netdev - Re: [PATCH stable 3.10-3.16] tcp: Fix crash in TCP Fast Open

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

Date:	Wed, 15 Apr 2015 14:33:50 -0400 (EDT)
From:	David Miller <davem@...emloft.net>
To:	eric.dumazet@...il.com
Cc:	ben@...adent.org.uk, stable@...r.kernel.org,
	netdev@...r.kernel.org, 782515@...s.debian.org
Subject: Re: [PATCH stable 3.10-3.16] tcp: Fix crash in TCP Fast Open

From: Eric Dumazet <eric.dumazet@...il.com>
Date: Wed, 15 Apr 2015 11:22:44 -0700

> On Wed, 2015-04-15 at 19:00 +0100, Ben Hutchings wrote:
>> Commit 355a901e6cf1 ("tcp: make connect() mem charging friendly")
>> changed tcp_send_syn_data() to perform an open-coded copy of the 'syn'
>> skb rather than using skb_copy_expand().
>> 
>> The open-coded copy does not cover the skb_shared_info::gso_segs
>> field, so in the new skb it is left set to 0.  When this commit was
>> backported into stable branches between 3.10.y and 3.16.7-ckty
>> inclusive, it triggered the BUG() in tcp_transmit_skb().
>> 
>> Since Linux 3.18 the GSO segment count is kept in the
>> tcp_skb_cb::tcp_gso_segs field and tcp_send_syn_data() does copy the
>> tcp_skb_cb structure to the new skb, so mainline and newer stable
>> branches are not affected.
>> 
>> Set skb_shared_info::gso_segs to the correct value of 1.
>> 
>> Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
 ...
> Looks goot to me, thanks Ben !
> 
> Acked-by: Eric Dumazet <edumazet@...gle.com>

Ben, thanks for taking care of this.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html