From: Eric Blake Date: Fri, 3 Jun 2011 19:53:26 +0000 (-0600) Subject: python: avoid unlikely sign extension bug X-Git-Tag: v0.9.3-rc1~213 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f73198df;p=thirdparty%2Flibvirt.git python: avoid unlikely sign extension bug Detected by Coverity. cpumap was allocated with a value of (unsigned short)*(int), which is an int computation, and then promotes to size_t. On a 64-bit platform, this fails if bit 32 of the product is set (because of sign extension giving a HUGE value to malloc), even though a naive programmer would assume that since the first value is unsigned, the product is also unsigned and at most 4GB would be allocated. Won't bite in practice (the product should never be that large), but worth using the right types to begin with, so that we are now computing (unsigned short)*(size_t). * python/libvirt-override.c (libvirt_virDomainGetVcpus): Use correct type. --- diff --git a/python/libvirt-override.c b/python/libvirt-override.c index 763df0028e..974decb68c 100644 --- a/python/libvirt-override.c +++ b/python/libvirt-override.c @@ -414,7 +414,7 @@ libvirt_virDomainGetVcpus(PyObject *self ATTRIBUTE_UNUSED, virDomainInfo dominfo; virVcpuInfoPtr cpuinfo = NULL; unsigned char *cpumap = NULL; - int cpumaplen, i; + size_t cpumaplen, i; int i_retval; if (!PyArg_ParseTuple(args, (char *)"O:virDomainGetVcpus",