CVE-2024-40970 Avoid hw_desc array overrun in dw-axi-dmac
A buffer overrun in the dw-axi-dmac driver can cause a kernel panic, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-40970?
CVE-2024-40970 is a high-severity memory corruption vulnerability in Linux kernel, published on 12 Jul 2024. 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:
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).
Which versions are affected by CVE-2024-40970?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-40970?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2024-40970 being exploited?
There is no known exploitation of CVE-2024-40970 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-40970, DEBIAN-CVE-2024-40970, GHSA-6pg5-rgpc-92pf, ROOT-OS-DEBIAN-11-CVE-2024-40970, UBUNTU-CVE-2024-40970.