From:   Jiasheng Jiang <jiasheng@iscas.ac.cn>
To:     hverkuil@xs4all.nl, dwlsalmeida@gmail.com, mchehab@kernel.org
Cc:     linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jiasheng Jiang <jiasheng@iscas.ac.cn>
Subject: [PATCH v3] media: vidtv: Check for null return of vzalloc
Date:   Fri, 14 Jan 2022 14:28:40 +0800
Message-Id: <20220114062840.1246544-1-jiasheng@iscas.ac.cn>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

As the possible failure of the vzalloc(), e->encoder_buf might be NULL.
Therefore, it should be better to check it in order
to guarantee the success of the initialization.
If fails, we need to free not only 'e' but also 'e->name'.
Also, if the allocation for ctx fails, we need to free 'e->encoder_buf'
else.

Fixes: f90cf6079bf6 ("media: vidtv: add a bridge driver")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
---
Changelog

v1 -> v2

* Change 1. Add 'kfree(e->name)' if fails.

v2 -> v3

* Change 1. Fix the potential memory leak if ctx fails.
* Change 2. Use goto to instead of duplicating kfree()s.
---
 drivers/media/test-drivers/vidtv/vidtv_s302m.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/media/test-drivers/vidtv/vidtv_s302m.c b/drivers/media/test-drivers/vidtv/vidtv_s302m.c
index d79b65854627..4676083cee3b 100644
--- a/drivers/media/test-drivers/vidtv/vidtv_s302m.c
+++ b/drivers/media/test-drivers/vidtv/vidtv_s302m.c
@@ -455,6 +455,9 @@ struct vidtv_encoder
 		e->name = kstrdup(args.name, GFP_KERNEL);
 
 	e->encoder_buf = vzalloc(VIDTV_S302M_BUF_SZ);
+	if (!e->encoder_buf)
+		goto out_kfree_e;
+
 	e->encoder_buf_sz = VIDTV_S302M_BUF_SZ;
 	e->encoder_buf_offset = 0;
 
@@ -467,10 +470,8 @@ struct vidtv_encoder
 	e->is_video_encoder = false;
 
 	ctx = kzalloc(priv_sz, GFP_KERNEL);
-	if (!ctx) {
-		kfree(e);
-		return NULL;
-	}
+	if (!ctx)
+		goto out_kfree_buf;
 
 	e->ctx = ctx;
 	ctx->last_duration = 0;
@@ -498,6 +499,14 @@ struct vidtv_encoder
 	e->next = NULL;
 
 	return e;
+
+out_kfree_buf:
+	kfree(e->encoder_buf);
+
+out_kfree_e:
+	kfree(e->name);
+	kfree(e);
+	return NULL;
 }
 
 void vidtv_s302m_encoder_destroy(struct vidtv_encoder *e)
-- 
2.25.1