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

4 files changed, 22 insertions, 16 deletions

diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index cf62b05e296..6848788a13d 100644
--- a/fs/9p/v9fs.c
+++ b/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:
diff --git a/net/9p/client.c b/net/9p/client.c
index a2e2d61b903..cbe066966b3 100644
--- a/net/9p/client.c
+++ b/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;
 }
 
diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c
index be1cb909d8c..31d0b05582a 100644
--- a/net/9p/trans_fd.c
+++ b/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;
 }
 
diff --git a/net/9p/trans_rdma.c b/net/9p/trans_rdma.c
index 65cb29db03f..2c95a89c0f4 100644
--- a/net/9p/trans_rdma.c
+++ b/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;
 }