support/scripts/pkg-stats: account for unsure CVEs

The .affects() method of the CVE class in support/scripts/cve.py can
return 3 values: CVE_AFFECTS, CVE_DOESNT_AFFECT and CVE_UNKNOWN.

We of course properly account for CVEs where .affects() return
CVE_AFFECTS, but the ones for which CVE_UNKNOWN is returned are
currently ignored, and therefore treated as if they did not affect the
package.

However CVE_UNKNOWN in fact indicates that the v_start/v_end fields of
the CPE entry could not be parsed by
distutils.version.LooseVersion(). Instead of ignoring such cases, this
commit adds support for the concept of "unsure CVEs", which will be
listed next to CVEs known to affect the package, so that we are aware
of them and can investigate the version issue.

Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit a206bbc5fe3453f8763268261c4a7aa6ba2c275d)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

support/scripts/pkg-stats

@@ -101,6 +101,7 @@ class Package:
         self.cpeid = None
         self.cves = list()
         self.ignored_cves = list()
+        self.unsure_cves = list()
         self.latest_version = {'status': RM_API_STATUS_ERROR, 'version': None, 'id': None}
         self.status = {}
 
@@ -569,8 +570,11 @@ def check_package_cve_affects(cve, cpe_product_pkgs):
         if product not in cpe_product_pkgs:
             continue
         for pkg in cpe_product_pkgs[product]:
-            if cve.affects(pkg.name, pkg.current_version, pkg.ignored_cves, pkg.cpeid) == cve.CVE_AFFECTS:
+            cve_status = cve.affects(pkg.name, pkg.current_version, pkg.ignored_cves, pkg.cpeid)
+            if cve_status == cve.CVE_AFFECTS:
                 pkg.cves.append(cve.identifier)
+            elif cve_status == cve.CVE_UNKNOWN:
+                pkg.unsure_cves.append(cve.identifier)
 
 
 def check_package_cves(nvd_path, packages):
@@ -596,7 +600,7 @@ def check_package_cves(nvd_path, packages):
 
     for pkg in packages:
         if 'cve' not in pkg.status:
-            if pkg.cves:
+            if pkg.cves or pkg.unsure_cves:
                 pkg.status['cve'] = ("error", "affected by CVEs")
             else:
                 pkg.status['cve'] = ("ok", "not affected by CVEs")
@@ -651,8 +655,11 @@ def calculate_stats(packages):
             stats["version-not-uptodate"] += 1
         stats["patches"] += pkg.patch_count
         stats["total-cves"] += len(pkg.cves)
+        stats["total-unsure-cves"] += len(pkg.unsure_cves)
         if len(pkg.cves) != 0:
             stats["pkg-cves"] += 1
+        if len(pkg.unsure_cves) != 0:
+            stats["pkg-unsure-cves"] += 1
         if pkg.cpeid:
             stats["cpe-id"] += 1
         else:
@@ -904,6 +911,8 @@ def dump_html_pkg(f, pkg):
     if pkg.is_status_error("cve"):
         for cve in pkg.cves:
             f.write("   <a href=\"https://security-tracker.debian.org/tracker/%s\">%s<br/>\n" % (cve, cve))
+        for cve in pkg.unsure_cves:
+            f.write("   <a href=\"https://security-tracker.debian.org/tracker/%s\">%s <i>(unsure)</i><br/>\n" % (cve, cve))
     elif pkg.is_status_na("cve"):
         f.write("    %s" % pkg.status['cve'][1])
     else:
@@ -986,6 +995,10 @@ def dump_html_stats(f, stats):
             stats["pkg-cves"])
     f.write("<tr><td>Total number of CVEs affecting all packages</td><td>%s</td></tr>\n" %
             stats["total-cves"])
+    f.write("<tr><td>Packages affected by unsure CVEs</td><td>%s</td></tr>\n" %
+            stats["pkg-unsure-cves"])
+    f.write("<tr><td>Total number of unsure CVEs affecting all packages</td><td>%s</td></tr>\n" %
+            stats["total-unsure-cves"])
     f.write("<tr><td>Packages with CPE ID</td><td>%s</td></tr>\n" %
             stats["cpe-id"])
     f.write("<tr><td>Packages without CPE ID</td><td>%s</td></tr>\n" %