Re: [libvirt] [PATCH 3/7] vbox: avoid problematic uses of sprintf

* src/vbox/vbox_tmpl.c (vboxStartMachine, vboxAttachUSB): Use virAsprintf instead. --- This removes all use of sprintf in vbox.  The first 3 use virAsprintf (DISPLAY may be arbitrarily long, and while we are unlikely to hit 9999 devices, it's better to be safe than to risk silent buffer overflow); the remaining two are sized appropriately (actually, they are sized too large, the real boundary size would be sizeof(int)*2+1 rather than 40); I felt better using snprintf rather than sprintf. This doesn't address the fact that vbox doesn't really have very good OOM handling (ie. it keeps on trying, although after the first OOM, it will likely get another one); but that is an independent issue.

@@ -4457,15 +4466,19 @@ vboxAttachUSB(virDomainDefPtr def, vboxGlobalData *data, IMachine *machine)                     if (def->hostdevs[i]->source.subsys.type ==                         VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_USB) { -                        char filtername[11]        = {0}; +                        char *filtername           = NULL;                         PRUnichar *filternameUtf16 = NULL;                         IUSBDeviceFilter *filter   = NULL; -                        /* Assuming can't have more then 9999 devices so -                         * restricting to %04d +                        /* Zero pad for nice alignment when fewer than 9999 +                         * devices.                          */ -                        sprintf(filtername, "filter%04d", i); -                        VBOX_UTF8_TO_UTF16(filtername, &filternameUtf16); +                        if (virAsprintf(&filtername, "filter%04d", i) < 0) { +                            virReportOOMError(); +                        } else { +                            VBOX_UTF8_TO_UTF16(filtername, &filternameUtf16); +                            VIR_FREE(filtername); +                        }                         USBController->vtbl->CreateDeviceFilter(USBController,                                                                 filternameUtf16,