Subject: Re: [PATCH net v2 1/1] net: ppp: don't call sk_chk_filter twice

From: Christoph Schulz <[email-masked]>
Date: Fri, 18 Jul 2014 23:34:50 +0200

Hello!

Am 15.07.2014 01:15, schrieb David Miller:
> From: Christoph Schulz <[email-masked]>
> Date: Mon, 14 Jul 2014 08:01:10 +0200
> 
>> From: Christoph Schulz <[email-masked]>
>>
>> Commit 568f194e8bd16c353ad50f9ab95d98b20578a39d ("net: ppp: use
>> sk_unattached_filter api") causes sk_chk_filter() to be called twice when
>> setting a PPP pass or active filter. This applies to both the generic PPP
>> subsystem implemented by drivers/net/ppp/ppp_generic.c and the ISDN PPP
>> subsystem implemented by drivers/isdn/i4l/isdn_ppp.c. The first call is from
>> within get_filter().
>> [...]
>> For 3.15.x, this proposed change is a bugfix rather than a pure optimization as
>> in that branch, sk_chk_filter() may replace filter codes by other codes which
>> are not recognized when executing sk_chk_filter() a second time. So with
>> 3.15.x, if sk_chk_filter() is called twice, the second invocation may yield
>> EINVAL (this depends on the filter codes found in the filter to be set, but
>> because the replacement is done for frequently used codes, this is almost
>> always the case). The net effect is that setting pass and/or active PPP filters
>> does not work anymore, since sk_unattached_filter_create() always returns
>> EINVAL due to the second call to sk_chk_filter(), regardless whether the filter
>> was originally sane or not.
>>
>> Signed-off-by: Christoph Schulz <[email-masked]>
> 
> Applied, thank you.

As the commit message says, this patch is a bugfix for the 3.15.y
branch. However, I don't see it in the netdev stable-queue. Could you
please add it to -stable for 3.15.y?

Thank you in advance,

Christoph Schulz