classes: cve-check: Get shared database lock

The CVE check database needs to have a shared lock acquired on it before
it is accessed. This to prevent cve-update-db-native from deleting the
database file out from underneath it.

[YOCTO #14899]

(From OE-Core rev: 20a9911b73df62a0d0d1884e57085f13ac5016dd)

Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/cve-check.bbclass

@@ -145,17 +145,18 @@ python do_cve_check () {
     """
     from oe.cve_check import get_patched_cves
 
-    if os.path.exists(d.getVar("CVE_CHECK_DB_FILE")):
-        try:
-            patched_cves = get_patched_cves(d)
-        except FileNotFoundError:
-            bb.fatal("Failure in searching patches")
-        ignored, patched, unpatched, status = check_cves(d, patched_cves)
-        if patched or unpatched or (d.getVar("CVE_CHECK_COVERAGE") == "1" and status):
-            cve_data = get_cve_info(d, patched + unpatched + ignored)
-            cve_write_data(d, patched, unpatched, ignored, cve_data, status)
-    else:
-        bb.note("No CVE database found, skipping CVE check")
+    with bb.utils.fileslocked([d.getVar("CVE_CHECK_DB_FILE_LOCK")], shared=True):
+        if os.path.exists(d.getVar("CVE_CHECK_DB_FILE")):
+            try:
+                patched_cves = get_patched_cves(d)
+            except FileNotFoundError:
+                bb.fatal("Failure in searching patches")
+            ignored, patched, unpatched, status = check_cves(d, patched_cves)
+            if patched or unpatched or (d.getVar("CVE_CHECK_COVERAGE") == "1" and status):
+                cve_data = get_cve_info(d, patched + unpatched + ignored)
+                cve_write_data(d, patched, unpatched, ignored, cve_data, status)
+        else:
+            bb.note("No CVE database found, skipping CVE check")
 
 }