From: Jakub Kicinski <kuba@kernel.org>
To: "Paraschiv, Andra-Irina" <andraprs@amazon.com>
Cc: Stefano Garzarella <sgarzare@redhat.com>,
netdev <netdev@vger.kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
"David S . Miller" <davem@davemloft.net>,
David Duncan <davdunc@amazon.com>,
Dexuan Cui <decui@microsoft.com>, Alexander Graf <graf@amazon.de>,
Jorgen Hansen <jhansen@vmware.com>,
Stefan Hajnoczi <stefanha@redhat.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>
Subject: Re: [PATCH net-next v2 1/4] vm_sockets: Include flags field in the vsock address data structure
Date: Wed, 9 Dec 2020 09:30:19 -0800 [thread overview]
Message-ID: <20201209093019.1caae20e@kicinski-fedora-pc1c0hjn.DHCP.thefacebook.com> (raw)
In-Reply-To: <4f2a1ac5-68c7-190f-6abf-452f67b3a7f4@amazon.com>
On Wed, 9 Dec 2020 17:17:56 +0200 Paraschiv, Andra-Irina wrote:
> > I agree that could be a problem, but here some considerations:
> > - I checked some applications (qemu-guest-agent, ncat, iperf-vsock) and
> > all use the same pattern: allocate memory, initialize all the
> > sockaddr_vm to zero (to be sure to initialize the svm_zero), set the
> > cid and port fields.
> > So we should be safe, but of course it may not always be true.
> >
> > - For now the issue could affect only nested VMs. We introduced this
> > support one year ago, so it's something new and maybe we don't cause
> > too many problems.
> >
> > As an alternative, what about using 1 or 2 bytes from svm_zero[]?
> > These must be set at zero, even if we only check the first byte in the
> > kernel.
>
> Thanks for the follow-up info.
>
> We can also consider the "svm_zero" option and could use 2 bytes from
> that field for "svm_flags", keeping the same "unsigned short" type.
Or use svm_zero as a gate for interpreting other fields?
If svm_zero[0]* == something start checking the value of reserved1?
* in practice the name can be unioned to something more palatable ;)
next prev parent reply other threads:[~2020-12-09 17:31 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-04 17:02 [PATCH net-next v2 0/4] vsock: Add flags field in the vsock address Andra Paraschiv
2020-12-04 17:02 ` [PATCH net-next v2 1/4] vm_sockets: Include flags field in the vsock address data structure Andra Paraschiv
2020-12-07 9:59 ` Stefano Garzarella
2020-12-07 19:25 ` Paraschiv, Andra-Irina
2020-12-07 21:29 ` Jakub Kicinski
2020-12-08 18:23 ` Paraschiv, Andra-Irina
2020-12-08 18:42 ` Jakub Kicinski
2020-12-09 10:48 ` Stefano Garzarella
2020-12-09 15:17 ` Paraschiv, Andra-Irina
2020-12-09 17:30 ` Jakub Kicinski [this message]
2020-12-10 15:29 ` Paraschiv, Andra-Irina
2020-12-04 17:02 ` [PATCH net-next v2 2/4] vm_sockets: Add VMADDR_FLAG_TO_HOST vsock flag Andra Paraschiv
2020-12-07 9:59 ` Stefano Garzarella
2020-12-07 19:45 ` Paraschiv, Andra-Irina
2020-12-04 17:02 ` [PATCH net-next v2 3/4] af_vsock: Set VMADDR_FLAG_TO_HOST flag on the receive path Andra Paraschiv
2020-12-07 9:59 ` Stefano Garzarella
2020-12-04 17:02 ` [PATCH net-next v2 4/4] af_vsock: Assign the vsock transport considering the vsock address flags Andra Paraschiv
2020-12-07 10:00 ` Stefano Garzarella
2020-12-07 19:51 ` Paraschiv, Andra-Irina
2020-12-07 10:05 ` [PATCH net-next v2 0/4] vsock: Add flags field in the vsock address Stefano Garzarella
2020-12-07 19:18 ` Paraschiv, Andra-Irina
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