The copy_to/from_user() functions return the number of bytes remaining to be copied but we should return -EFAULT to the user. Fixes: f05c83e77460 ("drm/msm: add uapi to get/set debug name") Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> --- If I were reviewing this patch, I would be suspicous that we don't return immediately after the first copy_from_user() fails but I'm fairly sure that is the correct behavior. drivers/gpu/drm/msm/msm_drv.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c index b871e2e98129..1d4426cb260d 100644 --- a/drivers/gpu/drm/msm/msm_drv.c +++ b/drivers/gpu/drm/msm/msm_drv.c @@ -851,8 +851,9 @@ static int msm_ioctl_gem_info(struct drm_device *dev, void *data, ret = -EINVAL; break; } - ret = copy_from_user(msm_obj->name, - u64_to_user_ptr(args->value), args->len); + if (copy_from_user(msm_obj->name, u64_to_user_ptr(args->value), + args->len)) + ret = -EFAULT; msm_obj->name[args->len] = '\0'; for (i = 0; i < args->len; i++) { if (!isprint(msm_obj->name[i])) { @@ -868,8 +869,9 @@ static int msm_ioctl_gem_info(struct drm_device *dev, void *data, } args->len = strlen(msm_obj->name); if (args->value) { - ret = copy_to_user(u64_to_user_ptr(args->value), - msm_obj->name, args->len); + if (copy_to_user(u64_to_user_ptr(args->value), + msm_obj->name, args->len)) + ret = -EFAULT; } break; } -- 2.17.1