CVE-2026-72474 dmaengine: dma-axi-dmac: use DMA pool to manange DMA descriptor
A bug in the Linux kernel AXI DMA driver causes a kernel crash when freeing memory in interrupt context, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-72474?
CVE-2026-72474 is a denial of service vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-72474?
How do I fix CVE-2026-72474?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-72474 being exploited?
There is no known exploitation of CVE-2026-72474 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-72474, DEBIAN-CVE-2026-72474, GHSA-x3wp-gmcj-4wm5, UBUNTU-CVE-2026-72474.