Description
It was discovered in the Linux kernel before 4.11-rc8 that root can 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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| kernel | security | kernel 4.11-rc8 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 4.9.25-1 | — |
| Debian 13 | linux | 4.9.25-1 | — |
| Debian 12 | linux | 4.9.25-1 | — |
| Debian 7 | linux | 3.2.88-1 | DLA-922-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | linux-gcp-6.11 +4 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv +2 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-gke +3 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +4 | No fix yet | — |
| Ubuntu 16.04 LTS | linux | 4.4.0-79.100 | USN-3312-1 |
| Ubuntu 16.04 LTS | linux-aws | 4.4.0-1018.27 | USN-3312-1 |
| Ubuntu 16.04 LTS | linux-gke | 4.4.0-1014.14 | USN-3312-1 |
| Ubuntu 16.04 LTS | linux-hwe | 4.10.0-32.36~16.04.1 | USN-3361-1 |
| Ubuntu 16.04 LTS | linux-raspi2 | 4.4.0-1057.64 | USN-3312-1 |
| Ubuntu 16.04 LTS | linux-snapdragon | 4.4.0-1059.63 | USN-3312-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | linux | 3.13.0-132.181 | USN-3422-1 |
| Ubuntu 14.04 LTS | linux-lts-xenial | 4.4.0-79.100~14.04.1 | USN-3312-2 |
| Ubuntu Pro 20.04 LTS | linux-azure-fde-5.15 | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | kernel-rt +10 | 3.10.0-693.rt56.617.el7 | RHSA-2017:2077 |
| RHEL 7 | perf +17 | 3.10.0-693.el7 | RHSA-2017:1842 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat MRG 2 | kernel-rt +10 | 1:3.10.0-693.2.1.rt56.585.el6rt | RHSA-2017:2669 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP1 | kernel-docs | 3.12.74-60.64.40.4 | SUSE-SU-2017:1360-1 |
| SLES 12 SP1 | kernel-xen +4 | 3.12.74-60.64.40.1 | SUSE-SU-2017:1360-1 |
| SLES 12 | kernel-ec2 +4 | 3.12.61-52.101.1 | SUSE-SU-2017:2920-1, SUSE-SU-2017:1360-1 |
| SLES 12 | kgraft-patch-SLE12_Update_28 | 1-8.1 | SUSE-SU-2017:2920-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP1 | kernel-xen +3 | 3.12.74-60.64.40.1 | SUSE-SU-2017:1360-1 |
| SLE Live Patching 12 | kgraft-patch-SLE12-SP1_Update_15 | 1-4.1 | SUSE-SU-2017:1360-1 |
Advisories 10
- RHSA-2017:2669 Red Hat Security Advisory: kernel-rt security and bug fix update Red Hat Security Advisories (RHSA) · Jul 1, 2026
- RHSA-2017:2077 Red Hat Security Advisory: kernel-rt security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Jul 1, 2026
- RHSA-2017:1842 Red Hat Security Advisory: kernel security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Jul 1, 2026
- USN-3361-1 linux-hwe vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- USN-3422-1 linux vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-3312-1 linux, linux-aws, linux-gke, linux-raspi2, linux-snapdragon vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DLA-922-1 linux - security update Debian Security (DSA / DLA) · Mar 9, 2026
- USN-3312-2 linux-lts-xenial vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- SUSE-SU-2017:1360-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2017:2920-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
References
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ee8f844e3c5a73b999edf733df1c529d6503ec2f
- RHSA-2017:2669 vendor-advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2016-9604
- https://bugzilla.novell.com/show_bug.cgi?id=1035576
- http://people.canonical.com/~ubuntu-security/cve/2016/CVE-2016-9604.html
- 102135 vdb-entry
- RHSA-2017:2077 vendor-advisory
- RHSA-2017:1842 vendor-advisory