[PATCH v3] Fix leak indrivers/target/iscsi/iscsi_target_parameters.c::iscsi_copy_param_list()

[Jesper Juhl]

On Mon, 1 Aug 2011, Joe Perches wrote:

> On Mon, 2011-08-01 at 22:32 +0200, Jesper Juhl wrote:
> > diff --git a/drivers/target/iscsi/iscsi_target_parameters.c b/drivers/target/iscsi/iscsi_target_parameters.c
> []
> > @@ -572,6 +572,17 @@ int iscsi_copy_param_list(
> []
> > +		if (!new_param->name || !new_param->value) {
> []
> > +			pr_err("Unable to allocate memory for parameter "
> > +				"name/value.\n");
> 
> I know you didn't change these lines, but could you please
> remember to coalesce formats to a single line next time?
> 

Ok, let me try once more. I hope this is now acceptable.


From: Jesper Juhl <jj@xxxxxxxxxxxxx>
Subject: [PATCH v3] Fix leak in drivers/target/iscsi/iscsi_target_parameters.c::iscsi_copy_param_list()

We leak memory if the allocations for 'new_param->name' or
'new_param->value' fail.

We also do a lot of variable assignments that are completely pointless
if the allocations fail.

So, let's move the allocations before the assignments and also make
sure that we free whatever was allocated to one if the allocation fail.

There's also some small CodingStyle fixups in there (curly braces on
both branches of if statement, only one variable per line) since I was
in the area anyway. And finally, error messages in the function are
put on a single line for easy grep'abillity.

Signed-off-by: Jesper Juhl <jj@xxxxxxxxxxxxx>
---
 drivers/target/iscsi/iscsi_target_parameters.c |   43 +++++++++---------------
 1 files changed, 16 insertions(+), 27 deletions(-)

diff --git a/drivers/target/iscsi/iscsi_target_parameters.c b/drivers/target/iscsi/iscsi_target_parameters.c
index 252e246..497b2e7 100644
--- a/drivers/target/iscsi/iscsi_target_parameters.c
+++ b/drivers/target/iscsi/iscsi_target_parameters.c
@@ -545,13 +545,13 @@ int iscsi_copy_param_list(
 	struct iscsi_param_list *src_param_list,
 	int leading)
 {
-	struct iscsi_param *new_param = NULL, *param = NULL;
+	struct iscsi_param *param = NULL;
+	struct iscsi_param *new_param = NULL;
 	struct iscsi_param_list *param_list = NULL;
 
 	param_list = kzalloc(sizeof(struct iscsi_param_list), GFP_KERNEL);
 	if (!param_list) {
-		pr_err("Unable to allocate memory for"
-				" struct iscsi_param_list.\n");
+		pr_err("Unable to allocate memory for struct iscsi_param_list.\n");
 		goto err_out;
 	}
 	INIT_LIST_HEAD(&param_list->param_list);
@@ -567,8 +567,17 @@ int iscsi_copy_param_list(
 
 		new_param = kzalloc(sizeof(struct iscsi_param), GFP_KERNEL);
 		if (!new_param) {
-			pr_err("Unable to allocate memory for"
-				" struct iscsi_param.\n");
+			pr_err("Unable to allocate memory for struct iscsi_param.\n");
+			goto err_out;
+		}
+
+		new_param->name = kstrdup(param->name, GFP_KERNEL);
+		new_param->value = kstrdup(param->value, GFP_KERNEL);
+		if (!new_param->value || !new_param->name) {
+			kfree(new_param->value);
+			kfree(new_param->name);
+			kfree(new_param);
+			pr_err("Unable to allocate memory for parameter name/value.\n");
 			goto err_out;
 		}
 
@@ -580,32 +589,12 @@ int iscsi_copy_param_list(
 		new_param->use = param->use;
 		new_param->type_range = param->type_range;
 
-		new_param->name = kzalloc(strlen(param->name) + 1, GFP_KERNEL);
-		if (!new_param->name) {
-			pr_err("Unable to allocate memory for"
-				" parameter name.\n");
-			goto err_out;
-		}
-
-		new_param->value = kzalloc(strlen(param->value) + 1,
-				GFP_KERNEL);
-		if (!new_param->value) {
-			pr_err("Unable to allocate memory for"
-				" parameter value.\n");
-			goto err_out;
-		}
-
-		memcpy(new_param->name, param->name, strlen(param->name));
-		new_param->name[strlen(param->name)] = '\0';
-		memcpy(new_param->value, param->value, strlen(param->value));
-		new_param->value[strlen(param->value)] = '\0';
-
 		list_add_tail(&new_param->p_list, &param_list->param_list);
 	}
 
-	if (!list_empty(&param_list->param_list))
+	if (!list_empty(&param_list->param_list)) {
 		*dst_param_list = param_list;
-	else {
+	} else {
 		pr_err("No parameters allocated.\n");
 		goto err_out;
 	}
-- 
1.7.6


-- 
Jesper Juhl <jj@xxxxxxxxxxxxx>       http://www.chaosbits.net/
Don't top-post http://www.catb.org/jargon/html/T/top-post.html
Plain text mails only, please.

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