[libvirt] [PATCH] qemudDomainAttachSCSIDisk: handle empty controller list

Clang found something that might be a real bug. I suspect that ...drive.controller will always be at least one, but we should not have to dive into the code trying to figure that out. It's easier/better here just to handle the potential trouble: clang saw that if it *was* zero, then the following "for" loop would not be entered, and "cont" would not be initialized. On the very next statement "cont" (uninitialized) would be dereferenced. From: Jim Meyering <meyering(a)redhat.com&gt; Date: Tue, 2 Mar 2010 17:45:10 +0100 Subject: [PATCH] qemudDomainAttachSCSIDisk: handle empty controller list * src/qemu/qemu_driver.c (qemudDomainAttachSCSIDisk): Handle the (theoretical) case of an empty controller list, so that clang does not think the subsequent dereference of "cont" would dereference an undefined variable (due to preceding loop not iterating even once). --- src/qemu/qemu_driver.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 7f7c459..efb1857 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -5671,18 +5671,24 @@ static int qemudDomainAttachSCSIDisk(struct qemud_driver *driver, if (qemuAssignDeviceDiskAlias(disk, qemuCmdFlags) < 0) goto error; if (!(devstr = qemuBuildDriveDevStr(disk))) goto error; } if (!(drivestr = qemuBuildDriveStr(disk, 0, qemuCmdFlags))) goto error; + if (disk->info.addr.drive.controller <= 0) { + qemuReportError(VIR_ERR_INTERNAL_ERROR, + _("no drive controller for %s"), disk->dst); + goto error; + } + for (i = 0 ; i <= disk->info.addr.drive.controller ; i++) { cont = qemuDomainFindOrCreateSCSIDiskController(driver, vm, i, qemuCmdFlags); if (!cont) goto error; } if (cont->info.type != VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI) { qemuReportError(VIR_ERR_INTERNAL_ERROR, _("SCSI controller %d was missing its PCI address"), cont->idx); -- 1.7.0.1.414.g89213d