Re: [libvirt] [PATCH] audit: eliminate potential null pointer deref when auditing macvtap devices

On 03/14/2011 09:18 AM, Laine Stump wrote: > The newly added call to qemuAuditNetDevice in qemuPhysIfaceConnect was > assuming that res_ifname (the name of the macvtap device) was always > valid, but this isn't the case. If openMacvtapTap fails, it always > returns NULL, which would result in a segv. > > Since the audit log only needs a record of devices that are actually > sent to qemu, and a failure to open the macvtap device means that no > device will be sent to qemu, we can solve this problem by only doing > the audit if openMacvtapTap is successful (in which case res_ifname is > guaranteed valid). > --- > src/qemu/qemu_command.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c > index 8ca656a..72f55d0 100644 > --- a/src/qemu/qemu_command.c > +++ b/src/qemu/qemu_command.c > @@ -128,8 +128,8 @@ qemuPhysIfaceConnect(virDomainDefPtr def, > net->data.direct.mode, vnet_hdr, def->uuid, > &net->data.direct.virtPortProfile,&res_ifname, > vmop); > - qemuAuditNetDevice(def, net, res_ifname, rc>= 0); > if (rc>= 0) { > + qemuAuditNetDevice(def, net, res_ifname, true); > VIR_FREE(net->ifname); > net->ifname = res_ifname; > } ACK.