intel, gma500, lvds: Fix use after free and mem leak in psb_intel_lvds_init()

In psb_intel_lvds_init(), if we fail to allocate memory for
'psb_intel_connector' we free the memory we previously allocated for
'psb_intel_encoder', but we then proceed to use that free'd pointer
when we do 'psb_intel_encoder->dev_priv = lvds_priv;'.

We may also leak the memory we allocated for 'psb_intel_encoder' if we
'goto failed_connector;' and the variable goes out of scope.

While I was there anyway, I also removed the pointless 'if
(psb_intel_connector)' before freeing it at the 'failed_connector:'
label - kfree() deals gracefully with NULL pointers, so it is not
needed.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 4 insertions, 5 deletions

diff --git a/drivers/gpu/drm/gma500/psb_intel_lvds.c b/drivers/gpu/drm/gma500/psb_intel_lvds.c
index 69a96513752f..c83f5b5d1057 100644
--- a/drivers/gpu/drm/gma500/psb_intel_lvds.c
+++ b/drivers/gpu/drm/gma500/psb_intel_lvds.c
@@ -713,7 +713,6 @@ void psb_intel_lvds_init(struct drm_device *dev,
 
         psb_intel_encoder =
                         kzalloc(sizeof(struct psb_intel_encoder), GFP_KERNEL);
-
         if (!psb_intel_encoder) {
                 dev_err(dev->dev, "psb_intel_encoder allocation error\n");
                 return;
@@ -721,10 +720,9 @@ void psb_intel_lvds_init(struct drm_device *dev,
 
         psb_intel_connector =
                 kzalloc(sizeof(struct psb_intel_connector), GFP_KERNEL);
-
         if (!psb_intel_connector) {
-                kfree(psb_intel_encoder);
                 dev_err(dev->dev, "psb_intel_connector allocation error\n");
+                goto failed_encoder;
         }
 
         lvds_priv = kzalloc(sizeof(struct psb_intel_lvds_priv), GFP_KERNEL);
@@ -862,7 +860,8 @@ failed_blc_i2c:
         drm_encoder_cleanup(encoder);
         drm_connector_cleanup(connector);
 failed_connector:
-        if (psb_intel_connector)
-                kfree(psb_intel_connector);
+        kfree(psb_intel_connector);
+failed_encoder:
+        kfree(psb_intel_encoder);
 }