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VulnerabilityPublished Updated

CVE-2026-68330: Linux kernel · net: airoha: Fix DMA direction for NPU mailbox buffer

Affects Linux kernelSource GCVE Database

0

Not known to be exploited · CVSS 7.8 High · fixed in 7.0.0-38.38~24.04.4 : patch Linux kernel soon.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 7.0.0-38.38~24.04.4, 7.0.0-38.38, 7.0.0-1014.14 +11
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 10 Aug 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-38.38
Fixed in
  • 7.0.0-38.38
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1014.14
Fixed in
  • 7.0.0-1014.14
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1017.17
Fixed in
  • 7.0.0-1017.17
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1016.16
Fixed in
  • 7.0.0-1016.16
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1014.14
Fixed in
  • 7.0.0-1014.14
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1008.9
Fixed in
  • 7.0.0-1008.9

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

In the Linux kernel, the following vulnerability has been resolved: net: airoha: Fix DMA direction for NPU mailbox buffer airoha_npu_send_msg() always maps the mailbox buffer with DMA_TO_DEVICE, but some callers expect the NPU to write response data back into the same buffer: - airoha_npu_wlan_msg_get() (NPU_OP_GET): NPU writes response into the buffer, then the caller reads it via memcpy() - airoha_npu_ppe_stats_setup() (NPU_OP_SET): NPU writes back npu_stats_addr field in the response On non-cache-coherent architectures like EN7581 (Cortex-A53 without hardware cache coherency for NPU DMA), DMA_TO_DEVICE unmap is a no-op — it does not invalidate the CPU cache. If the NPU-written cache line is still present in the CPU cache when the caller reads the buffer, the CPU observes stale data instead of the NPU response. This is a timing-sensitive bug: small mailbox buffers (~24 bytes) typically fit in a single cache line and may survive in the cache until the caller reads them, producing silent data corruption rather than a crash. The bug is more likely to trigger when the caller reads the response immediately after dma_unmap_single() without intervening cache-evicting operations. Fix by using DMA_BIDIRECTIONAL for both map and unmap, which ensures dma_unmap_single() invalidates the CPU cache on non-coherent systems. The mailbox buffers are small so there is no performance concern.

References

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