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From: Inaky Perez-Gonzalez <inaky@linux.intel.com>
To: David Miller <davem@davemloft.net>
Cc: cindy.h.kao@intel.com, wimax@linuxwimax.org,
	netdev@vger.kernel.org, kernel-janitors@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-wimax@intel.com,
	darrenrjenkins@gmail.com
Subject: Re: [PATCH] drivers/net/wimax/i2400m/fw.c fix possible double free
Date: Tue, 16 Mar 2010 23:05:47 -0700	[thread overview]
Message-ID: <1268805947.2310.1.camel@localhost.localdomain> (raw)
In-Reply-To: <20100316.141445.27416807.davem@davemloft.net>

On Tue, 2010-03-16 at 14:14 -0700, David Miller wrote: 
> From: Darren Jenkins <darrenrjenkins@gmail.com>
> Date: Tue, 16 Mar 2010 22:46:28 +1100
> 
> > i2400m_fw_check() can free i2400m->fw_hdrs if krealloc() fails causing a double free
> > Add a check so we don't free the memory a second time.
> > 
> > coverity CID: 13455
> > 
> > Signed-off-by: Darren Jenkins <darrenrjenkins@gmail.com>
> 
> Please don't fix it like this, the check is obscure and it's
> allowing other bugs to happen.
> 
> If krealloc() fails, any refrence to i2400m->fw_hdrs is
> referencing freed memory.
> 
> Therefore the krealloc() failure handling in this driver should NULL
> out i2400m->fw_hdrs and that will fix the double kfree problem as well
> as trap any stray references.

I agree with David, the fix is quite obscure. The error path in
i2400m_fw_check()'s call to i2400m_kzrealloc_2x() should be rather
cleaning up in a better way.

  reply	other threads:[~2010-03-17  6:05 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-03-16 11:46 [PATCH] drivers/net/wimax/i2400m/fw.c fix possible double free Darren Jenkins
2010-03-16 21:14 ` David Miller
2010-03-17  6:05   ` Inaky Perez-Gonzalez [this message]
  -- strict thread matches above, loose matches on Subject: below --
2010-03-17 12:40 Darren Jenkins
2010-03-17 22:10 ` Inaky Perez-Gonzalez
2010-03-18  8:46 Darren Jenkins
2010-03-20 21:24 ` David Miller

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