| Message ID | 00a8955fd5a9503464f0e6122c413cf4f260cf3f.1461190765.git.crobinso@redhat.com |
|---|---|
| State | Accepted |
| Commit | 67f2b72723c242969c5282fcb9acf00cc01f2a54 |
| Headers | show |
On 04/21/2016 04:06 AM, Peter Krempa wrote: > On Wed, Apr 20, 2016 at 18:19:25 -0400, Cole Robinson wrote: >> Currently we only allow /dev/random and /dev/hwrng as host input >> for <rng><backend model='random'/> device. This was added after >> various upstream discussions in commit 4932ef45 >> >> However this restriction has generated quite a few complaints over >> the years, so a new discussion was initiated: >> >> http://www.redhat.com/archives/libvir-list/2016-April/msg00987.html >> >> Several people suggested removing the restriction, and nobody really >> spoke up to defend it. So this patch drops the path restriction >> entirely >> >> https://bugzilla.redhat.com/show_bug.cgi?id=1074464 >> --- >> docs/formatdomain.html.in | 9 ++++----- >> docs/schemas/domaincommon.rng | 3 +-- >> src/conf/domain_conf.c | 8 -------- >> tests/qemuxml2argvdata/qemuxml2argv-virtio-rng-random.args | 2 +- >> tests/qemuxml2argvdata/qemuxml2argv-virtio-rng-random.xml | 2 +- >> tests/qemuxml2xmloutdata/qemuxml2xmlout-virtio-rng-random.xml | 2 +- >> 6 files changed, 8 insertions(+), 18 deletions(-) >> >> diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in >> index 895114b..132b261 100644 >> --- a/docs/formatdomain.html.in >> +++ b/docs/formatdomain.html.in > > ... > >> @@ -6240,9 +6239,9 @@ qemu-kvm -net nic,model=? /dev/null >> <dd> >> <p> >> This backend type expects a non-blocking character device as input. >> - The only accepted paths are /dev/random and /dev/hwrng. The file >> - name is specified as contents of the <code>backend</code> element. >> - When no file name is specified the hypervisor default is used. >> + The file name is specified as contents of the >> + <code>backend</code> element. When no file name is specified the >> + this defaults to /dev/random. > > I'd rather keep the "hypervisor default" wording. /dev/urandom is in no > way platform or hypervisor agnostic. You may add though that for qemu > driver the default indeed is /dev/random. > Thanks, fixed locally. I'll wait till see if any other comments come in before deciding whether to post a V2 or not - Cole -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
On 04/26/2016 11:07 AM, Daniel P. Berrange wrote: > On Wed, Apr 20, 2016 at 06:19:25PM -0400, Cole Robinson wrote: >> Currently we only allow /dev/random and /dev/hwrng as host input >> for <rng><backend model='random'/> device. This was added after >> various upstream discussions in commit 4932ef45 >> >> However this restriction has generated quite a few complaints over >> the years, so a new discussion was initiated: >> >> http://www.redhat.com/archives/libvir-list/2016-April/msg00987.html >> >> Several people suggested removing the restriction, and nobody really >> spoke up to defend it. So this patch drops the path restriction >> entirely > > ACK, despite explicit request for details, no one has been able to > give a clear description of a security problem in using urandom. > It has all just been hand-wavey assertions with nothing to back > it up, against other people's analysis showing urandom to be safe. > Thanks, I've pushed the patch now - Cole -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list
diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index 895114b..132b261 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -6231,8 +6231,7 @@ qemu-kvm -net nic,model=? /dev/null <code>model</code> attribute. Supported source models are: </p> <ul> - <li>'random' — /dev/random (default) or /dev/hwrng - device as source (for now, no other sources are permitted)</li> + <li>'random' — a character device backend</li> <li>'egd' — a EGD protocol backend</li> </ul> </dd> @@ -6240,9 +6239,9 @@ qemu-kvm -net nic,model=? /dev/null <dd> <p> This backend type expects a non-blocking character device as input. - The only accepted paths are /dev/random and /dev/hwrng. The file - name is specified as contents of the <code>backend</code> element. - When no file name is specified the hypervisor default is used. + The file name is specified as contents of the + <code>backend</code> element. When no file name is specified the + this defaults to /dev/random. </p> </dd> <dt><code>backend model='egd'</code></dt> diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng index 3605afe..c91a3a9 100644 --- a/docs/schemas/domaincommon.rng +++ b/docs/schemas/domaincommon.rng @@ -4691,8 +4691,7 @@ <value>random</value> </attribute> <choice> - <value>/dev/random</value> - <value>/dev/hwrng</value> + <ref name='absFilePath'/> <empty/> </choice> </group> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 28248c8..f9cd69c 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -11512,14 +11512,6 @@ virDomainRNGDefParseXML(xmlNodePtr node, switch ((virDomainRNGBackend) def->backend) { case VIR_DOMAIN_RNG_BACKEND_RANDOM: def->source.file = virXPathString("string(./backend)", ctxt); - if (def->source.file && - STRNEQ(def->source.file, "/dev/random") && - STRNEQ(def->source.file, "/dev/hwrng")) { - virReportError(VIR_ERR_XML_ERROR, - _("file '%s' is not a supported random source"), - def->source.file); - goto error; - } break; case VIR_DOMAIN_RNG_BACKEND_EGD: diff --git a/tests/qemuxml2argvdata/qemuxml2argv-virtio-rng-random.args b/tests/qemuxml2argvdata/qemuxml2argv-virtio-rng-random.args index ba97c1e..5a4d47b 100644 --- a/tests/qemuxml2argvdata/qemuxml2argv-virtio-rng-random.args +++ b/tests/qemuxml2argvdata/qemuxml2argv-virtio-rng-random.args @@ -18,6 +18,6 @@ QEMU_AUDIO_DRV=none \ -boot c \ -usb \ -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3 \ --object rng-random,id=objrng0,filename=/dev/hwrng \ +-object rng-random,id=objrng0,filename=/dev/urandom \ -device virtio-rng-pci,rng=objrng0,id=rng0,max-bytes=123,period=1234,bus=pci.0,\ addr=0x4 diff --git a/tests/qemuxml2argvdata/qemuxml2argv-virtio-rng-random.xml b/tests/qemuxml2argvdata/qemuxml2argv-virtio-rng-random.xml index 71bd21a..a6e91ff 100644 --- a/tests/qemuxml2argvdata/qemuxml2argv-virtio-rng-random.xml +++ b/tests/qemuxml2argvdata/qemuxml2argv-virtio-rng-random.xml @@ -21,7 +21,7 @@ <memballoon model='virtio'/> <rng model='virtio'> <rate bytes='123' period='1234'/> - <backend model='random'>/dev/hwrng</backend> + <backend model='random'>/dev/urandom</backend> </rng> </devices> </domain> diff --git a/tests/qemuxml2xmloutdata/qemuxml2xmlout-virtio-rng-random.xml b/tests/qemuxml2xmloutdata/qemuxml2xmlout-virtio-rng-random.xml index e8a0478..0bdefde 100644 --- a/tests/qemuxml2xmloutdata/qemuxml2xmlout-virtio-rng-random.xml +++ b/tests/qemuxml2xmloutdata/qemuxml2xmlout-virtio-rng-random.xml @@ -25,7 +25,7 @@ </memballoon> <rng model='virtio'> <rate bytes='123' period='1234'/> - <backend model='random'>/dev/hwrng</backend> + <backend model='random'>/dev/urandom</backend> <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> </rng> </devices>