# CVE-2024-40970: Avoid hw\_desc array overrun in dw-axi-dmac

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-07-12 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 5.12

## Description

In the Linux kernel, the following vulnerability has been resolved: Avoid hw_desc array overrun in dw-axi-dmac I have a use case where nr_buffers = 3 and in which each descriptor is composed by 3 segments, resulting in the DMA channel descs_allocated to be 9. Since axi_desc_put() handles the hw_desc considering the descs_allocated, this scenario would result in a kernel panic (hw_desc array will be overrun). To fix this, the proposal is to add a new member to the axi_dma_desc structure, where we keep the number of allocated hw_descs (axi_desc_alloc()) and use it in axi_desc_put() to handle the hw_desc array correctly. Additionally I propose to remove the axi_chan_start_first_queued() call after completing the transfer, since it was identified that unbalance can occur (started descriptors can be interrupted and transfer ignored due to DMA channel not being enabled).

## What to do

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## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/7c3bb96a20cd8db3b8824b2ff08b6cde4505c7e5
- https://git.kernel.org/stable/c/dd42570018f5962c10f215ad9c21274ed5d3541e
- https://git.kernel.org/stable/c/e151ae1ee065cf4b8ce4394ddb9d9c8df6370c66
- https://git.kernel.org/stable/c/9004784e8d68bcd1ac1376407ba296fa28f04dbe
- https://git.kernel.org/stable/c/333e11bf47fa8d477db90e2900b1ed3c9ae9b697

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Page: https://cve.now/CVE-2024-40970
JSON: https://cve.now/api/v1/entries/CVE-2024-40970
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