The copy_to_user() function returns the number of bytes remaining to be copied, but we want to return -EFAULT. This function is called from __drm_legacy_infobufs() which expects negative error codes. Fixes: 5c7640ab6258 ("switch compat_drm_infobufs() to drm_ioctl_kernel()") Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> --- This goes through Al's tree and not through drm. Presumably this patch will just get folded into the original. drivers/gpu/drm/drm_bufs.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c index 68dacf8422c6..8ce9d73fab4f 100644 --- a/drivers/gpu/drm/drm_bufs.c +++ b/drivers/gpu/drm/drm_bufs.c @@ -1351,7 +1351,10 @@ static int copy_one_buf(void *data, int count, struct drm_buf_entry *from) .size = from->buf_size, .low_mark = from->low_mark, .high_mark = from->high_mark}; - return copy_to_user(to, &v, offsetof(struct drm_buf_desc, flags)); + + if (copy_to_user(to, &v, offsetof(struct drm_buf_desc, flags))) + return -EFAULT; + return 0; } int drm_legacy_infobufs(struct drm_device *dev, void *data, -- 2.20.1