[libvirt] [PATCH] Don't crash if a connection closes early

[Jiri Denemark]

On Fri, Jan 10, 2014 at 13:27:49 -0700, Eric Blake wrote:
> On 01/10/2014 12:19 PM, Jiri Denemark wrote:
> > https://bugzilla.redhat.com/show_bug.cgi?id=1047577
> > 
> > When a client closes its connection to libvirtd early during
> > virConnectOpen, more specifically just after making
> > REMOTE_PROC_CONNECT_SUPPORTS_FEATURE call to check if
> > VIR_DRV_FEATURE_PROGRAM_KEEPALIVE is supported without even waiting for
> > the result, libvirtd may crash due to a race in keep-alive
> > initialization. Once receiving the REMOTE_PROC_CONNECT_SUPPORTS_FEATURE
> > call, the daemon's event loop delegates it to a worker thread. In case
> > the event loop detects EOF on the connection and calls
> > virNetServerClientClose before the worker thread starts to handle
> > REMOTE_PROC_CONNECT_SUPPORTS_FEATURE call, client->keepalive will be
> > disposed by the time virNetServerClientStartKeepAlive gets called from
> > remoteDispatchConnectSupportsFeature. Because the flow is common for
> > both authenticated and read-only connections, even unprivileged clients
> > may cause the daemon to crash.
> > 
> > To void the crash, virNetServerClientStartKeepAlive needs to check if
> 
> s/void/avoid/
> 
> > the connection is still open before starting keep-alive protocol.
> > 
> > Every libvirt release since 0.9.8 is affected by this bug.
> > 
> > Signed-off-by: Jiri Denemark <jdenemar at redhat.com>
> > ---
> >  src/rpc/virnetserverclient.c | 15 ++++++++++++++-
> >  1 file changed, 14 insertions(+), 1 deletion(-)
> 
> ACK.  Definitely worth having in 1.2.1.

Pushed, thanks.

Jirka