From: Dan Carpenter <dan.carpenter@oracle.com>
To: valdis.kletnieks@vt.edu
Cc: gregkh@linuxfoundation.org, John Whitmore <arigead@gmail.com>,
Kees Cook <keescook@chromium.org>,
devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org,
kernelnewbies@kernelnewbies.org
Subject: Re: [PATCH] fix error handling in drivers/staging/rtl8192u/ieee80211/ieee80211_module.c
Date: Thu, 27 Sep 2018 17:24:03 +0300 [thread overview]
Message-ID: <20180927142403.z27x6wvq54ealwwt@mwanda> (raw)
In-Reply-To: <13450.1537984337@turing-police.cc.vt.edu>
On Wed, Sep 26, 2018 at 01:52:17PM -0400, valdis.kletnieks@vt.edu wrote:
> John notes that if the kzalloc of ieee->pHTInfo fails, we fail to call
> ieee80211_networks_free(). In addition, that function has an un-needed check
> before kfree().
>
> Reported-by: John Whitmore <arigead@gmail.com>
> Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
> ---
> diff --git a/drivers/staging/rtl8192u/ieee80211/ieee80211_module.c b/drivers/staging/rtl8192u/ieee80211/ieee80211_module.c
> index 90a097f2cd4e..97ff0371b5bb 100644
> --- a/drivers/staging/rtl8192u/ieee80211/ieee80211_module.c
> +++ b/drivers/staging/rtl8192u/ieee80211/ieee80211_module.c
> @@ -78,8 +78,6 @@ static inline int ieee80211_networks_allocate(struct ieee80211_device *ieee)
>
> static inline void ieee80211_networks_free(struct ieee80211_device *ieee)
> {
> - if (!ieee->networks)
> - return;
> kfree(ieee->networks);
> ieee->networks = NULL;
> }
> @@ -180,6 +178,7 @@ struct net_device *alloc_ieee80211(int sizeof_priv)
> return dev;
>
> failed:
> + ieee80211_networks_free(ieee);
> if (dev)
> free_netdev(dev);
When there is a "goto failed;" then it's called "one err style" error
handling and we're just asking for bugs... In this case the bug is that
we're not allowd to call ieee80211_networks_free() with a NULL
"ieee" parameter. The right thing to do is to only call
ieee80211_networks_free() if we know that ieee80211_networks_allocate()
succeeded.
regards,
dan carpenter
next prev parent reply other threads:[~2018-09-27 14:24 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-26 17:52 [PATCH] fix error handling in drivers/staging/rtl8192u/ieee80211/ieee80211_module.c valdis.kletnieks
2018-09-26 18:04 ` Kees Cook
2018-09-27 14:24 ` Dan Carpenter [this message]
2018-09-27 15:43 ` Kees Cook
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