From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: [PATCH AUTOSEL 4.19 53/60] drm: return -EFAULT if copy_to_user() fails Date: Wed, 26 Jun 2019 20:36:08 -0400 Message-ID: <20190627003616.20767-53-sashal@kernel.org> References: <20190627003616.20767-1-sashal@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190627003616.20767-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Dan Carpenter , Sean Paul , Sasha Levin , dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org From: Dan Carpenter [ Upstream commit 74b67efa8d7b4f90137f0ab9a80dd319da050350 ] 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 Signed-off-by: Sean Paul Link: https://patchwork.freedesktop.org/patch/msgid/20190618131843.GA29463@mwanda Signed-off-by: Sasha Levin --- 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 e2f775d1c112..21bec4548092 100644 --- a/drivers/gpu/drm/drm_bufs.c +++ b/drivers/gpu/drm/drm_bufs.c @@ -1321,7 +1321,10 @@ 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 67b1fca39aa6..138680b37c70 100644 --- a/drivers/gpu/drm/drm_ioc32.c +++ b/drivers/gpu/drm/drm_ioc32.c @@ -372,7 +372,10 @@ 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