drm/msm: Truncate the buffer object name if the copy from user failed

(Resend since there was a compile error that I forgot to commit before sending)

If there is a error while doing a copy_from_user() for MSM_INFO_SET_NAME
make sure to truncate the object name so that there isn't a chance that
we'll have random data in the string.

This is on top of [1] reported and fixed by Dan Carpenter.

[1] https://patchwork.freedesktop.org/series/56656/

Fixes: f05c83e77460 ("drm/msm: add uapi to get/set debug name")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 87eae44..906b2bb 100644 (file)
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -852,8 +852,11 @@ static int msm_ioctl_gem_info(struct drm_device *dev, void *data,
                        break;
                }
                if (copy_from_user(msm_obj->name, u64_to_user_ptr(args->value),
-                                  args->len))
+                                  args->len)) {
+                       msm_obj->name[0] = '\0';
                        ret = -EFAULT;
+                       break;
+               }
                msm_obj->name[args->len] = '\0';
                for (i = 0; i < args->len; i++) {
                        if (!isprint(msm_obj->name[i])) {