From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Date: Tue, 18 Jun 2019 13:18:43 +0000 Subject: [PATCH v2] drm: return -EFAULT if copy_to_user() fails Message-Id: <20190618131843.GA29463@mwanda> List-Id: References: <20190618125623.GA24896@mwanda> In-Reply-To: <20190618125623.GA24896@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Al Viro Cc: Maxime Ripard , kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, David Airlie , Sean Paul The copy_from_user() function returns the number of bytes remaining to be copied but we want to return a negative error code. Otherwise the callers treat it as a successful copy. Signed-off-by: Dan Carpenter --- v2: The first version was missing a chunk drivers/gpu/drm/drm_bufs.c | 5 ++++- drivers/gpu/drm/drm_ioc32.c | 5 ++++- 2 files changed, 8 insertions(+), 2 deletions(-) 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, diff --git a/drivers/gpu/drm/drm_ioc32.c b/drivers/gpu/drm/drm_ioc32.c index 586aa28024c5..a16b6dc2fa47 100644 --- a/drivers/gpu/drm/drm_ioc32.c +++ b/drivers/gpu/drm/drm_ioc32.c @@ -378,7 +378,10 @@ static int copy_one_buf32(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 + count, &v, offsetof(drm_buf_desc32_t, flags)); + + if (copy_to_user(to + count, &v, offsetof(drm_buf_desc32_t, flags))) + return -EFAULT; + return 0; } static int drm_legacy_infobufs32(struct drm_device *dev, void *data, -- 2.20.1