netdev - Re: [PATCH net] ping: fix the dif and sdif check in ping

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: <20220223075251.7d512101@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>
Date:   Wed, 23 Feb 2022 07:52:51 -0800
From:   Jakub Kicinski <kuba@...nel.org>
To:     Xin Long <lucien.xin@...il.com>
Cc:     network dev <netdev@...r.kernel.org>, davem <davem@...emloft.net>,
        Vasiliy Kulikov <segoon@...nwall.com>
Subject: Re: [PATCH net] ping: fix the dif and sdif check in ping_lookup

On Wed, 23 Feb 2022 14:08:06 +0800 Xin Long wrote:
> On Thu, Feb 17, 2022 at 11:57 PM Jakub Kicinski <kuba@...nel.org> wrote:
> > Are you sure this is not reachable from some networking path allowing
> > attacker (or local user) to DoS the kernel logs?  
> Hi, Jakub, sorry for late.
> 
> I actually didn't see how a skb with protocol != IP/IPV6 could reach here.
> ping_err() is using "BUG()" for this kind of case.
> I added this 'else' branch mostly to avoid the possible compiling
> warning for "Use of uninitialized value dif/sdif".

Understood but it's best practice to avoid prints on the datapath.
We should either drop the print completely (given it's impossible)
or make it _once.