linux-kernel - [PATCH] media: videobuf2-core: Fix error handling when fileio is deallocated

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]

Message-ID: <20181112004951.GA3948@myunghoj-Precision-5530>
Date:   Sun, 11 Nov 2018 16:49:53 -0800
From:   Myungho Jung <mhjungk@...il.com>
To:     pawel@...iak.com, m.szyprowski@...sung.com,
        kyungmin.park@...sung.com, mchehab@...nel.org
Cc:     linux-media@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] media: videobuf2-core: Fix error handling when fileio is
 deallocated

The mutex that is held from vb2_fop_read() can be unlocked while waiting
for a buffer if the queue is streaming and blocking. Meanwhile, fileio
can be released. So, it should return an error if the fileio address is
changed.

Signed-off-by: Myungho Jung <mhjungk@...il.com>
Reported-by: syzbot+4180ff9ca6810b06c1e9@...kaller.appspotmail.com
---
 drivers/media/common/videobuf2/videobuf2-core.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index 975ff5669f72..bff94752eb27 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -2564,6 +2564,10 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
 		dprintk(5, "vb2_dqbuf result: %d\n", ret);
 		if (ret)
 			return ret;
+		if (fileio != q->fileio) {
+			dprintk(3, "fileio deallocated\n");
+			return -EFAULT;
+		}
 		fileio->dq_count += 1;
 
 		fileio->cur_index = index;
-- 
2.17.1