On 08/29/2012 10:49 AM, Kyle Mestery (kmestery) wrote:
On Aug 29, 2012, at 6:19 AM, Alex Jia wrote:
On 08/29/2012 06:43 PM, Laine Stump wrote:
This bug was revealed by the crash described in
https://bugzilla.redhat.com/show_bug.cgi?id=852383
The vlan info pointer sent to virNetDevOpenvswitchAddPort should never be non-NULL unless there is at least one tag. The factthat such a vlan info pointer was receveid pointed out that a caller was passing the wrong pointer. Instead of sending&net->vlan, the result of virDomainNetGetActualVlan(net) should be sent - that function will look for vlan info in net->data.network.actual->vlan, and in cany case return NULL instead of a pointer if the vlan info it finds has no tags.
Aside from causing the crash, sending a hardcoded&net->vlan has the effect of ignoring vlan info from a<network> or<portgroup> config. ---
Since I'm not online in a regular fashion for the next few days (too bad I wasn't online in the 12 hours or so *before* the 0.10.0 release instead of after :-/), I would appreciate if whoever ACKs this could push it. Thanks! Laine, unfortunately, the libvirtd still is crash without my patch after applying your patch :(
Hi Alex and Laine:
What I notice is, that with Laine's patch, for virtualport of type openvswitch, if I do NOT define a VLAN, it crashes. If I do, then I can start my virtual machines. Without Laine's patch, it's the same, which leads me to believe Laine's patch only fixes a symptom of this issue.
No, there are actually two separate crashes and two separate issues - look at the two tracebacks in https://bugzilla.redhat.com/show_bug.cgi?id=852383 - they are different at the very top. One crash is due to improper buf usage, and the other due to a bad vlan pointer. The first doesn't show up until the second is fixed (or masked by checking for vlan->nTags > 0). And again, while the checking for vlan->nTags > 0 isn't a bad thing, doing that just masks the symptom of the "original" real issue, which was us sending &net->vlan rather than calling virDomainNetGetActualVlan().