netdev - Re: [PATCH 27/33] sctp: export sctp_setsockopt

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: <129070.1589556002@warthog.procyon.org.uk>
Date:   Fri, 15 May 2020 16:20:02 +0100
From:   David Howells <dhowells@...hat.com>
To:     Christoph Hellwig <hch@....de>
Cc:     dhowells@...hat.com,
        Marcelo Ricardo Leitner <marcelo.leitner@...il.com>,
        Eric Dumazet <edumazet@...gle.com>,
        linux-nvme@...ts.infradead.org, linux-sctp@...r.kernel.org,
        target-devel@...r.kernel.org, linux-afs@...ts.infradead.org,
        drbd-dev@...ts.linbit.com, linux-cifs@...r.kernel.org,
        rds-devel@....oracle.com, linux-rdma@...r.kernel.org,
        cluster-devel@...hat.com, Alexey Kuznetsov <kuznet@....inr.ac.ru>,
        linux-block@...r.kernel.org, Jakub Kicinski <kuba@...nel.org>,
        ceph-devel@...r.kernel.org, linux-nfs@...r.kernel.org,
        Neil Horman <nhorman@...driver.com>,
        Hideaki YOSHIFUJI <yoshfuji@...ux-ipv6.org>,
        netdev@...r.kernel.org, Vlad Yasevich <vyasevich@...il.com>,
        linux-kernel@...r.kernel.org, Jon Maloy <jmaloy@...hat.com>,
        Ying Xue <ying.xue@...driver.com>,
        "David S. Miller" <davem@...emloft.net>, ocfs2-devel@....oracle.com
Subject: Re: [PATCH 27/33] sctp: export sctp_setsockopt_bindx

Christoph Hellwig <hch@....de> wrote:

> > The advantage on using kernel_setsockopt here is that sctp module will
> > only be loaded if dlm actually creates a SCTP socket.  With this
> > change, sctp will be loaded on setups that may not be actually using
> > it. It's a quite big module and might expose the system.
> 
> True.  Not that the intent is to kill kernel space callers of setsockopt,
> as I plan to remove the set_fs address space override used for it.

For getsockopt, does it make sense to have the core kernel load optval/optlen
into a buffer before calling the protocol driver?  Then the driver need not
see the userspace pointer at all.

Similar could be done for setsockopt - allocate a buffer of the size requested
by the user inside the kernel and pass it into the driver, then copy the data
back afterwards.

David