[PATCH AUTOSEL 5.15 38/51] drm/radeon: fix a possible null pointer dereference

[Sasha Levin]

From: Gong Yuanjun <ruc_gongyuan...@163.com>

[ Upstream commit a2b28708b645c5632dc93669ab06e97874c8244f ]

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_gongyuan...@163.com>
Signed-off-by: Alex Deucher <alexander.deuc...@amd.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/gpu/drm/radeon/radeon_connectors.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c 
b/drivers/gpu/drm/radeon/radeon_connectors.c
index 1546abcadacf..d157bb9072e8 100644
--- a/drivers/gpu/drm/radeon/radeon_connectors.c
+++ b/drivers/gpu/drm/radeon/radeon_connectors.c
@@ -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);
        }
-- 
2.35.1