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] [day] [month] [year] [list]
Message-Id: <20171220.130333.2284740049571493817.davem@davemloft.net>
Date:   Wed, 20 Dec 2017 13:03:33 -0500 (EST)
From:   David Miller <davem@...emloft.net>
To:     shli@...nel.org
Cc:     netdev@...r.kernel.org, Kernel-team@...com, shli@...com,
        kafai@...com
Subject: Re: [PATCH net V2] net: always reevalulate autoflowlabel setting
 for reset packet

From: Shaohua Li <shli@...nel.org>
Date: Tue, 19 Dec 2017 12:58:21 -0800

> From: Shaohua Li <shli@...com>
> 
> ipv6_pinfo.autoflowlabel is set in sock creation. Later if we change
> sysctl.ip6.auto_flowlabels, the ipv6_pinfo.autoflowlabel isn't changed,
> so the sock will keep the old behavior in terms of auto flowlabel. Reset
> packet is suffering from this problem, because reset packset is sent
> from a special control socket, which is created at boot time. Since
> sysctl.ipv6.auto_flowlabels is 2 by default, the control socket will
> always have its ipv6_pinfo.autoflowlabel set, even after user set
> sysctl.ipv6.auto_flowlabels to 1, so reset packset will always have
> flowlabel.
> 
> To fix this, we always reevaluate autoflowlabel setting for reset
> packet. Normal sock has the same issue too, but since the
> sysctl.ipv6.auto_flowlabels is usually set at host startup, this isn't a
> big issue for normal sock.
> 
> Cc: Martin KaFai Lau <kafai@...com>
> Signed-off-by: Shaohua Li <shli@...com>

This definitely goes into the category of hack.

Special casing resets is not the answer.

What about normal user sockets openned before the sysctl setting is
modified?

No user is going to be happy about this nice little surprise.

What you're saying is that we should specially treat the kernel
sockets that emit resets, in response to this sysctl setting being
modified.

But that is not what you are doing.  You are treating all sockets
in the system in this way, and only for reset packets.  That's
really terrible.

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