The POWER9 backend in GNU Compiler Collection (GCC) before version 10 could optimize multiple calls of the __builtin_darn intrinsic into a single call, thus reducing the entropy of the random number generator. This occurred because a volatile operation was not specified. For example, within a single execution of a program, the output of every __builtin_darn() call may be the same.
Fix
Patch, vendor advisory and mitigation references on NVD 2
- https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91481 Issue Tracking, Vendor Advisory
- https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91481 Issue Tracking, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 7.5 · gnu, opensuseNVD modified 2026-10-14 07:16
Affected (CPE criteria) 3
cpe:2.3:a:gnu:gcc:*:*:*:*:*:*:*:*cpe:2.3:o:opensuse:leap:15.0:*:*:*:*:*:*:*cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*
References 9
- http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00056.html Mailing List, Third Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00057.html Mailing List, Third Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00058.html Mailing List, Third Party Advisory
- https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91481 Issue Tracking, Vendor Advisory
- http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00056.html Mailing List, Third Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00057.html Mailing List, Third Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00058.html Mailing List, Third Party Advisory
- https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91481 Issue Tracking, Vendor Advisory
- https://cert-portal.siemens.com/productcert/html/ssa-398330.html