linux-kernel - [PATCH] media:exynos4-is: Fix a use after free in isp_video

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 26 Apr 2021 19:33:15 -0700
From:   Lv Yunlong <lyl2019@...l.ustc.edu.cn>
To:     s.nawrocki@...sung.com, mchehab@...nel.org, krzk@...nel.org
Cc:     linux-media@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-samsung-soc@...r.kernel.org, linux-kernel@...r.kernel.org,
        Lv Yunlong <lyl2019@...l.ustc.edu.cn>
Subject: [PATCH] media:exynos4-is: Fix a use after free in isp_video_release

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(filp->private_data), which is a use
after free bug.

My patch set file->private_data to NULL after _vb2_fop_release()
to avoid the use after free.

Fixes: 34947b8aebe3f ("[media] exynos4-is: Add the FIMC-IS ISP capture DMA driver")
Signed-off-by: Lv Yunlong <lyl2019@...l.ustc.edu.cn>
---
 drivers/media/platform/exynos4-is/fimc-isp-video.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/media/platform/exynos4-is/fimc-isp-video.c b/drivers/media/platform/exynos4-is/fimc-isp-video.c
index 612b9872afc8..f414493258ad 100644
--- a/drivers/media/platform/exynos4-is/fimc-isp-video.c
+++ b/drivers/media/platform/exynos4-is/fimc-isp-video.c
@@ -315,6 +315,7 @@ static int isp_video_release(struct file *file)
 	}
 
 	_vb2_fop_release(file, NULL);
+	filp->private_data = NULL;
 
 	if (v4l2_fh_is_singular_file(file)) {
 		fimc_pipeline_call(&ivc->ve, close);
-- 
2.25.1