drm/qxl: fix use of uninitialized variable

In function qxl_release_alloc(), when kmalloc() returns a NULL pointer,
it returns value 0 and parameter *ret is uninitialized. 0 means no error
to the callers of qxl_release_alloc(). The callers keep going and will
try to reference the uninitialized variable. This patch fixes the bug,
returning "-ENOMEM" when kmalloc() fails.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=188911

Signed-off-by: Pan Bian <bianpan2016@163.com>
[seanpaul fixed up subject prefix]
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1480777902-7648-1-git-send-email-bianpan2016@163.com

diff --git a/drivers/gpu/drm/qxl/qxl_release.c b/drivers/gpu/drm/qxl/qxl_release.c
index 50b4e522f05fe71827b2bbdc49f34f5c1407648b..e6ec845b5be09a360877e475437872f47e6672c3 100644 (file)
--- a/drivers/gpu/drm/qxl/qxl_release.c
+++ b/drivers/gpu/drm/qxl/qxl_release.c
@@ -134,7 +134,7 @@ qxl_release_alloc(struct qxl_device *qdev, int type,
        release = kmalloc(size, GFP_KERNEL);
        if (!release) {
                DRM_ERROR("Out of memory\n");
-               return 0;
+               return -ENOMEM;
        }
        release->base.ops = NULL;
        release->type = type;