Re: [PATCH] cfg80211: clear cfg80211_inform_bss() from kmemleak reports

[Johannes Berg <johannes@sipsolutions.net>]

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On Thu, 2009-09-03 at 02:11 -0400, Luis R. Rodriguez wrote:
> This was giving false positives. We use eventually free this
> through kref_put(), things are not so obvious through
> cfg80211_bss_update().
> 
> Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
> ---
>  net/wireless/scan.c |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)
> 
> diff --git a/net/wireless/scan.c b/net/wireless/scan.c
> index 19c5a9a..79f7a5d 100644
> --- a/net/wireless/scan.c
> +++ b/net/wireless/scan.c
> @@ -495,6 +495,9 @@ cfg80211_inform_bss(struct wiphy *wiphy,
>  
>  	kref_init(&res->ref);
>  
> +	/* cfg80211_bss_update() eats up res - we ensure we free it there */
> +	kmemleak_ignore(res);
> +
>  	res = cfg80211_bss_update(wiphy_to_dev(wiphy), res, 0);
>  	if (!res)
>  		return NULL;

That's not making sense. cfg80211_bss_update() doesn't actually take a
reference, it adds a new one for itself and then we return one to the
caller. Why can it not track this?

Actually it looks like we do leak one in net/mac80211/ibss.c.

johannes

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