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Fencer Vulns
medium 5.5

CVE-2025-22030 json

mm: zswap: fix crypto_free_acomp() deadlock in zswap_cpu_comp_dead()

published 2025-04-16 18 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-11268

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 9%
public exploits
0
none known

Summary

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

mm: zswap: fix crypto_free_acomp() deadlock in zswap_cpu_comp_dead()

Currently, zswap_cpu_comp_dead() calls crypto_free_acomp() while holding the per-CPU acomp_ctx mutex. crypto_free_acomp() then holds scomp_lock (through crypto_exit_scomp_ops_async()).

On the other hand, crypto_alloc_acomp_node() holds the scomp_lock (through crypto_scomp_init_tfm()), and then allocates memory. If the allocation results in reclaim, we may attempt to hold the per-CPU acomp_ctx mutex.

The above dependencies can cause an ABBA deadlock. For example in the following scenario:

(1) Task A running on CPU #1: crypto_alloc_acomp_node() Holds scomp_lock Enters reclaim Reads per_cpu_ptr(pool->acomp_ctx, 1)

(2) Task A is descheduled

(3) CPU #1 goes offline zswap_cpu_comp_dead(CPU #1) Holds per_cpu_ptr(pool->acomp_ctx, 1)) Calls crypto_free_acomp() Waits for scomp_lock

(4) Task A running on CPU #2: Waits for per_cpu_ptr(pool->acomp_ctx, 1) // Read on CPU #1 DEADLOCK

Since there is no requirement to call crypto_free_acomp() with the per-CPU acomp_ctx mutex held in zswap_cpu_comp_dead(), move it after the mutex is unlocked. Also move the acomp_request_free() and kfree() calls for consistency and to avoid any potential sublte locking dependencies in the future.

With this, only setting acomp_ctx fields to NULL occurs with the mutex held. This is similar to how zswap_cpu_comp_prepare() only initializes acomp_ctx fields with the mutex held, after performing all allocations before holding the mutex.

Opportunistically, move the NULL check on acomp_ctx so that it takes place before the mutex dereference.

Patch / fix

  • Linux Linux 6.12.23, 6.13.11, 6.14.2, 6.15
  • linux Debian 14, Debian 13 6.12.25-1

debian advisories DEBIAN-CVE-2025-22030

  • linux-gcp-6.11 Ubuntu 24.04 LTS 6.11.0-1016.16~24.04.1
  • linux-hwe-6.11 Ubuntu 24.04 LTS 6.11.0-28.28~24.04.1
  • linux-oem-6.11 Ubuntu 24.04 LTS 6.11.0-1024.24
  • linux-azure-6.11 Ubuntu 24.04 LTS 6.11.0-1018.18~24.04.1
  • linux-nvidia-6.11 Ubuntu 24.04 LTS 6.11.0-1012.12
  • linux-lowlatency-hwe-6.11 Ubuntu 24.04 LTS 6.11.0-1015.16~24.04.2

ubuntu advisories UBUNTU-CVE-2025-22030

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

  • dtb-aarch64 openSUSE Leap 15.6 6.4.0-150600.23.53.1
  • kernel-64kb SLE Module for Basesystem 15 SP6, openSUSE Leap 15.6 6.4.0-150600.23.53.1
  • kernel-syms SLE Module for Development Tools 15 SP6, openSUSE Leap 15.6 6.4.0-150600.23.53.1
  • kernel-obs-qa openSUSE Leap 15.6 6.4.0-150600.23.53.1
  • kernel-source SLE Module for Development Tools 15 SP6, SLE Module for Basesystem 15 SP6, openSUSE Leap 15.6 6.4.0-150600.23.53.1
  • kernel-default SLE Workstation Extension 15 SP6, SLE Module for Legacy 15 SP6, SLE Module for Basesystem 15 SP6 +3 more 6.4.0-150600.23.53.1
  • kernel-kvmsmall openSUSE Leap 15.6 6.4.0-150600.23.53.1
  • kernel-zfcpdump SLE Module for Basesystem 15 SP6, openSUSE Leap 15.6 6.4.0-150600.23.53.1

suse advisories SUSE-SU-2025:02000-1SUSE-SU-2025:01972-1SUSE-SU-2025:20413-1SUSE-SU-2025:01967-1SUSE-SU-2025:01965-1SUSE-SU-2025:01964-1

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-2025-22030 updated cvss 5.5

kernel: mm: zswap: fix crypto_free_acomp() deadlock in zswap_cpu_comp_dead()

  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 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

0.20% chance of exploitation in the next 30 days, higher than 9% 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

Weakness
Technology feeds

References

Sources

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