From: Lv Yunlong lyl2019@mail.ustc.edu.cn
[ Upstream commit 01fe904c9afd26e79c1f73aa0ca2e3d785e5e319 ]
In isp_video_release, file->private_data is freed via _vb2_fop_release()->v4l2_fh_release(). But the freed file->private_data is still used in v4l2_fh_is_singular_file() ->v4l2_fh_is_singular(file->private_data), which is a use after free bug.
My patch uses a variable 'is_singular_file' to avoid the uaf. v3: https://lore.kernel.org/patchwork/patch/1419058/
Fixes: 34947b8aebe3f ("[media] exynos4-is: Add the FIMC-IS ISP capture DMA driver") Signed-off-by: Lv Yunlong lyl2019@mail.ustc.edu.cn Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl Signed-off-by: Mauro Carvalho Chehab mchehab+huawei@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/media/platform/exynos4-is/fimc-isp-video.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/media/platform/exynos4-is/fimc-isp-video.c b/drivers/media/platform/exynos4-is/fimc-isp-video.c index 39340abefd14..c9ef74ee476a 100644 --- a/drivers/media/platform/exynos4-is/fimc-isp-video.c +++ b/drivers/media/platform/exynos4-is/fimc-isp-video.c @@ -308,17 +308,20 @@ static int isp_video_release(struct file *file) struct fimc_is_video *ivc = &isp->video_capture; struct media_entity *entity = &ivc->ve.vdev.entity; struct media_device *mdev = entity->graph_obj.mdev; + bool is_singular_file;
mutex_lock(&isp->video_lock);
- if (v4l2_fh_is_singular_file(file) && ivc->streaming) { + is_singular_file = v4l2_fh_is_singular_file(file); + + if (is_singular_file && ivc->streaming) { media_pipeline_stop(entity); ivc->streaming = 0; }
_vb2_fop_release(file, NULL);
- if (v4l2_fh_is_singular_file(file)) { + if (is_singular_file) { fimc_pipeline_call(&ivc->ve, close);
mutex_lock(&mdev->graph_mutex);