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Message-ID: <adff8812a50ca03f22fd0b3573a19ca42481c009.camel@sipsolutions.net>
Subject: Re: [PATCH] mwifiex: Fix three heap overflow at parsing element in
 cfg80211_ap_settings
From:   Johannes Berg <johannes@sipsolutions.net>
To:     huangwenabc@gmail.com, linux-wireless@vger.kernel.org
Cc:     amitkarwar@gmail.com, nishants@marvell.com, gbhat@marvell.com,
        huxinming820@gmail.com, solar@openwall.com, greg@kroah.com,
        kvalo@codeaurora.org, sashal@kernel.org, mrehak@redhat.com
Date:   Wed, 28 Aug 2019 22:36:58 +0200
In-Reply-To: <20190828020751.13625-1-huangwenabc@gmail.com> (sfid-20190828_040827_580483_8289AFC7)
References: <20190828020751.13625-1-huangwenabc@gmail.com>
         (sfid-20190828_040827_580483_8289AFC7)
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First of all, the subject doesn't make a lot of sense?


Secondly, for a fix the code is fine I guess, but:

>  	rate_ie = (void *)cfg80211_find_ie(WLAN_EID_EXT_SUPP_RATES,
>  					   params->beacon.tail,
>  					   params->beacon.tail_len);

consider removing struct ieee_types_header from your driver, and using
struct element from <linux/ieee80211.h> instead.

This also comes with cfg80211_find_elem() that returns a suitably typed
pointer, so you don't need any casts.

>  	if (vendor_ie) {
>  		wmm_ie = vendor_ie;
> +		if (*(wmm_ie + 1) > sizeof(struct mwifiex_types_wmm_info))
> +			return;

and using it here would be a whole lot easier to understand too :)

johannes