9p: fix option parsing

Options pointer is being moved before calling kfree() which seems
to cause problems.  This uses a separate pointer to track and free
original allocation.
Signed-off-by: Venkateswararao Jujjuri <jvrao@us.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>w

fs/9p/v9fs.c

@@ -84,7 +84,7 @@ static const match_table_t tokens = {
 
 static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 {
-	char *options;
+	char *options, *tmp_options;
 	substring_t args[MAX_OPT_ARGS];
 	char *p;
 	int option = 0;
@@ -102,9 +102,10 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 	if (!opts)
 		return 0;
 
-	options = kstrdup(opts, GFP_KERNEL);
-	if (!options)
+	tmp_options = kstrdup(opts, GFP_KERNEL);
+	if (!tmp_options)
 		goto fail_option_alloc;
+	options = tmp_options;
 
 	while ((p = strsep(&options, ",")) != NULL) {
 		int token;
@@ -194,7 +195,8 @@ static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 			continue;
 		}
 	}
-	kfree(options);
+
+	kfree(tmp_options);
 	return ret;
 
 fail_option_alloc:

net/9p/client.c

@@ -69,7 +69,7 @@ p9_client_rpc(struct p9_client *c, int8_t type, const char *fmt, ...);
 
 static int parse_opts(char *opts, struct p9_client *clnt)
 {
-	char *options;
+	char *options, *tmp_options;
 	char *p;
 	substring_t args[MAX_OPT_ARGS];
 	int option;
@@ -81,12 +81,13 @@ static int parse_opts(char *opts, struct p9_client *clnt)
 	if (!opts)
 		return 0;
 
-	options = kstrdup(opts, GFP_KERNEL);
-	if (!options) {
+	tmp_options = kstrdup(opts, GFP_KERNEL);
+	if (!tmp_options) {
 		P9_DPRINTK(P9_DEBUG_ERROR,
 				"failed to allocate copy of option string\n");
 		return -ENOMEM;
 	}
+	options = tmp_options;
 
 	while ((p = strsep(&options, ",")) != NULL) {
 		int token;
@@ -125,7 +126,7 @@ static int parse_opts(char *opts, struct p9_client *clnt)
 	}
 
 free_and_return:
-	kfree(options);
+	kfree(tmp_options);
 	return ret;
 }
 

net/9p/trans_fd.c

@@ -714,7 +714,7 @@ static int parse_opts(char *params, struct p9_fd_opts *opts)
 	char *p;
 	substring_t args[MAX_OPT_ARGS];
 	int option;
-	char *options;
+	char *options, *tmp_options;
 	int ret;
 
 	opts->port = P9_PORT;
@@ -724,12 +724,13 @@ static int parse_opts(char *params, struct p9_fd_opts *opts)
 	if (!params)
 		return 0;
 
-	options = kstrdup(params, GFP_KERNEL);
-	if (!options) {
+	tmp_options = kstrdup(params, GFP_KERNEL);
+	if (!tmp_options) {
 		P9_DPRINTK(P9_DEBUG_ERROR,
 				"failed to allocate copy of option string\n");
 		return -ENOMEM;
 	}
+	options = tmp_options;
 
 	while ((p = strsep(&options, ",")) != NULL) {
 		int token;
@@ -760,7 +761,8 @@ static int parse_opts(char *params, struct p9_fd_opts *opts)
 			continue;
 		}
 	}
-	kfree(options);
+
+	kfree(tmp_options);
 	return 0;
 }
 

net/9p/trans_rdma.c

@@ -166,7 +166,7 @@ static int parse_opts(char *params, struct p9_rdma_opts *opts)
 	char *p;
 	substring_t args[MAX_OPT_ARGS];
 	int option;
-	char *options;
+	char *options, *tmp_options;
 	int ret;
 
 	opts->port = P9_PORT;
@@ -177,12 +177,13 @@ static int parse_opts(char *params, struct p9_rdma_opts *opts)
 	if (!params)
 		return 0;
 
-	options = kstrdup(params, GFP_KERNEL);
-	if (!options) {
+	tmp_options = kstrdup(params, GFP_KERNEL);
+	if (!tmp_options) {
 		P9_DPRINTK(P9_DEBUG_ERROR,
 			   "failed to allocate copy of option string\n");
 		return -ENOMEM;
 	}
+	options = tmp_options;
 
 	while ((p = strsep(&options, ",")) != NULL) {
 		int token;
@@ -216,7 +217,7 @@ static int parse_opts(char *params, struct p9_rdma_opts *opts)
 	}
 	/* RQ must be at least as large as the SQ */
 	opts->rq_depth = max(opts->rq_depth, opts->sq_depth);
-	kfree(options);
+	kfree(tmp_options);
 	return 0;
 }