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

From: Nicholas A. Bellinger
Date: Mon Aug 08 2011 - 17:21:37 EST


On Mon, 2011-08-08 at 13:18 +0200, Julia Lawall wrote:
> From: Julia Lawall <julia@xxxxxxx>
>
> 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@xxxxxxx>
>
> ---
> 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@xxxxxxxxxxxxx>
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

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