linux-kernel - Re: double unlock in rng_dev

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Thu, 24 Dec 2009 12:51:02 +0200
From:	Dan Carpenter <error27@...il.com>
To:	Herbert Xu <herbert@...dor.apana.org.au>
Cc:	Matt Mackall <mpm@...enic.com>, linux-kernel@...r.kernel.org
Subject: Re: double unlock in rng_dev_read()

On Wed, Dec 23, 2009 at 11:23:55PM +0800, Herbert Xu wrote:
> On Wed, Dec 23, 2009 at 04:53:36PM +0200, Dan Carpenter wrote:
> >
> > No no.  I mean when size hits zero we are rng_mutex is unlocked.
> 
> Good catch! I'll add this patch to the tree.  Please take a look
> at it.  Thanks!
> 

Great.

Acked-by: Dan Carpenter <error27@...il.com>

regards,
dan carpenter


> commit f5908267b67917b8cbd98b27fd2be9b5f62ec76f
> Author: Herbert Xu <herbert@...dor.apana.org.au>
> Date:   Wed Dec 23 23:22:34 2009 +0800
> 
>     hwrng: core - Fix double unlock in rng_dev_read
>     
>     When the loop terminates with size == 0 in rng_dev_read we will
>     unlock the rng mutex twice.
>     
>     Reported-by: Dan Carpenter <error27@...il.com>
>     Signed-off-by: Herbert Xu <herbert@...dor.apana.org.au>
> 
> diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
> index e989f67..3d9c61e 100644
> --- a/drivers/char/hw_random/core.c
> +++ b/drivers/char/hw_random/core.c
> @@ -158,10 +158,11 @@ static ssize_t rng_dev_read(struct file *filp, char __user *buf,
>  			goto out;
>  		}
>  	}
> -out_unlock:
> -	mutex_unlock(&rng_mutex);
>  out:
>  	return ret ? : err;
> +out_unlock:
> +	mutex_unlock(&rng_mutex);
> +	goto out;
>  }
>  
> -- 
> Visit Openswan at http://www.openswan.org/
> Email: Herbert Xu ~{PmV>HI~} <herbert@...dor.apana.org.au>
> Home Page: http://gondor.apana.org.au/~herbert/
> PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/