Re: Asterisk deadlocks since Kernel 4.1

Re: Asterisk deadlocks since Kernel 4.1

[Herbert Xu]

On Sun, Dec 06, 2015 at 09:56:34PM +0100, Stefan Priebe wrote:
> Hi Herbert,
> 
> i think i found the issue in 4.1 with netlink. Somebody made a
> mistake while backporting or cherry-picking your patch "netlink: Fix
> autobind race condition that leads to zero port ID" to 4.1.
> 
> It misses a goto in 4.1.
> 
> This goto is missing in 4.1:
> 
> diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
> index 4017e12..f15c001 100644
> --- a/net/netlink/af_netlink.c
> +++ b/net/netlink/af_netlink.c
> @@ -1132,7 +1132,6 @@ static int netlink_insert(struct sock *sk, u32 portid)
>                 if (err == -EEXIST)
>                         err = -EADDRINUSE;
>                 sock_put(sk);
> -               goto err;
>         }
> 
>         /* We need to ensure that the socket is hashed and visible. */
> 
> Can you please confirm, that this is not correct and might cause
> those issues.

Well spotted! Yes this would be a fatal error and can cause the
problems you guys are seeing.

Thanks,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: Asterisk deadlocks since Kernel 4.1

[Stefan Priebe - Profihost AG]

Hi Herbert,

Am 07.12.2015 um 02:20 schrieb Herbert Xu:
> On Sun, Dec 06, 2015 at 09:56:34PM +0100, Stefan Priebe wrote:
>> Hi Herbert,
>>
>> i think i found the issue in 4.1 with netlink. Somebody made a
>> mistake while backporting or cherry-picking your patch "netlink: Fix
>> autobind race condition that leads to zero port ID" to 4.1.
>>
>> It misses a goto in 4.1.
>>
>> This goto is missing in 4.1:
>>
>> diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
>> index 4017e12..f15c001 100644
>> --- a/net/netlink/af_netlink.c
>> +++ b/net/netlink/af_netlink.c
>> @@ -1132,7 +1132,6 @@ static int netlink_insert(struct sock *sk, u32 portid)
>>                 if (err == -EEXIST)
>>                         err = -EADDRINUSE;
>>                 sock_put(sk);
>> -               goto err;
>>         }
>>
>>         /* We need to ensure that the socket is hashed and visible. */
>>
>> Can you please confirm, that this is not correct and might cause
>> those issues.
> 
> Well spotted! Yes this would be a fatal error and can cause the
> problems you guys are seeing.

Thanks, good. Can you help me to get this fix upstream into the stable
lines?

Stefan

> 
> Thanks,
> 

netlink: Add missing goto statement to netlink_insert

[Herbert Xu]

On Mon, Dec 07, 2015 at 07:58:25AM +0100, Stefan Priebe - Profihost AG wrote:
>
> Thanks, good. Can you help me to get this fix upstream into the stable
> lines?

Sure.  Greg, please apply this patch to fix up the backport for 4.1.

---8<---
The backport of 1f770c0a09da855a2b51af6d19de97fb955eca85 ("netlink:
Fix autobind race condition that leads to zero port ID") missed a
goto statement, which causes netlink to break subtly.

This was discovered by Stefan Priebe <s.priebe@profihost.ag>.

Fixes: 4e2776241766 ("netlink: Fix autobind race condition that...")
Reported-by: Stefan Priebe <s.priebe@profihost.ag>
Reported-by: Philipp Hahn <pmhahn@pmhahn.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index d139c43..0d6038c 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1118,6 +1118,7 @@ static int netlink_insert(struct sock *sk, u32 portid)
 		if (err == -EEXIST)
 			err = -EADDRINUSE;
 		sock_put(sk);
+		goto err;
 	}
 
 	/* We need to ensure that the socket is hashed and visible. */

-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: netlink: Add missing goto statement to netlink_insert

[David Miller]

From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Tue, 8 Dec 2015 14:13:19 +0800

> On Mon, Dec 07, 2015 at 07:58:25AM +0100, Stefan Priebe - Profihost AG wrote:
>>
>> Thanks, good. Can you help me to get this fix upstream into the stable
>> lines?
> 
> Sure.  Greg, please apply this patch to fix up the backport for 4.1.

