Intel

CVE-2026-64418

Linux kernel (GCP) vulnerabilities

highEPSS 0.1%

Description

In the Linux kernel, the following vulnerability has been resolved: mm: shrinker: fix shrinker_info teardown race with expansion expand_shrinker_info() iterates all visible memcgs under shrinker_mutex, including memcgs that have not finished ->css_online() yet. Once pn->shrinker_info has been published, teardown must stay serialized with expand_shrinker_info() until that memcg is either fully online or no longer visible to iteration. Today alloc_shrinker_info() breaks that rule by dropping shrinker_mutex before freeing a partially initialized shrinker_info array, which may cause the following race: CPU0 CPU1 ==== ==== css_create --> list_add_tail_rcu(&css->sibling, &parent_css->children); online_css --> mem_cgroup_css_online --> alloc_shrinker_info --> alloc node0 info rcu_assign_pointer(C->node0->shrinker_info, old0) alloc node1 info -> FAIL -> goto err mutex_unlock(shrinker_mutex) shrinker_alloc() --> shrinker_memcg_alloc --> mutex_lock(shrinker_mutex) expand_shrinker_info --> mem_cgroup_iter see the memcg expand_one_shrinker_info --> old0 = C->node0->shrinker_info memcpy(new->unit, old0->unit, ...); free_shrinker_info --> kvfree(old0); /* double free !! */ kvfree_rcu(old0, rcu); The same problem exists later in mem_cgroup_css_online(). If alloc_shrinker_info() succeeds but a subsequent objcg allocation fails, the free_objcg -> free_shrinker_info() unwind path tears down the already published pn->shrinker_info arrays without shrinker_mutex. The expand_one_shrinker_info() can race with that teardown in the same way, leading to use-after-free or double-free of the old shrinker_info. Fix this by serializing shrinker_info teardown with shrinker_mutex, and by keeping alloc_shrinker_info() error cleanup inside the locked section.

Source: UBUNTU_USNUBUNTU_USNUBUNTU_USNBSIBSI_CSAFNVDCVELISTV5

Metrics

Severity
high
Priority score
231.31
KEV status
—
Exploit maturity
no public PoC known
XIEM Effective CVSS
7.8
Source: nvd-v3
CVSS v3
7.8
CVSS v4
—
EPSS percentile
0.8 %
Low — this CVE sits in the lower 10% of all CVEs scored today.
EPSS score
0.1 %
Low — model estimates < 1% exploitation likelihood.
Published
2026-09-07 09:05 UTC
CWE
—

Reanalysis & status changes

Chronological NVD audit events for this CVE — reanalyses, CVSS updates, CPE diffs.

  1. CVE Modified2026-08-17 05:17 UTC· 416baaa9-dc9f-4396-8d5f-8c081fb06d67
    • Affected: Linux, Linux → Linux, Linux
  2. New CVE Received2026-07-25 10:17 UTC· 416baaa9-dc9f-4396-8d5f-8c081fb06d67
    • Affected: Linux, Linux
    • Description: In the Linux kernel, the following vulnerability has been resolved: mm: shrinker: fix shrinker_info teardown race with expansion expand_shrinker_info() iterates all visible memcgs under shrinker_mutex, including memcgs that have not finished ->css_online() yet. Once pn->shrinker_info has been published, teardown must stay serialized with expand_shrinker_info() until that memcg is either fully online or no longer visible to iteration. Today alloc_shrinker_info() breaks that rule by dropping shrinker_mutex before freeing a partially initialized shrinker_info array, which may cause the following race: CPU0 CPU1 ==== ==== css_create --> list_add_tail_rcu(&css->sibling, &parent_css->children); online_css --> mem_cgroup_css_online --> alloc_shrinker_info --> alloc node0 info rcu_assign_pointer(C->node0->shrinker_info, old0) alloc node1 info -> FAIL -> goto err mutex_unlock(shrinker_mutex) shrinker_alloc() --> shrinker_memcg_alloc --> mutex_lock(shrinker_mutex) expand_shrinker_info --> mem_cgroup_iter see the memcg expand_one_shrinker_info --> old0 = C->node0->shrinker_info memcpy(new->unit, old0->unit, ...); free_shrinker_info --> kvfree(old0); /* double free !! */ kvfree_rcu(old0, rcu); The same problem exists later in mem_cgroup_css_online(). If alloc_shrinker_info() succeeds but a subsequent objcg allocation fails, the free_objcg -> free_shrinker_info() unwind path tears down the already published pn->shrinker_info arrays without shrinker_mutex. The expand_one_shrinker_info() can race with that teardown in the same way, leading to use-after-free or double-free of the old shrinker_info. Fix this by serializing shrinker_info teardown with shrinker_mutex, and by keeping alloc_shrinker_info() error cleanup inside the locked section.
    • Reference: https://git.kernel.org/stable/c/284c267f013e45d8c89d9fb9373105dc8e6c0947
    • Reference: https://git.kernel.org/stable/c/6465ff3ce65131c774a312d450abe10f4b9f3875

Affected operating systems

  • linux

    redhat / enterprise_linux10.0

  • linux

    redhat / enterprise_linux7.0

  • linux

    redhat / enterprise_linux8.0

  • linux

    redhat / enterprise_linux9.0

  • linux

    ubuntu / linux-aws-6.8jammy

  • linux

    ubuntu / linux-azureresolute

  • linux

    ubuntu / linux-azuretrusty

  • linux

    ubuntu / linux-azurexenial

  • linux

    ubuntu / linux-azure-4.15bionic

  • linux

    ubuntu / linux-azure-5.4bionic

  • linux

    ubuntu / linux-azure-fdenoble

  • linux

    ubuntu / linux-azure-fderesolute

  • linux

    ubuntu / linux-azure-fde-6.8jammy

  • linux

    ubuntu / linux-azure-fipsbionic

  • linux

    ubuntu / linux-azure-fipsfocal

  • linux

    ubuntu / linux-azure-fipsnoble

  • linux

    ubuntu / linux-fipsjammy

  • linux

    ubuntu / linux-gcp-7.0noble

  • linux

    ubuntu / linux-gkejammy

  • linux

    ubuntu / linux-nvidia-tegranoble

  • linux

    ubuntu / linux-raspinoble

  • linux

    ubuntu / linux-raspi-realtimenoble

  • linux

    linux / linux_kernel2.6.12

  • linux

    linux / linux_kernel2.6.15

References & sources

Linked CVEs

Show 1392 more CVEs
IDCVE-2026-64418
Linux kernel (GCP) vulnerabilities — CVE-2026-64418 | NEOSEC Intel