You are viewing this page in an unauthorized frame window.
This is a potential security issue, you are being redirected to
https://nvd.nist.gov
An official website of the United States government
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock () or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.
This CVE record has recently been published to the CVE List and has been included within the NVD dataset.
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.
Metrics
NVD enrichment efforts reference publicly available information to associate
vector strings. CVSS information contributed by other sources is also
displayed.
By selecting these links, you will be leaving NIST webspace.
We have provided these links to other web sites because they
may have information that would be of interest to you. No
inferences should be drawn on account of other sites being
referenced, or not, from this page. There may be other web
sites that are more appropriate for your purpose. NIST does
not necessarily endorse the views expressed, or concur with
the facts presented on these sites. Further, NIST does not
endorse any commercial products that may be mentioned on
these sites. Please address comments about this page to [email protected].
New CVE Received from kernel.org8/10/2026 9:20:23 AM
Action
Type
Old Value
New Value
Added
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.
) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.
