Re: [libvirt] [PATCH 1/2] network: make networkCreateInterfacePool more robust

networkCreateInterfacePool was a bit loose in its error cleanup, which could result in a network definition with interfaces in the pool that were NULL. This would in turn lead to a libvirtd crash when a guest tried to attach an interface using the network with that pool. In particular this would happen when creating a pool to be used for macvtap connections. macvtap needs the netdev name of the virtual function in order to use it, and each VF only has a netdev name if it is currently bound to a network driver. If one of the VFs of a PF happened to be bound to the pci-stub or vfio-pci driver (indicating it's already in use for PCI passthrough), or no driver at all, it would have no name. In this case networkCreateInterfacePool would return an error, but would leave the netdef->forward.nifs set to the total number of VFs in the PF. The interface attach that triggered calling of networkCreateInterfacePool (it uses a "lazy fill" strategy) would simply fail, but the very next attempt to attach an interface using the same network pool would result in a crash. This patch refactors networkCreateInterfacePool to bring it more in line with current coding practices (label name, use of a switch with no default case) as well as providing the following two changes to behavior: 1) If a VF with no netdev name is encountered, just log a warning and continue; only fail if exactly 0 devices are found to put in the pool. 2) If the function fails, clean up any partial interface pool and set netdef->forward.nifs to 0. This resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1111455 --- src/network/bridge_driver.c | 113 ++++++++++++++++++++++++++++---------------- 1 file changed, 73 insertions(+), 40 deletions(-)

+ cleanup: + if (ret < 0) { + /* free all the entries made before error */ + for (i= 0; i < netdef->forward.nifs; i++) {