Re: [libvirt] [PATCH] virt-aa-helper: disallow VNC socket read permissions

On Fri, 2016-04-08 at 18:55 +0200, Guido Günther wrote: > On Fri, Apr 08, 2016 at 09:01:33AM -0400, Cole Robinson wrote: >> From: Simon Arlott <bugzilla.redhat.simon(a)arlott.org&gt; >> >> The VM does not need read permission for its own VNC socket to >> create(), >> bind(), accept() connections or to receive(), send(), etc. on >> connections. >> >> https://bugzilla.redhat.com/show_bug.cgi?id=1312573 >> --- >> src/security/virt-aa-helper.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/src/security/virt-aa-helper.c b/src/security/virt-aa >> -helper.c >> index 50d2a08..a4cb409 100644 >> --- a/src/security/virt-aa-helper.c >> +++ b/src/security/virt-aa-helper.c >> @@ -1062,7 +1062,7 @@ get_files(vahControl * ctl) >> for (i = 0; i < ctl->def->ngraphics; i++) { >> if (ctl->def->graphics[i]->type == >> VIR_DOMAIN_GRAPHICS_TYPE_VNC && >> ctl->def->graphics[i]->data.vnc.socket && >> - vah_add_file(&buf, ctl->def->graphics[i] >> ->data.vnc.socket, "rw")) >> + vah_add_file(&buf, ctl->def->graphics[i] >> ->data.vnc.socket, "w")) >> goto cleanup; >> } > > ACK. I'd be great if Jamie or Cedric would comment also though on > this > security sensitive stuff. I'm not a socket expert, but it sounds weird to me that recv doesn't need read access to the socket file. ACK to this patch as long a read is really not needed. Jamie, any thoughts?