Received-SPF: pass (google.com: domain of linux-kernel+bounces-12840-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
Message-ID: <7203d3fc-f1e4-4fb1-8dd3-068b0ec6c752@web.de>
Date: Thu, 28 Dec 2023 21:01:49 +0100
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
To: v9fs@lists.linux.dev, kernel-janitors@vger.kernel.org,
 =?UTF-8?Q?Christian_Sch=C3=B6nebeck?= <linux_oss@crudebyte.com>,
 Dominique Martinet <asmadeus@codewreck.org>,
 Eric Van Hensbergen <ericvh@kernel.org>, Latchesar Ionkov <lucho@ionkov.net>
Content-Language: en-GB
From: Markus Elfring <Markus.Elfring@web.de>
Subject: [PATCH] fs/9p: Improve exception handling in v9fs_session_init()
Cc: LKML <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
UI-OutboundReport: notjunk:1;M01:P0:0jWWBk4hVZo=;RRSYg94h3fJJARj0fM8mFORlhrk
 lCbDc1wENsZKRDW748d//lEXloj2bQQW0EFYtsshQuaaxz6vIxB/TIgPEUR/df2LPfBLVFjP3
 +QkmwH7q1p2ObRo4QY145HtZ0zoBCzahVL6jBDJ1ppLVlQqirVJLEusJGyHayL/KA92Mcj8RW
 mNCsJYOoo3d/GgcHkbc/agReX2KkJvb75XLiqmI2N4yOE65ge7SK/WPgZ0daUwVvPIncxvaaf
 0Y2OWhsxyjZ1gRvtXE1jBsMpdcS0XjDGoBV610ykqv4GCqgZMu3cTjDc4B1RvGFa7k4NNNTgu
 Q/C2vwOkO0gI5dE6wWEBzWzzMNWzpYlnAOem4yi4/SmIkOcv6ZLuQw2L0XUFTF/4LWvXcYyCr
 8P6TYmYfOBbv5qHfsGKKfFjJKpcgs4eHNrk7fSJ9m19Tab9Wjak3kDfv6b9FQRi6bskPKXuHI
 a+WZx9rg23UMOuJGMjucsY4OND5NsQQ4z3dfoZ/YANLmD6hQ6sk3HZlrSQ87+YiGaaZ76ZhHU
 pgYRAf2AhVQezbhDsNzps6M6ORS12FBYwYEjq9I2rK55ueRu3MQeQtAYupQzlpHXphY4WPkHk
 mMnELKelutd7UVx6hbicm2lGJPYswRfSlH5Gvf55O1pq3O25mIKHGd4mlGRdF7YikTPYfpgb/
 YbkbgxL6kLUvHoC4Qhcxcb0sXixB961FcKTXUWRStWqhTP/zzPQsKfDTltSKeDGfI9oRZfRm/
 YnF8ZDxzlPh4VX7PdDh0dJ39xuonDuxK2CB/nfn2AlZTURXKUoNJtRxpVbKS1aCoSC8S9CBWV
 THqVGEhLwrby/61/9Bi3VY4gUazqRU7Egh/yefnM3pCxx8f2YPYGw0ZZGN0miJn8vbsKM/+lk
 NI/qmQ+gwIpP2Mze2c3qE2F1IPX7AFQc7UW9UK5WmmNEViPclpyeknwzQHYk5EtArOoqTpI8j
 6iHvtFCs5c9K3OOzckqSv10TxVQ=

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Thu, 28 Dec 2023 20:47:18 +0100

The kfree() function was called in up to two cases by
the v9fs_session_init() function during error handling
even if the passed variable contained a null pointer.
This issue was detected by using the Coccinelle software.

* Thus return directly after a call of the function =E2=80=9Ckstrdup=E2=80=
=9D failed
  at the beginning.

* Adjust jump targets.

* Delete an initialisation (for the variable =E2=80=9Crc=E2=80=9D)
  which became unnecessary with this refactoring.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
=2D--
 fs/9p/v9fs.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index 61dbe52bb3a3..874a36303b72 100644
=2D-- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -392,15 +392,18 @@ struct p9_fid *v9fs_session_init(struct v9fs_session=
_info *v9ses,
 		  const char *dev_name, char *data)
 {
 	struct p9_fid *fid;
-	int rc =3D -ENOMEM;
+	int rc;

 	v9ses->uname =3D kstrdup(V9FS_DEFUSER, GFP_KERNEL);
 	if (!v9ses->uname)
-		goto err_names;
+		return ERR_PTR(-ENOMEM);

 	v9ses->aname =3D kstrdup(V9FS_DEFANAME, GFP_KERNEL);
-	if (!v9ses->aname)
-		goto err_names;
+	if (!v9ses->aname) {
+		rc =3D -ENOMEM;
+		goto free_uname;
+	}
+
 	init_rwsem(&v9ses->rename_sem);

 	v9ses->uid =3D INVALID_UID;
@@ -489,8 +492,9 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_i=
nfo *v9ses,
 #endif
 	p9_client_destroy(v9ses->clnt);
 err_names:
-	kfree(v9ses->uname);
 	kfree(v9ses->aname);
+free_uname:
+	kfree(v9ses->uname);
 	return ERR_PTR(rc);
 }

=2D-
2.43.0