[PATCH] drm_edid-load: Fix a missing-check bug in drivers/gpu/drm/drm_edid_load.c

From: Gen Zhang
Date: Wed May 22 2019 - 08:42:16 EST


In drm_load_edid_firmware(), fwstr is allocated by kstrdup(). And fwstr
is dereferenced in the following codes. However, memory allocation
functions such as kstrdup() may fail and returns NULL. Dereferencing
this null pointer may cause the kernel go wrong. Thus we should check
this kstrdup() operation.
Further, if kstrdup() returns NULL, we should return ERR_PTR(-ENOMEM) to
the caller site.

Signed-off-by: Gen Zhang <blackgod016574@xxxxxxxxx>

---
diff --git a/drivers/gpu/drm/drm_edid_load.c b/drivers/gpu/drm/drm_edid_load.c
index a491509..a0e107a 100644
--- a/drivers/gpu/drm/drm_edid_load.c
+++ b/drivers/gpu/drm/drm_edid_load.c
@@ -290,6 +290,8 @@ struct edid *drm_load_edid_firmware(struct drm_connector *connector)
* the last one found one as a fallback.
*/
fwstr = kstrdup(edid_firmware, GFP_KERNEL);
+ if (!fwstr)
+ return ERR_PTR(-ENOMEM);
edidstr = fwstr;

while ((edidname = strsep(&edidstr, ","))) {
---