From: "John W. Linville" <linville@tuxdriver.com>
To: Dan Carpenter <error27@gmail.com>
Cc: nbd@openwrt.org, linux-wireless@vger.kernel.org,
johannes@sipsolutions.net
Subject: Re: potential null deref in minstrel_ht_update_caps()?
Date: Thu, 22 Jul 2010 15:35:43 -0400 [thread overview]
Message-ID: <20100722193543.GF2616@tuxdriver.com> (raw)
In-Reply-To: <20100722110933.GA17585@bicker>
On Thu, Jul 22, 2010 at 01:09:33PM +0200, Dan Carpenter wrote:
> This is a smatch thing.
>
> net/mac80211/rc80211_minstrel_ht.c +639 minstrel_ht_update_caps(15)
> warn: variable dereferenced before check 'sta'
> 631 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
> 632 struct ieee80211_local *local = hw_to_local(mp->hw);
> 633 u16 sta_cap = sta->ht_cap.cap;
> ^^^^^^^^^^^^^^^
> Dereferenced here.
>
> 634 int ack_dur;
> 635 int stbc;
> 636 int i;
> 637
> 638 /* fall back to the old minstrel for legacy stations */
> 639 if (sta && !sta->ht_cap.ht_supported) {
> ^^^
> Checked here.
>
> 640 msp->is_ht = false;
> 641 memset(&msp->legacy, 0, sizeof(msp->legacy));
>
> It seems like a bug, but I'm not sure how to deal with it.
I think that sta NULL check is unnecessary there.
John
--
John W. Linville Someday the world will need a hero, and you
linville@tuxdriver.com might be all we have. Be ready.
next prev parent reply other threads:[~2010-07-22 19:45 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-22 11:09 potential null deref in minstrel_ht_update_caps()? Dan Carpenter
2010-07-22 19:35 ` John W. Linville [this message]
2010-07-22 19:39 ` [PATCH] minstrel_ht: remove unnecessary NULL check in minstrel_ht_update_caps John W. Linville
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