netdev - Re: [PATCH net v3 2/3] Treewide: Stop corrupting socket's task

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: <20221215135905.GA19378@pc-4.home>
Date:   Thu, 15 Dec 2022 14:59:05 +0100
From:   Guillaume Nault <gnault@...hat.com>
To:     David Howells <dhowells@...hat.com>
Cc:     Benjamin Coddington <bcodding@...hat.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>,
        "David S. Miller" <davem@...emloft.net>,
        Eric Dumazet <edumazet@...gle.com>,
        Philipp Reisner <philipp.reisner@...bit.com>,
        Lars Ellenberg <lars.ellenberg@...bit.com>,
        Christoph Böhmwalder 
        <christoph.boehmwalder@...bit.com>, Jens Axboe <axboe@...nel.dk>,
        Josef Bacik <josef@...icpanda.com>,
        Keith Busch <kbusch@...nel.org>,
        Christoph Hellwig <hch@....de>,
        Sagi Grimberg <sagi@...mberg.me>,
        Lee Duncan <lduncan@...e.com>, Chris Leech <cleech@...hat.com>,
        Mike Christie <michael.christie@...cle.com>,
        "James E.J. Bottomley" <jejb@...ux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@...cle.com>,
        Valentina Manea <valentina.manea.m@...il.com>,
        Shuah Khan <shuah@...nel.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Marc Dionne <marc.dionne@...istor.com>,
        Steve French <sfrench@...ba.org>,
        Christine Caulfield <ccaulfie@...hat.com>,
        David Teigland <teigland@...hat.com>,
        Mark Fasheh <mark@...heh.com>,
        Joel Becker <jlbec@...lplan.org>,
        Joseph Qi <joseph.qi@...ux.alibaba.com>,
        Eric Van Hensbergen <ericvh@...il.com>,
        Latchesar Ionkov <lucho@...kov.net>,
        Dominique Martinet <asmadeus@...ewreck.org>,
        Ilya Dryomov <idryomov@...il.com>,
        Xiubo Li <xiubli@...hat.com>,
        Chuck Lever <chuck.lever@...cle.com>,
        Jeff Layton <jlayton@...nel.org>,
        Trond Myklebust <trond.myklebust@...merspace.com>,
        Anna Schumaker <anna@...nel.org>,
        Steffen Klassert <steffen.klassert@...unet.com>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        netdev@...r.kernel.org
Subject: Re: [PATCH net v3 2/3] Treewide: Stop corrupting socket's task_frag

On Thu, Dec 15, 2022 at 12:12:42PM +0000, David Howells wrote:
> 
> Benjamin Coddington <bcodding@...hat.com> wrote:
> 
> > diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
> > index eccc3cd0cb70..ac75ad18db83 100644
> > --- a/fs/afs/rxrpc.c
> > +++ b/fs/afs/rxrpc.c
> > @@ -46,6 +46,7 @@ int afs_open_socket(struct afs_net *net)
> >  		goto error_1;
> >  
> >  	socket->sk->sk_allocation = GFP_NOFS;
> > +	socket->sk->sk_use_task_frag = false;
> >  
> >  	/* bind the callback manager's address to make this a server socket */
> >  	memset(&srx, 0, sizeof(srx));
> 
> Possibly this should be done in net/rxrpc/local_object.c too?  Or maybe in
> udp_sock_create() or sock_create_kern()?

UDP tunnels typically don't need to set sk_use_task_frag, as they don't
call sk_page_frag(). One exception would be if they called
ip_append_data() (or ip6_append_data()), but none of them seem to do
that (and I can't see any reason why they would).

And net/rxrpc/local_object.c doesn't seems very different in this regard.

Maybe setting sk_use_task_frag in fs/afs/rxrpc.c was overzealous but
I'm not familiar enough with the AF_RXRPC family to tell. If AF_RXRPC
sockets can't call sk_page_frag() and have no reason to do so in the
future, then it should be safe to drop this chunk.

> David
>