* double unlock in rng_dev_read()
@ 2009-12-23 13:15 Dan Carpenter
2009-12-23 14:36 ` Herbert Xu
0 siblings, 1 reply; 5+ messages in thread
From: Dan Carpenter @ 2009-12-23 13:15 UTC (permalink / raw)
To: Matt Mackall; +Cc: Herbert Xu, linux-kernel
It seems like we unlock rng_mutex twice (2.6.33-rc1).
drivers/char/hw_random/core.c
151 mutex_unlock(&rng_mutex);
152
153 if (need_resched())
154 schedule_timeout_interruptible(1);
155
156 if (signal_pending(current)) {
157 err = -ERESTARTSYS;
158 goto out;
159 }
160 }
161 out_unlock:
162 mutex_unlock(&rng_mutex);
regards,
dan carpenter
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: double unlock in rng_dev_read()
2009-12-23 13:15 double unlock in rng_dev_read() Dan Carpenter
@ 2009-12-23 14:36 ` Herbert Xu
2009-12-23 14:53 ` Dan Carpenter
0 siblings, 1 reply; 5+ messages in thread
From: Herbert Xu @ 2009-12-23 14:36 UTC (permalink / raw)
To: Dan Carpenter, Matt Mackall, linux-kernel
On Wed, Dec 23, 2009 at 03:15:52PM +0200, Dan Carpenter wrote:
> It seems like we unlock rng_mutex twice (2.6.33-rc1).
>
> drivers/char/hw_random/core.c
> 151 mutex_unlock(&rng_mutex);
> 152
> 153 if (need_resched())
> 154 schedule_timeout_interruptible(1);
> 155
> 156 if (signal_pending(current)) {
> 157 err = -ERESTARTSYS;
> 158 goto out;
> 159 }
> 160 }
> 161 out_unlock:
> 162 mutex_unlock(&rng_mutex);
Hmm, are you sure you didn't mistake out for out_unlock? :)
--
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: double unlock in rng_dev_read()
2009-12-23 14:36 ` Herbert Xu
@ 2009-12-23 14:53 ` Dan Carpenter
2009-12-23 15:23 ` Herbert Xu
0 siblings, 1 reply; 5+ messages in thread
From: Dan Carpenter @ 2009-12-23 14:53 UTC (permalink / raw)
To: Herbert Xu; +Cc: Matt Mackall, linux-kernel
On Wed, Dec 23, 2009 at 10:36:58PM +0800, Herbert Xu wrote:
> On Wed, Dec 23, 2009 at 03:15:52PM +0200, Dan Carpenter wrote:
> > It seems like we unlock rng_mutex twice (2.6.33-rc1).
> >
> > drivers/char/hw_random/core.c
> > 151 mutex_unlock(&rng_mutex);
> > 152
> > 153 if (need_resched())
> > 154 schedule_timeout_interruptible(1);
> > 155
> > 156 if (signal_pending(current)) {
> > 157 err = -ERESTARTSYS;
> > 158 goto out;
> > 159 }
> > 160 }
> > 161 out_unlock:
> > 162 mutex_unlock(&rng_mutex);
>
> Hmm, are you sure you didn't mistake out for out_unlock? :)
No no. I mean when size hits zero we are rng_mutex is unlocked.
regards,
dan carpenter
> --
> Visit Openswan at http://www.openswan.org/
> Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
> Home Page: http://gondor.apana.org.au/~herbert/
> PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: double unlock in rng_dev_read()
2009-12-23 14:53 ` Dan Carpenter
@ 2009-12-23 15:23 ` Herbert Xu
2009-12-24 10:51 ` Dan Carpenter
0 siblings, 1 reply; 5+ messages in thread
From: Herbert Xu @ 2009-12-23 15:23 UTC (permalink / raw)
To: Dan Carpenter, Matt Mackall, linux-kernel
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!
commit f5908267b67917b8cbd98b27fd2be9b5f62ec76f
Author: Herbert Xu <herbert@gondor.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@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.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@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: double unlock in rng_dev_read()
2009-12-23 15:23 ` Herbert Xu
@ 2009-12-24 10:51 ` Dan Carpenter
0 siblings, 0 replies; 5+ messages in thread
From: Dan Carpenter @ 2009-12-24 10:51 UTC (permalink / raw)
To: Herbert Xu; +Cc: Matt Mackall, linux-kernel
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@gmail.com>
regards,
dan carpenter
> commit f5908267b67917b8cbd98b27fd2be9b5f62ec76f
> Author: Herbert Xu <herbert@gondor.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@gmail.com>
> Signed-off-by: Herbert Xu <herbert@gondor.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@gondor.apana.org.au>
> Home Page: http://gondor.apana.org.au/~herbert/
> PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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2009-12-23 13:15 double unlock in rng_dev_read() Dan Carpenter
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2009-12-24 10:51 ` Dan Carpenter
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