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 PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Fri, 19 Jan 2007 16:23:19 +0300 From: Michael Tokarev <mjt@....msk.ru> To: Patrick McHardy <kaber@...sh.net> CC: Jarek Poplawski <jarkao2@...pl>, netdev@...r.kernel.org, Herbert Xu <herbert@...dor.apana.org.au> Subject: Re: [PATCH] tcp_output: Re: rare bad TCP checksum with 2.6.19? Patrick McHardy wrote: > Jarek Poplawski wrote: >> Here is my patch proposal. If I'm not totally wrong, >> there is a possibility that, during collapsing, empty >> skb with FIN is added to "normal" packet and changes >> its ip_summed field to CHECKSUM_NONE. >> >> diff -Nurp linux-2.6.19-/net/ipv4/tcp_output.c linux-2.6.19/net/ipv4/tcp_output.c >> --- linux-2.6.19-/net/ipv4/tcp_output.c 2006-11-29 22:57:37.000000000 +0100 >> +++ linux-2.6.19/net/ipv4/tcp_output.c 2007-01-19 07:58:39.000000000 +0100 >> @@ -1590,7 +1590,8 @@ static void tcp_retrans_try_collapse(str >> >> memcpy(skb_put(skb, next_skb_size), next_skb->data, next_skb_size); >> >> - skb->ip_summed = next_skb->ip_summed; >> + if (next_skb->ip_summed == CHECKSUM_PARTIAL) >> + skb->ip_summed = CHECKSUM_PARTIAL; >> >> if (skb->ip_summed != CHECKSUM_PARTIAL) >> skb->csum = csum_block_add(skb->csum, next_skb->csum, skb_size); >> > > I noticed this too, but I can't see how it could lead to > a partial checksum on the wire since the checksumming is > done after changing ip_summed to CHECKSUM_NONE. Is this > patch verified to fix Michael's problem? It seems to fix this "my" problem, yes - at least I can't reproduce it anymore. Tcpdump is running however - let's see... :) /mjt - 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
Powered by blists - more mailing lists