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authorZhaowei Yuan <zhaowei.yuan@samsung.com>2014-06-18 14:33:59 +0800
committerDave Airlie <airlied@redhat.com>2014-06-25 13:26:57 +1000
commit1539fb9bd405ee32282ea0a38404f9e008ac5b7a (patch)
tree80d834baf72aa0f9b205c24528403a5eb69a3581
parenta497c3ba1d97fc69c1e78e7b96435ba8c2cb42ee (diff)
downloadlinux-1539fb9bd405ee32282ea0a38404f9e008ac5b7a.tar.gz
drm: fix NULL pointer access by wrong ioctl
If user uses wrong ioctl command with _IOC_NONE and argument size
greater than 0, it can cause NULL pointer access from memset of line
463. If _IOC_NONE, don't memset to 0 for kdata.

Signed-off-by: Zhaowei Yuan <zhaowei.yuan@samsung.com>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
-rwxr-xr-x[-rw-r--r--]drivers/gpu/drm/drm_drv.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 03711d00aaae..8218078b6133 100644..100755
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -419,8 +419,9 @@ long drm_ioctl(struct file *filp,
 			retcode = -EFAULT;
 			goto err_i1;
 		}
-	} else
+	} else if (cmd & IOC_OUT) {
 		memset(kdata, 0, usize);
+	}
 
 	if (ioctl->flags & DRM_UNLOCKED)
 		retcode = func(dev, kdata, file_priv);