Re: [PATCH 4/4] arch/powerpc/platforms/chrp/nvram.c: Addof_node_put to avoid memory leak

From: Grant Likely
Date: Wed Sep 08 2010 - 16:00:25 EST


On Tue, Aug 31, 2010 at 05:48:58PM +0200, Julia Lawall wrote:
> Add a call to of_node_put in the error handling code following a call to
> of_find_node_by_type.
>
> The semantic match that finds this problem is as follows:
> (http://coccinelle.lip6.fr/)
>
> // <smpl>
> @r exists@
> local idexpression x;
> expression E,E1,E2;
> statement S;
> @@
>
> *x =
> (of_find_node_by_path
> |of_find_node_by_name
> |of_find_node_by_phandle
> |of_get_parent
> |of_get_next_parent
> |of_get_next_child
> |of_find_compatible_node
> |of_match_node
> |of_find_node_by_type
> |of_find_node_with_property
> |of_find_matching_node
> |of_parse_phandle
> )(...);
> ...
> if (x == NULL) S
> <... when != x = E
> *if (...) {
> ... when != of_node_put(x)
> when != if (...) { ... of_node_put(x); ... }
> (
> return <+...x...+>;
> |
> * return ...;
> )
> }
> ...>
> (
> E2 = x;
> |
> of_node_put(x);
> )
> // </smpl>
>
> Signed-off-by: Julia Lawall <julia@xxxxxxx>

Acked-by: Grant Likely <grant.likely@xxxxxxxxxxxx>

>
> ---
> arch/powerpc/platforms/chrp/nvram.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/platforms/chrp/nvram.c b/arch/powerpc/platforms/chrp/nvram.c
> index ba3588f..d3ceff0 100644
> --- a/arch/powerpc/platforms/chrp/nvram.c
> +++ b/arch/powerpc/platforms/chrp/nvram.c
> @@ -74,8 +74,10 @@ void __init chrp_nvram_init(void)
> return;
>
> nbytes_p = of_get_property(nvram, "#bytes", &proplen);
> - if (nbytes_p == NULL || proplen != sizeof(unsigned int))
> + if (nbytes_p == NULL || proplen != sizeof(unsigned int)) {
> + of_node_put(nvram);
> return;
> + }
>
> nvram_size = *nbytes_p;
>
>
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