[PATCH] of: avoid format string parsing in kobject names

[PATCH] of: avoid format string parsing in kobject names

[Kees Cook]

This makes sure a format string cannot leak into the kobject name that
is constructed. (And splits the >80 character line.)

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/of/base.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 8368d96ae7b4..f27d922eaece 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -227,7 +227,8 @@ static int __of_node_add(struct device_node *np)
 	np->kobj.kset = of_kset;
 	if (!np->parent) {
 		/* Nodes without parents are new top level trees */
-		rc = kobject_add(&np->kobj, NULL, safe_name(&of_kset->kobj, "base"));
+		rc = kobject_add(&np->kobj, NULL, "%s",
+				 safe_name(&of_kset->kobj, "base"));
 	} else {
 		name = safe_name(&np->parent->kobj, kbasename(np->full_name));
 		if (!name || !name[0])
-- 
1.7.9.5


-- 
Kees Cook
Chrome OS Security

Re: [PATCH] of: avoid format string parsing in kobject names

[Rob Herring]

On Tue, Jun 10, 2014 at 11:57 AM, Kees Cook <keescook@chromium.org> wrote:
> This makes sure a format string cannot leak into the kobject name that
> is constructed. (And splits the >80 character line.)
>
> Signed-off-by: Kees Cook <keescook@chromium.org>

Applied.

This seems like a non-obvious thing to do, but I guess most people
aren't dealing directly with kobjects.

Rob

> ---
>  drivers/of/base.c |    3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 8368d96ae7b4..f27d922eaece 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -227,7 +227,8 @@ static int __of_node_add(struct device_node *np)
>         np->kobj.kset = of_kset;
>         if (!np->parent) {
>                 /* Nodes without parents are new top level trees */
> -               rc = kobject_add(&np->kobj, NULL, safe_name(&of_kset->kobj, "base"));
> +               rc = kobject_add(&np->kobj, NULL, "%s",
> +                                safe_name(&of_kset->kobj, "base"));
>         } else {
>                 name = safe_name(&np->parent->kobj, kbasename(np->full_name));
>                 if (!name || !name[0])
> --
> 1.7.9.5
>
>
> --
> Kees Cook
> Chrome OS Security

Re: [PATCH] of: avoid format string parsing in kobject names

[Kees Cook]

On Fri, Jun 13, 2014 at 7:55 AM, Rob Herring <robherring2@gmail.com> wrote:
> On Tue, Jun 10, 2014 at 11:57 AM, Kees Cook <keescook@chromium.org> wrote:
>> This makes sure a format string cannot leak into the kobject name that
>> is constructed. (And splits the >80 character line.)
>>
>> Signed-off-by: Kees Cook <keescook@chromium.org>
>
> Applied.
>
> This seems like a non-obvious thing to do, but I guess most people
> aren't dealing directly with kobjects.

Yeah, it's really unlikely this could get reached, but I just keep
cleaning this up any time I see them just to be safe. :)

Thanks!

-Kees


-- 
Kees Cook
Chrome OS Security