From:   Bernard Zhao <bernard@vivo.com>
To:     Paul Moore <paul@paul-moore.com>,
        Stephen Smalley <stephen.smalley.work@gmail.com>,
        Eric Paris <eparis@parisplace.org>, selinux@vger.kernel.org,
        linux-kernel@vger.kernel.org
Cc:     Bernard Zhao <bernard@vivo.com>
Subject: [PATCH] security/selinux: fix potential memleak in error branch
Date:   Wed,  1 Dec 2021 19:12:09 -0800
Message-Id: <20211202031209.253228-1-bernard@vivo.com>
Content-Transfer-Encoding: 8bit
Content-Type: text/plain
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?WGwdsaC6oAzlzSdrwmGd4FYRE/BzwBI+G7B1XgZwekUNOO7M/MI8uG8PAo4P?=
 =?us-ascii?Q?HQO4G1NOycBXSZD2q8C1S0GmiDZSpK7ujaj4aeAhhuv+0bZWMhpgkHOv6VJL?=
 =?us-ascii?Q?lKBaByJ/JUsBljjfa7gnMMjMxDbt70MRPIale7U+RP+dR8i15l3xBnldN2Mc?=
 =?us-ascii?Q?ND+bY7vKeoi34mNB6qguTxYmn5BggQgR346zQQbBIdj6cFMEkXRlcDv7yO3Q?=
 =?us-ascii?Q?ElL8dSDaCL39nJGGCigqHL1P4eGWSTkNPXduMrFBoXpVN+5xSXIzSsSJQuvn?=
 =?us-ascii?Q?hOj9WZMb5DXuzMkG6mqJXVdT7OiZredQTQJg6RhEQMplMugQ1B7PjexCb2Va?=
 =?us-ascii?Q?N+gd3d2Sm/CD1FSoepeJMmDXs/1PYoedbRI55m2MUbRpXKJnS5T7CvZTHdcb?=
 =?us-ascii?Q?B+g3oaeoF0KQx0Aj/kyyniCL3z+vFpHO8/cnJG9Rn+PsX/viwGrFrENlMnBj?=
 =?us-ascii?Q?fSzP1Cm11EMsHL5mrnyQ45yitipd0VbyswyWqZqHxHdJVorPUfLq6+62nREO?=
 =?us-ascii?Q?KBhdx79KnuqTulSoH1i4UjrFkbaNgGs7Rh17DKel/JL99H5alK+boS++nDEO?=
 =?us-ascii?Q?k69QGTZNRTKD4frIgXb9UWMRkb0O8awYRj4Ch3ah81jEnMTVk5mOxKl5A/97?=
 =?us-ascii?Q?LhYbTbTY5CA+2jHCCUW2/a8hCvCoi/micb9QVgsvvz02Lfj1ICraF5PKJc1P?=
 =?us-ascii?Q?VBdBkUr1+Sv4/luz2cH4vGyH9i7ZKUGFKTjyzJ7c+JoUNRS/Yu3sphi27q6O?=
 =?us-ascii?Q?vdORSxTBsqIP5tBDqyBHJsoU01CvFG1uXsuuUwoI10WuwkJLyYUtKGr6MtF0?=
 =?us-ascii?Q?wESSdfzq4orDMob5B0u9OKhr1LjT4c7A1VFMcI41+bCh1iO2NNELRuG/SPJm?=
 =?us-ascii?Q?O+BVCG/bmlOPebfKl1chJxxfbP/nQXg0twvUW545aaA5hTv5eJ/b1Gv1XPno?=
 =?us-ascii?Q?7tS1+/Huq8Nqpqn9nGH5koA+7udN8tLKxcpHFC79mauViq2laNzHlF81JCfn?=
 =?us-ascii?Q?jmPD9/t2gx9zs00Vi8aEyLkdZclSz/HFfloAA9CIKI0xnvC6wILxITDj5kkL?=
 =?us-ascii?Q?8/l0SvyGtWuy9Fs3liIVkmgCF36cCuWwOKEFF5rKXFJHTGhw0t2Z2I7DVvLH?=
 =?us-ascii?Q?EsQluzQSJcDY+LiQ9wl2bKplCn/7vigvp6wFrCmVmpML2HmHz67rzHxh1wrG?=
 =?us-ascii?Q?DLogaHIysCePsuZPLAHhOKVxc+0cuEclWUJxQ/JKI4hQx1++CbGnXbXJO9x9?=
 =?us-ascii?Q?3ic/drwfdRCMzK6rfvblMPkuQLtcB6sQPNLicfo6VaOv9XsoqF8R3GQTlcja?=
 =?us-ascii?Q?Q/mUuzAzfxcXDfXcRo1Gf6GiooeWG/cil2WptK7Gi/o63plTOCh7+dBj9892?=
 =?us-ascii?Q?6JfgRehVxlW7gayDq6ryiWinyymh6qvRtAOf3bs2FtOruYUK9XuMuasZw9+p?=
 =?us-ascii?Q?awkC67EA/GyGggaR5fwLlboxET58fPqN8TOL3iJvVT3D4VXR+jn0BH+Mpr7c?=
 =?us-ascii?Q?5OCLPxujd2VLSNosmnbFSX5gAmM7hWCAqlVQ4QGWsaCzPy5YLXCTrbpGkl60?=
 =?us-ascii?Q?bZi4aTMsN2ogvIIGCGM3gXBwFGJdZLJVHZzgmlF2iSton2W8IMGc9lBMe0dV?=
 =?us-ascii?Q?j8aIrO63OVJrc8ktUeFjQQ0=3D?=
X-OriginatorOrg: vivo.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 8654f474-4c88-4ce8-91d8-08d9b5418d33
X-MS-Exchange-CrossTenant-AuthSource: PSAPR06MB4021.apcprd06.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 02 Dec 2021 03:12:19.8653
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 923e42dc-48d5-4cbe-b582-1a797a6412ed
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: 0tvxmXxpa86vur68skDaRpjKFTuomkWHa1E8i4byiKyd2gUY5IZWyXDjYZx4AvZcPEZ4x0CYYivRLYmnWPYiHw==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: PS1PR0601MB3690
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

This patch try to fix potential memleak in error branch.

Signed-off-by: Bernard Zhao <bernard@vivo.com>
---
 security/selinux/hooks.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 62d30c0a30c2..10700720bb74 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -983,6 +983,7 @@ static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
 static int selinux_add_opt(int token, const char *s, void **mnt_opts)
 {
 	struct selinux_mnt_opts *opts = *mnt_opts;
+	bool is_alloc_opts = false;
 
 	if (token == Opt_seclabel)	/* eaten and completely ignored */
 		return 0;
@@ -992,9 +993,13 @@ static int selinux_add_opt(int token, const char *s, void **mnt_opts)
 		if (!opts)
 			return -ENOMEM;
 		*mnt_opts = opts;
+		is_alloc_opts = true;
 	}
-	if (!s)
+	if (!s) {
+		if (is_alloc_opts)
+			kfree(opts);
 		return -ENOMEM;
+	}
 	switch (token) {
 	case Opt_context:
 		if (opts->context || opts->defcontext)
@@ -1020,6 +1025,8 @@ static int selinux_add_opt(int token, const char *s, void **mnt_opts)
 	return 0;
 Einval:
 	pr_warn(SEL_MOUNT_FAIL_MSG);
+	if (is_alloc_opts)
+		kfree(opts);
 	return -EINVAL;
 }
 
-- 
2.33.1