Herbert, thanks so much for taking care of this.

> ---8<---
> The backport of 1f770c0a09da855a2b51af6d19de97fb955eca85 ("netlink:
> Fix autobind race condition that leads to zero port ID") missed a
> goto statement, which causes netlink to break subtly.
> 
> This was discovered by Stefan Priebe <s.priebe@profihost.ag>.
> 
> Fixes: 4e2776241766 ("netlink: Fix autobind race condition that...")
> Reported-by: Stefan Priebe <s.priebe@profihost.ag>
> Reported-by: Philipp Hahn <pmhahn@pmhahn.de>
> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Acked-by: David S. Miller <davem@davemloft.net>

> 
> diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
> index d139c43..0d6038c 100644
> --- a/net/netlink/af_netlink.c
> +++ b/net/netlink/af_netlink.c
> @@ -1118,6 +1118,7 @@ static int netlink_insert(struct sock *sk, u32 portid)
>  		if (err == -EEXIST)
>  			err = -EADDRINUSE;
>  		sock_put(sk);
> +		goto err;
>  	}
>  
>  	/* We need to ensure that the socket is hashed and visible. */
> 
> -- 
> Email: Herbert Xu <herbert@gondor.apana.org.au>
> Home Page: http://gondor.apana.org.au/~herbert/
> PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: netlink: Add missing goto statement to netlink_insert

[Greg KH]

On Tue, Dec 08, 2015 at 02:13:19PM +0800, Herbert Xu wrote:
> On Mon, Dec 07, 2015 at 07:58:25AM +0100, Stefan Priebe - Profihost AG wrote:
> >
> > Thanks, good. Can you help me to get this fix upstream into the stable
> > lines?
> 
> Sure.  Greg, please apply this patch to fix up the backport for 4.1.

Now queued up, thanks for the fix.

greg k-h

Patch "netlink: Add missing goto statement to netlink_insert" has been added to the 4.1-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    netlink: Add missing goto statement to netlink_insert

to the 4.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     netlink-add-missing-goto-statement-to-netlink_insert.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From herbert@gondor.apana.org.au  Tue Dec  8 22:28:59 2015
From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Tue, 8 Dec 2015 14:13:19 +0800
Subject: netlink: Add missing goto statement to netlink_insert
To: Stefan Priebe - Profihost AG <s.priebe@profihost.ag>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>, Florian Weimer <fweimer@redhat.com>, Thomas Gleixner <tglx@linutronix.de>, netdev@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, jannik Winkel <j.winkel@profihost.ag>, Marco Schinkel <m.schinkel@profihost.ag>, "David S. Miller" <davem@davemloft.net>, stable@vger.kernel.org
Message-ID: <20151208061319.GA16209@gondor.apana.org.au>
Content-Disposition: inline

From: Herbert Xu <herbert@gondor.apana.org.au>

The backport of 1f770c0a09da855a2b51af6d19de97fb955eca85 ("netlink:
Fix autobind race condition that leads to zero port ID") missed a
goto statement, which causes netlink to break subtly.

This was discovered by Stefan Priebe <s.priebe@profihost.ag>.

Fixes: 4e2776241766 ("netlink: Fix autobind race condition that...")
Reported-by: Stefan Priebe <s.priebe@profihost.ag>
Reported-by: Philipp Hahn <pmhahn@pmhahn.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 net/netlink/af_netlink.c |    1 +
 1 file changed, 1 insertion(+)

--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1118,6 +1118,7 @@ static int netlink_insert(struct sock *s
 		if (err == -EEXIST)
 			err = -EADDRINUSE;
 		sock_put(sk);
+		goto err;
 	}
 
 	/* We need to ensure that the socket is hashed and visible. */


Patches currently in stable-queue which might be from herbert@gondor.apana.org.au are

queue-4.1/netlink-add-missing-goto-statement-to-netlink_insert.patch