netdev - Re: [Linux-kernel-mentees] [PATCH net] rds: Prevent kernel-infoleak in rds_notify_queue

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]

Message-ID: <20200801053833.GK75549@unreal>
Date:   Sat, 1 Aug 2020 08:38:33 +0300
From:   Leon Romanovsky <leon@...nel.org>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     Jason Gunthorpe <jgg@...pe.ca>, Peilin Ye <yepeilin.cs@...il.com>,
        Santosh Shilimkar <santosh.shilimkar@...cle.com>,
        "David S. Miller" <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>,
        Dan Carpenter <dan.carpenter@...cle.com>,
        Arnd Bergmann <arnd@...db.de>,
        linux-kernel-mentees@...ts.linuxfoundation.org,
        netdev@...r.kernel.org, linux-rdma@...r.kernel.org,
        rds-devel@....oracle.com, linux-kernel@...r.kernel.org
Subject: Re: [Linux-kernel-mentees] [PATCH net] rds: Prevent kernel-infoleak
 in rds_notify_queue_get()

On Fri, Jul 31, 2020 at 07:19:24PM +0200, Greg Kroah-Hartman wrote:
> On Fri, Jul 31, 2020 at 11:36:04AM -0300, Jason Gunthorpe wrote:
> > On Fri, Jul 31, 2020 at 04:21:48PM +0200, Greg Kroah-Hartman wrote:
> >
> > > > The spec was updated in C11 to require zero'ing padding when doing
> > > > partial initialization of aggregates (eg = {})
> > > >
> > > > """if it is an aggregate, every member is initialized (recursively)
> > > > according to these rules, and any padding is initialized to zero
> > > > bits;"""
> > >
> > > But then why does the compilers not do this?
> >
> > Do you have an example?
>
> At the moment, no, but we have had them in the past due to security
> issues we have had to fix for this.

Is it still relevant after bump of required GCC version to build kernel?

I afraid that without solid example such changes will start to be
treated with cargo cult.

Jason,

I'm using {} instead of {0} because of this GCC bug.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53119

Thanks