[PATCH 7/9] drivers/target/iscsi/iscsi_target_parameters.c: add missing kfree

[PATCH 7/9] drivers/target/iscsi/iscsi_target_parameters.c: add missing kfree

[Julia Lawall]

From: Julia Lawall <julia@diku.dk>

At this point, the new_param that has just been allocated has not been
stored in the list, so it and new_param->name, once it is defined, have to
be freed separately.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@exists@
local idexpression x;
statement S,S1;
expression E;
identifier fl;
expression *ptr != NULL;
@@

x = \(kmalloc\|kzalloc\|kcalloc\)(...);
...
if (x = NULL) S
<... when != x
     when != if (...) { <+...kfree(x)...+> }
     when any
     when != true x = NULL
x->fl
...>
(
if (x = NULL) S1
|
if (...) { ... when != x
               when forall
(
 return \(0\|<+...x...+>\|ptr\);
|
* return ...;
)
}
)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>

---
 drivers/target/iscsi/iscsi_target_parameters.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/target/iscsi/iscsi_target_parameters.c b/drivers/target/iscsi/iscsi_target_parameters.c
index 252e246..b8dbe44 100644
--- a/drivers/target/iscsi/iscsi_target_parameters.c
+++ b/drivers/target/iscsi/iscsi_target_parameters.c
@@ -584,6 +584,7 @@ int iscsi_copy_param_list(
 		if (!new_param->name) {
 			pr_err("Unable to allocate memory for"
 				" parameter name.\n");
+			kfree(new_param);
 			goto err_out;
 		}
 
@@ -592,6 +593,8 @@ int iscsi_copy_param_list(
 		if (!new_param->value) {
 			pr_err("Unable to allocate memory for"
 				" parameter value.\n");
+			kfree(new_param->name);
+			kfree(new_param);
 			goto err_out;
 		}
 

Re: [PATCH 7/9] drivers/target/iscsi/iscsi_target_parameters.c:

[Nicholas A. Bellinger]

On Mon, 2011-08-08 at 13:18 +0200, Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>
> 
> At this point, the new_param that has just been allocated has not been
> stored in the list, so it and new_param->name, once it is defined, have to
> be freed separately.
> 
> A simplified version of the semantic match that finds this problem is as
> follows: (http://coccinelle.lip6.fr/)
> 
> // <smpl>
> @exists@
> local idexpression x;
> statement S,S1;
> expression E;
> identifier fl;
> expression *ptr != NULL;
> @@
> 
> x = \(kmalloc\|kzalloc\|kcalloc\)(...);
> ...
> if (x = NULL) S
> <... when != x
>      when != if (...) { <+...kfree(x)...+> }
>      when any
>      when != true x = NULL
> x->fl
> ...>
> (
> if (x = NULL) S1
> |
> if (...) { ... when != x
>                when forall
> (
>  return \(0\|<+...x...+>\|ptr\);
> |
> * return ...;
> )
> }
> )
> // </smpl>
> 
> Signed-off-by: Julia Lawall <julia@diku.dk>
> 
> ---
>  drivers/target/iscsi/iscsi_target_parameters.c |    3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/target/iscsi/iscsi_target_parameters.c b/drivers/target/iscsi/iscsi_target_parameters.c
> index 252e246..b8dbe44 100644
> --- a/drivers/target/iscsi/iscsi_target_parameters.c
> +++ b/drivers/target/iscsi/iscsi_target_parameters.c
> @@ -584,6 +584,7 @@ int iscsi_copy_param_list(
>  		if (!new_param->name) {
>  			pr_err("Unable to allocate memory for"
>  				" parameter name.\n");
> +			kfree(new_param);
>  			goto err_out;
>  		}
>  
> @@ -592,6 +593,8 @@ int iscsi_copy_param_list(
>  		if (!new_param->value) {
>  			pr_err("Unable to allocate memory for"
>  				" parameter value.\n");
> +			kfree(new_param->name);
> +			kfree(new_param);
>  			goto err_out;
>  		}
>  
> 

Hi Julia,

Jesper and Dan already caught this one last week, and has been resolved
with the following patch in lio-core-2.6.git:

commit 83f8b803171751082174162cd1fa058c67d579ab
Author: Jesper Juhl <jj@chaosbits.net>
Date:   Tue Aug 2 10:26:36 2011 +0200

    iscsi-target: Fix leak on failure in iscsi_copy_param_list()

This one is being queued for the next round of target fixes for
mainline.

Thanks for reporting!

--nab