CVE-2026-80895 Affecting kernel-azure-vdso package, versions <6.12.0-160000.39.1


Severity

Recommended
0.0
medium
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.17% (6th percentile)

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  • Snyk IDSNYK-SLES1600-KERNELAZUREVDSO-21363317
  • published21 Oct 2026
  • disclosed12 Oct 2026

Introduced: 12 Oct 2026

NewCVE-2026-80895  (opens in a new tab)

How to fix?

Upgrade SLES:16.0.0 kernel-azure-vdso to version 6.12.0-160000.39.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-azure-vdso package and not the kernel-azure-vdso package as distributed by SLES. See How to fix? for SLES:16.0.0 relevant fixed versions and status.

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

mshv: Order pt_vp_array publish against irqfd assertion path

mshv_partition_ioctl_create_vp() initialises a VP struct (allocations, mutex_init, init_waitqueue_head, page mappings) and then publishes the pointer into partition->pt_vp_array. Several ISR paths read this array locklessly: the intercept ISR, the two scheduler ISRs, and mshv_try_assert_irq_fast() on the irqfd fast path.

Of these, only mshv_try_assert_irq_fast() can structurally race the publish. It runs from an eventfd waker without holding pt_mutex, and MSHV_IRQFD does not require the target lapic_apic_id (== vp_index) to refer to an existing VP at registration time. A user can therefore register an irqfd targeting a yet-to-be-created VP, then trigger mshv_try_assert_irq_fast() concurrently with MSHV_CREATE_VP for the same index. On weakly-ordered architectures the reader can observe a non-NULL pointer in pt_vp_array before the initialising stores to the VP struct become visible, leading to use of partially-initialised fields (e.g. vp_register_page).

The other ISR readers cannot reach this race: the hypervisor will not generate intercept or scheduler messages for a VP that has never been told to run, and the user can only call MSHV_RUN_VP on the VP fd returned by MSHV_CREATE_VP, which by construction is returned after the publish. Leave those readers as plain loads.

Use smp_store_release() in mshv_partition_ioctl_create_vp() to publish the pointer, and pair it with smp_load_acquire() in mshv_try_assert_irq_fast(). On x86 these compile to plain accesses under TSO; on ARM64 they emit one-instruction acquire/release barriers, acceptable on this fast path.

The destroy-side path (destroy_partition() clearing pt_vp_array[i] to NULL after kfree(vp)) has a separate ordering and lifetime concern that is out of scope here.

CVSS Base Scores

version 3.1