It was found that it is possible for root to gain direct access to an internal keyring, such as '.dns_resolver' in RHEL-7 or '.builtin_trusted_keys' upstream, by joining it as its session keyring. This allows root to bypass module signature verification by adding a new public key of its own devising to the keyring. References: https://bugzilla.novell.com/show_bug.cgi?id=1035576 http://people.canonical.com/~ubuntu-security/cve/2016/CVE-2016-9604.html Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ee8f844e3c5a73b999edf733df1c529d6503ec2f
Acknowledgments: Name: David Howells (Red Hat)
Statement: This issue does not affect the Linux kernel packages as shipped with Red Hat Enterprise Linux 5 as the code with the flaw is not present in this product. This issue affects the Linux kernel packages as shipped with Red Hat Enterprise Linux 6, 7 and MRG-2. Future Linux kernel updates for the respective releases might address this issue.
Created kernel tracking bugs for this issue: Affects: fedora-all [bug 1446566]
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2017:2077 https://access.redhat.com/errata/RHSA-2017:2077
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2017:1842 https://access.redhat.com/errata/RHSA-2017:1842
This issue has been addressed in the following products: Red Hat Enterprise MRG 2 Via RHSA-2017:2669 https://access.redhat.com/errata/RHSA-2017:2669