CVE-2026-68330

What the bug is

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.

Where it lives

The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.

drivers/net/ethernet/airoha/airoha_npu.c

What this is

AIROHA ETHERNET DRIVERMAINTAINERS section matched on drivers/net/ethernet/airoha/ · linux-arm-kernel@lists.infradead.org · Maintained

Check it on the machine

grep -wE 'CONFIG_ETHERNET|CONFIG_NET_AIROHA_NPU|CONFIG_NET_VENDOR_AIROHA' /boot/config-$(uname -r)

Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.

Show whether Debian builds this, per release

Debian does not build this code in 2 releases. The build rule could not be established for 2 releases, so nothing is claimed about those.

• bookworm, trixie?
• forky, sidn

?

not established - no Makefile entry for the affected file

n

not enabled on any flavour - this release does not build the code

Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.

Build switches

CONFIG_ETHERNET, CONFIG_NET_AIROHA_NPU, CONFIG_NET_VENDOR_AIROHA

Reads as

all on means the file is compiled; any one off means it is not.

From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages

Signals

Published

2026-08-10 (2 months ago)source

CVSS

7.8 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsource recompute it

Attack vector

local (AV:L)source

EPSS

0.16%, higher than 4.9% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

unimportantsource

Subsystem

drivers/net

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
6.16	6.18.42	76fc5604308a
6.16	7.1.6	4c4d866a64f3
6.16	7.2	6f884eb87a79