Intel

CVE-2026-64416

Linux kernel (GCP) vulnerabilities

mediumEPSS 0.1%

Description

In the Linux kernel, the following vulnerability has been resolved: mm: swap_cgroup: fix NULL deref in lookup_swap_cgroup_id on swapless host lookup_swap_cgroup_id() passes swap_cgroup_ctrl[type].map to __swap_cgroup_id_lookup() without checking that the type was ever registered via swap_cgroup_swapon(). On a swapless host every ctrl->map is NULL, so __swap_cgroup_id_lookup() dereferences NULL + a scaled swp_offset(). Since commit bea67dcc5eea ("mm: attempt to batch free swap entries for zap_pte_range()"), zap_pte_range() -> swap_pte_batch() calls lookup_swap_cgroup_id() on any non-present, non-none PTE that decodes as a real swap entry, without first validating it against swap_info[]. A single PTE corrupted into a type-0 swap entry takes the host down at process exit. We hit this in production on a swapless 6.12.58 host: ~1s of "get_swap_device: Bad swap file entry 3f800204222bb" (do_swap_page() being correctly defensive about the same entry) followed by BUG: unable to handle page fault for address: 000003f800204220 RIP: 0010:lookup_swap_cgroup_id+0x2b/0x60 Call Trace: swap_pte_batch+0xbf/0x230 zap_pte_range+0x4c8/0x780 unmap_page_range+0x190/0x3e0 exit_mmap+0xd9/0x3c0 do_exit+0x20c/0x4b0 syzbot has reported the identical stack. The source of the PTE corruption is a separate bug; this change makes the teardown path as robust as the fault path already is. Every other caller of lookup_swap_cgroup_id() is downstream of a get_swap_device() that has already validated the entry, so the new branch is cold.

Source: UBUNTU_USNUBUNTU_USNUBUNTU_USNBSIBSI_CSAFDEBIAN_DSANVDCVELISTV5

Metrics

Severity
medium
Priority score
231.31
KEV status
—
Exploit maturity
no public PoC known
XIEM Effective CVSS
5.5
Source: nvd-v3
CVSS v3
5.5
CVSS v4
—
EPSS percentile
2.3 %
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: swap_cgroup: fix NULL deref in lookup_swap_cgroup_id on swapless host lookup_swap_cgroup_id() passes swap_cgroup_ctrl[type].map to __swap_cgroup_id_lookup() without checking that the type was ever registered via swap_cgroup_swapon(). On a swapless host every ctrl->map is NULL, so __swap_cgroup_id_lookup() dereferences NULL + a scaled swp_offset(). Since commit bea67dcc5eea ("mm: attempt to batch free swap entries for zap_pte_range()"), zap_pte_range() -> swap_pte_batch() calls lookup_swap_cgroup_id() on any non-present, non-none PTE that decodes as a real swap entry, without first validating it against swap_info[]. A single PTE corrupted into a type-0 swap entry takes the host down at process exit. We hit this in production on a swapless 6.12.58 host: ~1s of "get_swap_device: Bad swap file entry 3f800204222bb" (do_swap_page() being correctly defensive about the same entry) followed by BUG: unable to handle page fault for address: 000003f800204220 RIP: 0010:lookup_swap_cgroup_id+0x2b/0x60 Call Trace: swap_pte_batch+0xbf/0x230 zap_pte_range+0x4c8/0x780 unmap_page_range+0x190/0x3e0 exit_mmap+0xd9/0x3c0 do_exit+0x20c/0x4b0 syzbot has reported the identical stack. The source of the PTE corruption is a separate bug; this change makes the teardown path as robust as the fault path already is. Every other caller of lookup_swap_cgroup_id() is downstream of a get_swap_device() that has already validated the entry, so the new branch is cold.
    • Reference: https://git.kernel.org/stable/c/63b02a9409cb5180398491b093e48bcb5315f5fb
    • Reference: https://git.kernel.org/stable/c/6a4196d19f477524d2f92adca90fc1fbe9a0420a

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-2026-64416
Linux kernel (GCP) vulnerabilities — CVE-2026-64416 | NEOSEC Intel