libceph, ceph: avoid memory leak when specifying same option several times

[ Upstream commit 937441f3 ]

When parsing string option, in order to avoid memory leak we need to
carefully free it first in case of specifying same option several times.
Signed-off-by: Chengguang Xu <cgxu519@icloud.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/ceph/super.c

@@ -224,6 +224,7 @@ static int parse_fsopt_token(char *c, void *private)
 			return -ENOMEM;
 		break;
 	case Opt_mds_namespace:
+		kfree(fsopt->mds_namespace);
 		fsopt->mds_namespace = kstrndup(argstr[0].from,
 						argstr[0].to-argstr[0].from,
 						GFP_KERNEL);
@@ -231,6 +232,7 @@ static int parse_fsopt_token(char *c, void *private)
 			return -ENOMEM;
 		break;
 	case Opt_fscache_uniq:
+		kfree(fsopt->fscache_uniq);
 		fsopt->fscache_uniq = kstrndup(argstr[0].from,
 					       argstr[0].to-argstr[0].from,
 					       GFP_KERNEL);

net/ceph/ceph_common.c

@@ -418,11 +418,15 @@ ceph_parse_options(char *options, const char *dev_name,
 				opt->flags |= CEPH_OPT_FSID;
 			break;
 		case Opt_name:
+			kfree(opt->name);
 			opt->name = kstrndup(argstr[0].from,
 					      argstr[0].to-argstr[0].from,
 					      GFP_KERNEL);
 			break;
 		case Opt_secret:
+			ceph_crypto_key_destroy(opt->key);
+			kfree(opt->key);
+
 		        opt->key = kzalloc(sizeof(*opt->key), GFP_KERNEL);
 			if (!opt->key) {
 				err = -ENOMEM;
@@ -433,6 +437,9 @@ ceph_parse_options(char *options, const char *dev_name,
 				goto out;
 			break;
 		case Opt_key:
+			ceph_crypto_key_destroy(opt->key);
+			kfree(opt->key);
+
 		        opt->key = kzalloc(sizeof(*opt->key), GFP_KERNEL);
 			if (!opt->key) {
 				err = -ENOMEM;