https://bugzilla.redhat.com/show_bug.cgi?id=876828 Commit 38c4a9cc introduced a regression in hot unplugging of disks from qemu, where cgroup device ACLs were no longer being revoked (thankfully not a security hole: cgroup ACLs only prevent open() of the disk; so reverting the ACL prevents future abuse but doesn't stop abuse from an fd that was already opened before the ACL change). Commit 1b2ebf95 overlooked that there were two spots affected. * src/qemu/qemu_hotplug.c (qemuDomainDetachDiskDevice): Transfer backing chain before deletion. * src/qemu/qemu_driver.c (qemuDomainDetachDeviceDiskLive): Fix spacing (partly to ensure a different-looking patch). --- I blame git for letting me find this - I did a 'pull --rebase' on top of libvirt.git, and noticed that my working patch was still on the tree - it turns out that the hunk for qemu_hotplug.c is _identical_ except for the context of the function name needing a fix. I still wish git would be more vocal when it finds an alternate place to apply a patch when function names don't match. src/qemu/qemu_driver.c | 2 +- src/qemu/qemu_hotplug.c | 2 ++ 2 files changed, 3 insertions(+), 1 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index c37bdb9..ae98dbf 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -6070,7 +6070,7 @@ qemuDomainDetachDeviceDiskLive(virQEMUDriverPtr driver, if (disk->bus == VIR_DOMAIN_DISK_BUS_VIRTIO) ret = qemuDomainDetachPciDiskDevice(driver, vm, dev); else if (disk->bus == VIR_DOMAIN_DISK_BUS_SCSI) - ret = qemuDomainDetachDiskDevice(driver, vm, dev); + ret = qemuDomainDetachDiskDevice(driver, vm, dev); else if (dev->data.disk->bus == VIR_DOMAIN_DISK_BUS_USB) ret = qemuDomainDetachDiskDevice(driver, vm, dev); else diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c index cfeae68..2d4a822 100644 --- a/src/qemu/qemu_hotplug.c +++ b/src/qemu/qemu_hotplug.c @@ -2091,6 +2091,8 @@ int qemuDomainDetachDiskDevice(virQEMUDriverPtr driver, virDomainDiskRemove(vm->def, i); + dev->data.disk->backingChain = detach->backingChain; + detach->backingChain = NULL; virDomainDiskDefFree(detach); if (virSecurityManagerRestoreImageLabel(driver->securityManager, -- 1.7.1