Description
In the Linux kernel, the following vulnerability has been resolved:
dmaengine: dma-axi-dmac: use DMA pool to manange DMA descriptor
For architectures like Microblaze or arm64 (where this IP is used),
DMA_DIRECT_REMAP is set which means that dma_alloc_coherent() might
remap (and hence vmalloc()) some memory. This became visible in a design
where dma_direct_use_pool() is not possible.
With the above, when calling dma_free_coherent(), vunmap() would be
called from softirq context and thus leading to a BUG().
To fix it, use a dma pool that is allocated in
.device_alloc_chan_resources() and allocate blocks from it. The key
point is that now dma_pool_free() is used in axi_dmac_free_desc() to
free the blocks and that just frees the blocks from the pool in the
sense they can be used again. In other words, no actual call to
dma_free_coherent() happens. That only happens when destroying the pool
in axi_dmac_free_chan_resources() which does not happen in any interrupt
context.
dmaengine: dma-axi-dmac: use DMA pool to manange DMA descriptor
For architectures like Microblaze or arm64 (where this IP is used),
DMA_DIRECT_REMAP is set which means that dma_alloc_coherent() might
remap (and hence vmalloc()) some memory. This became visible in a design
where dma_direct_use_pool() is not possible.
With the above, when calling dma_free_coherent(), vunmap() would be
called from softirq context and thus leading to a BUG().
To fix it, use a dma pool that is allocated in
.device_alloc_chan_resources() and allocate blocks from it. The key
point is that now dma_pool_free() is used in axi_dmac_free_desc() to
free the blocks and that just frees the blocks from the pool in the
sense they can be used again. In other words, no actual call to
dma_free_coherent() happens. That only happens when destroying the pool
in axi_dmac_free_chan_resources() which does not happen in any interrupt
context.
Published:
2026-08-15
Score:
n/a
EPSS:
< 1% Very Low
KEV:
No
Impact:
n/a
Action:
n/a
Analysis
No analysis available yet.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
|||||||||||||||||||||
| Linux | Linux | affected |
|
No data.
No data.
No data available yet.
Remediation
No remediation available yet.
Tracking
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Advisories
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References
History
Sat, 15 Aug 2026 06:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: dmaengine: dma-axi-dmac: use DMA pool to manange DMA descriptor For architectures like Microblaze or arm64 (where this IP is used), DMA_DIRECT_REMAP is set which means that dma_alloc_coherent() might remap (and hence vmalloc()) some memory. This became visible in a design where dma_direct_use_pool() is not possible. With the above, when calling dma_free_coherent(), vunmap() would be called from softirq context and thus leading to a BUG(). To fix it, use a dma pool that is allocated in .device_alloc_chan_resources() and allocate blocks from it. The key point is that now dma_pool_free() is used in axi_dmac_free_desc() to free the blocks and that just frees the blocks from the pool in the sense they can be used again. In other words, no actual call to dma_free_coherent() happens. That only happens when destroying the pool in axi_dmac_free_chan_resources() which does not happen in any interrupt context. | |
| Title | dmaengine: dma-axi-dmac: use DMA pool to manange DMA descriptor | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-08-15T05:57:15.073Z
Reserved: 2026-08-09T03:40:39.934Z
Link: CVE-2026-72474
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-08-15T06:22:21.563
Modified: 2026-08-15T06:22:21.563
Link: CVE-2026-72474
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.