3.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Zhaowei Yuan <zhaowei.yuan@xxxxxxxxxxx> commit 1539fb9bd405ee32282ea0a38404f9e008ac5b7a upstream. 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@xxxxxxxxxxx> Reviewed-by: David Herrmann <dh.herrmann@xxxxxxxxx> Signed-off-by: Dave Airlie <airlied@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/drm_drv.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- 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); -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html