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Fencer Vulns
no cvss —

CVE-2026-99222 json

keys: Protect the read method check against type removal

published 2026-11-02 6 d ago modified 2026-11-03 5 d ago also EUVD-2026-115264

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 7%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

keys: Protect the read method check against type removal

keyctl_read_key() checks key->type->read without holding key->sem. A reference keeps the key alive, but does not pin the module containing its type. A surviving RxRPC key can therefore be read while AF_RXRPC is being unloaded:

KEYCTL_READ task Module unload and key GC ---------------- ------------------------ lookup_user_key() permission / possession checks load key->type af_rxrpc_exit() unregister_key_type() GC: down_write(key->sem) GC: retype to key_type_dead GC: up_write(key->sem) unregister_key_type() returns free_module() read saved type's read member

The final access can read freed module storage. The read invocation in __keyctl_read_key() is already protected by key->sem, but the earlier method check is outside that critical section.

Move the method check into __keyctl_read_key(), after key_validate() and under its existing read hold on key->sem. The check and invocation then use the same protected type for length queries and every read retry. The GC cannot retype the key until the semaphore is released, and type unregistration waits for that GC pass before the module can be freed.

Return -EOPNOTSUPP when validation succeeds and the type has no read method. A temporary buffer may now be allocated before this result; allocation and copying to userspace remain outside the semaphore.

Patch / fix

  • Linux Linux 4.15, 4.20, 5.5, 5.7, 5.10.273, 5.15.224, 6.1.191, 6.6.161, 6.12.115, 6.18.60, 7.2.14, 7.3.1, 7.4-rc1
  • linux Debian 13 6.12.115-1
  • linux Debian 14 7.2.14-1

debian advisories DEBIAN-CVE-2026-99222

  • kernel Azure Linux 3.0 6.6.161.1-1

azure linux advisories AZL-112544

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-99222 updated cvss 4.7

kernel: kernel: Denial of Service via use-after-free in keyctl_read_key

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9, openshift/ose-rhel-coreos-10
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.