Copyright © 2012 Red Hat, Inc. All rights reserved. Low 2026-11-02T16:06:33 kernel: kernel: Information disclosure via predictable keyring index ordering 3.3 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N CWE-204

In the Linux kernel, the following vulnerability has been resolved: keys: make keyring indexes independent of kernel addresses KEYCTL_READ returns the serial numbers in a keyring in associative-array traversal order. The first word of the index is a public, deterministic hash of the type pointer, domain pointer and description. An unprivileged user can therefore insert keys with known descriptions, predict their order for each possible KASLR slide, and recover the kernel image address. On an x86-64 build with 16 MiB alignment, 45 user keys suffice to distinguish the candidate slides. Remove the addresses from the whole index, not just its first hash word. Assign each key type and domain a nonzero 64-bit ID and hash those IDs and the description with a once-initialized SipHash key. Use the full IDs in the later index chunks as well. Truncating or hashing the IDs there would lose the guarantee that distinct type/domain/description tuples have a differing index bit. Allocate IDs lazily since private key types need not be registered. Cache them in the index key so tree walks and copies of an existing index do not need to dereference a type descriptor that may have been unregistered. Keep the 32-bit chunk layout and diff_objects() bit offsets consistent, and retain the separate root slot for keyrings used by recursive search. The key comparison, permissions and userspace data format are unchanged; only the address-dependent in-memory ordering is replaced.

A flaw was found in the Linux kernel. A local unprivileged attacker can exploit this flaw to cause an information disclosure by inserting keys with known descriptions into a keyring and observing the order in which they are retrieved. Because internal keyring indexing relies on memory addresses, analyzing this predictable traversal order allows the attacker to deduce the kernel memory layout and bypass Kernel Address Space Layout Randomization (KASLR).

Red Hat Enterprise Linux 10 Fix deferred kernel Red Hat Enterprise Linux 6 Out of support scope kernel Red Hat Enterprise Linux 7 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel-rt Red Hat Enterprise Linux 8 Fix deferred kernel Red Hat Enterprise Linux 8 Fix deferred kernel-rt Red Hat Enterprise Linux 9 Fix deferred kernel Red Hat Enterprise Linux 9 Fix deferred kernel-rt Red Hat OpenShift Container Platform 4 Fix deferred openshift/ose-rhel-coreos-8 Red Hat OpenShift Container Platform 4 Fix deferred openshift/ose-rhel-coreos-9 Red Hat OpenShift Container Platform 5 Fix deferred openshift/ose-rhel-coreos-10 Red Hat OpenShift Container Platform 5 Fix deferred openshift/ose-rhel-coreos-9 https://www.cve.org/CVERecord?id=CVE-2026-99223 https://nvd.nist.gov/vuln/detail/CVE-2026-99223 https://git.kernel.org/stable/c/13fc051269d670810d9e314061b61c6dd06116a0 https://git.kernel.org/stable/c/61ac0585d9f4344d3dfb84b5edff1fee7d532897 https://git.kernel.org/stable/c/8451d4a4c43127c3b9fdf9fc9ff3fea5539a61f9 https://git.kernel.org/stable/c/84f7c699f8d139f743c7dc11ef41d085690955bb https://git.kernel.org/stable/c/9ebe824d55983c9f063a2c9ef1a08b29812d406f https://git.kernel.org/stable/c/9f084ef0beb68091e96ab96f0e95579aac8a77f9 https://git.kernel.org/stable/c/a113eba06bd1183c614d7994864d6e7054140cb9 https://git.kernel.org/stable/c/e108b22999edbc6f431466baf6b2016c19b7ed31