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Review reviewHigh

CVE-2025-40274

Linux

In the Linux kernel, the following vulnerability has been resolved: KVM: guest_memfd: Remove bindings on memslot deletion when gmem is dying When unbinding a memslot from a guest_memfd instance, remove the bindings even if the guest_memfd file is dying, i.e. even if its file refcount has gone to zero. If the memslot is freed before the file is fully released, nullifying the memslot side of the binding in kvm_gmem_release() will write to freed memory, as detected by syzbot+KASAN: ================================================================== BUG: KASAN: slab-use-after-free in kvm_gmem_re...

CVSS
7.8
EPSS
0.13%
3.30% percentile
CISA KEV
Not listed
Published
2025.12.07
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.13%
Technical severityCVSS 7.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: KVM: guest_memfd: Remove bindings on memslot deletion when gmem is dying When unbinding a memslot from a guest_memfd instance, remove the bindings even if the guest_memfd file is dying, i.e. even if its file refcount has gone to zero. If the memslot is freed before the file is fully released, nullifying the memslot side of the binding in kvm_gmem_release() will write to freed memory, as detected by syzbot+KASAN: ================================================================== BUG: KASAN: slab-use-after-free in kvm_gmem_re...

Affected product and versions

Product
Linux
Affected versions
>= a7800aa80ea4d5356b8474c2302812e9d4926fa6 < a8ac2bd0f98e1a230f1eb3260fa552bf2ef1753b, >= a7800aa80ea4d5356b8474c2302812e9d4926fa6 < 393893693a523e053f84d69320d090b93503f79f, >= a7800aa80ea4d5356b8474c2302812e9d4926fa6 < ae431059e75d36170a5ae6b44cc4d06d43613215, >= 6.8
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
Not available