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Subject: Re: [PATCH] cfg80211: fix double-free after changing network
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From:   "=?UTF-8?Q?Stefan_B=c3=bchler?=" 
        <stefan.buehler@tik.uni-stuttgart.de>
To:     Johannes Berg <johannes@sipsolutions.net>
Cc:     linux-wireless@vger.kernel.org,
        =?UTF-8?Q?Stefan_B=c3=bchler?= <source@stbuehler.de>
References: <20191126100543.782023-1-stefan.buehler@tik.uni-stuttgart.de>
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Message-ID: <22d78eff-9975-e2eb-5093-b19f93831bce@tik.uni-stuttgart.de>
Date:   Wed, 4 Dec 2019 09:26:35 +0100
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In-Reply-To: <20191126100543.782023-1-stefan.buehler@tik.uni-stuttgart.de>
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Sender: linux-wireless-owner@vger.kernel.org
Precedence: bulk

Hi,

On 11/26/19 11:05 AM, Stefan Bühler wrote:
> From: Stefan Bühler <source@stbuehler.de>
> 
> If wdev->wext.keys was initialized it didn't get reset to NULL on
> unregister (and it doesn't get set in cfg80211_init_wdev either), but
> wdev is reused if unregister was triggered through
> cfg80211_switch_netns.
> 
> The next unregister (for whatever reason) will try to free
> wdev->wext.keys again.
> 
> Signed-off-by: Stefan Bühler <source@stbuehler.de>
> ---
>  net/wireless/core.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/net/wireless/core.c b/net/wireless/core.c
> index 350513744575..3e25229a059d 100644
> --- a/net/wireless/core.c
> +++ b/net/wireless/core.c
> @@ -1102,6 +1102,7 @@ static void __cfg80211_unregister_wdev(struct wireless_dev *wdev, bool sync)
>  
>  #ifdef CONFIG_CFG80211_WEXT
>  	kzfree(wdev->wext.keys);
> +	wdev->wext.keys = NULL;
>  #endif
>  	/* only initialized if we have a netdev */
>  	if (wdev->netdev)
> 

Any status update for this?  Anything I can do?  Should I resubmit this
with "Cc: stable@vger.kernel.org"?

cheers,
Stefan

-- 
Stefan Bühler    Mail/xmpp: stefan.buehler@tik.uni-stuttgart.de
Netze und Kommunikationssysteme der Universität Stuttgart (NKS)
https://www.tik.uni-stuttgart.de/    Telefon: +49 711 685 60854