From ce814ad4bb52bfc7c0472e6da0aa742ab88f4361 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Mon, 14 Dec 2020 12:54:47 +0100
Subject: [PATCH] media: allegro: Fix use after free on error
The "channel" is added to the "dev->channels" but then if
v4l2_m2m_ctx_init() fails then we free "channel" but it's still on the
list so it could lead to a use after free. Let's not add it to the
list until after v4l2_m2m_ctx_init() succeeds.
Fixes: cc62c74749a3 ("media: allegro: add missed checks in allegro_open()")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Michael Tretter <m.tretter@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
drivers/staging/media/allegro-dvt/allegro-core.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/staging/media/allegro-dvt/allegro-core.c b/drivers/staging/media/allegro-dvt/allegro-core.c
index 9f718f43282bc..640451134072b 100644
--- a/drivers/staging/media/allegro-dvt/allegro-core.c
+++ b/drivers/staging/media/allegro-dvt/allegro-core.c
@@ -2483,8 +2483,6 @@ static int allegro_open(struct file *file)
INIT_LIST_HEAD(&channel->buffers_reference);
INIT_LIST_HEAD(&channel->buffers_intermediate);
- list_add(&channel->list, &dev->channels);
-
channel->fh.m2m_ctx = v4l2_m2m_ctx_init(dev->m2m_dev, channel,
allegro_queue_init);
@@ -2493,6 +2491,7 @@ static int allegro_open(struct file *file)
goto error;
}
+ list_add(&channel->list, &dev->channels);
file->private_data = &channel->fh;
v4l2_fh_add(&channel->fh);
--
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