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Fencer Vulns
medium 5.5

CVE-2022-49709 json

cfi: Fix __cfi_slowpath_diag RCU usage with cpuidle

published 2025-02-26 20 mo ago modified 2026-06-17 4 mo ago also EUVD-2022-54526

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 17%
public exploits
0
none known

Summary

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

cfi: Fix __cfi_slowpath_diag RCU usage with cpuidle

RCU_NONIDLE usage during __cfi_slowpath_diag can result in an invalid RCU state in the cpuidle code path:

WARNING: CPU: 1 PID: 0 at kernel/rcu/tree.c:613 rcu_eqs_enter+0xe4/0x138 ... Call trace: rcu_eqs_enter+0xe4/0x138 rcu_idle_enter+0xa8/0x100 cpuidle_enter_state+0x154/0x3a8 cpuidle_enter+0x3c/0x58 do_idle.llvm.6590768638138871020+0x1f4/0x2ec cpu_startup_entry+0x28/0x2c secondary_start_kernel+0x1b8/0x220 __secondary_switched+0x94/0x98

Instead, call rcu_irq_enter/exit to wake up RCU only when needed and disable interrupts for the entire CFI shadow/module check when we do.

Patch / fix

  • Linux Linux 5.15.49, 5.18.6, 5.19
  • linux Debian 14, Debian 13, Debian 12 5.18.14-1

debian advisories DEBIAN-CVE-2022-49709

  • linux Ubuntu 22.04 LTS 5.15.0-48.54
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1020.24
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1018.24
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1016.19
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1015.17
  • linux-kvm Ubuntu 22.04 LTS 5.15.0-1018.22
  • linux-azure Ubuntu 22.04 LTS 5.15.0-1020.25
  • linux-gkeop Ubuntu 22.04 LTS 5.15.0-1003.5

ubuntu advisories UBUNTU-CVE-2022-49709

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

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-2022-49709 updated

kernel: cfi: Fix __cfi_slowpath_diag RCU usage with cpuidle

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more 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
    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

0.26% chance of exploitation in the next 30 days, higher than 17% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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.