28708b6 ]

In radeon_fp_native_mode(), the return value of drm_mode_duplicate()
is assigned to mode, which will lead to a NULL pointer dereference
on failure of drm_mode_duplicate(). Add a check to avoid npd.

The failure status of drm_cvt_mode() on the other path is checked too.

Signed-off-by: Gong Yuanjun <ruc_gongyuanjun@163.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Gong Yuanjun 2022-05-17 17:57:00 +08:00 committed by Greg Kroah-Hartman
parent 3e57686830
commit fee8ae0a0b

View file

@ -473,6 +473,8 @@ static struct drm_display_mode *radeon_fp_native_mode(struct drm_encoder *encode
native_mode->vdisplay != 0 &&
native_mode->clock != 0) {
mode = drm_mode_duplicate(dev, native_mode);
if (!mode)
return NULL;
mode->type = DRM_MODE_TYPE_PREFERRED | DRM_MODE_TYPE_DRIVER;
drm_mode_set_name(mode);
@ -487,6 +489,8 @@ static struct drm_display_mode *radeon_fp_native_mode(struct drm_encoder *encode
* simpler.
*/
mode = drm_cvt_mode(dev, native_mode->hdisplay, native_mode->vdisplay, 60, true, false, false);
if (!mode)
return NULL;
mode->type = DRM_MODE_TYPE_PREFERRED | DRM_MODE_TYPE_DRIVER;
DRM_DEBUG_KMS("Adding cvt approximation of native panel mode %s\n", mode->name);
}