From: Peter Krempa Date: Thu, 11 Sep 2014 16:35:53 +0200 Subject: CVE-2014-3633: qemu: blkiotune: Use correct definition when looking up disk Live definition was used to look up the disk index while persistent one was indexed leading to a crash in qemuDomainGetBlockIoTune. Use the correct def and report a nice error. Unfortunately it's accessible via read-only connection, though it can only crash libvirtd in the cases where the guest is hot-plugging disks without reflecting those changes to the persistent definition. So avoiding hotplug, or doing hotplug where persistent is always modified alongside live definition, will avoid the out-of-bounds access. Introduced in: eca96694a7f992be633d48d5ca03cedc9bbc3c9aa (v0.9.8) Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1140724 Reported-by: Luyao Huang Signed-off-by: Peter Krempa --- src/qemu/qemu_driver.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 239a300..291f490 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -16141,9 +16141,13 @@ qemuDomainGetBlockIoTune(virDomainPtr dom, } if (flags & VIR_DOMAIN_AFFECT_CONFIG) { - int idx = virDomainDiskIndexByName(vm->def, disk, true); - if (idx < 0) + int idx = virDomainDiskIndexByName(persistentDef, disk, true); + if (idx < 0) { + virReportError(VIR_ERR_INVALID_ARG, + _("disk '%s' was not found in the domain config"), + disk); goto endjob; + } reply = persistentDef->disks[idx]->blkdeviotune; }