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: Wed, 30 Apr 2014 10:53:42 -0400 From: Neal Cardwell <ncardwell@...gle.com> To: Eric Dumazet <eric.dumazet@...il.com> Cc: Liu Yu <allanliuyu@...il.com>, Stephen Hemminger <shemminger@...tta.com>, "David S. Miller" <davem@...emloft.net>, Netdev <netdev@...r.kernel.org> Subject: Re: [PATCH] tcp_cubic: fix the range of delayed_ack On Wed, Apr 30, 2014 at 10:18 AM, Eric Dumazet <eric.dumazet@...il.com> wrote: > On Wed, 2014-04-30 at 17:34 +0800, Liu Yu wrote: >> From: Liu Yu <allanyuliu@...cent.com> >> >> commit b9f47a3aaeab (tcp_cubic: limit delayed_ack ratio to prevent >> divide error) try to prevent divide error, but there is still a little >> chance that delayed_ack can reach zero. In case the param cnt get >> negative value, then ratio+cnt would overflow and may happen to be zero. >> As a result, min(ratio, ACK_RATIO_LIMIT) will calculate to be zero. >> >> In some old kernels, such as 2.6.32, there is a bug that would >> pass negative param, which then ultimately leads to this divide error. >> >> commit 5b35e1e6e9c (tcp: fix tcp_trim_head() to adjust segment count >> with skb MSS) fixed the negative param issue. However, >> it's safe that we fix the range of delayed_ack as well, >> to make sure we do not hit a divide by zero. >> >> CC: Stephen Hemminger <shemminger@...tta.com> >> Signed-off-by: Liu Yu <allanyuliu@...cent.com> >> --- >> net/ipv4/tcp_cubic.c | 2 +- >> 1 files changed, 1 insertions(+), 1 deletions(-) > > Signed-off-by: Eric Dumazet <edumazet@...gle.com> Acked-by: Neal Cardwell <ncardwell@...gle.com> Indeed, thanks! neal -- 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