CVE-2025-38538 dmaengine: nbpfaxi: Fix memory corruption in probe()
A memory corruption vulnerability in the Linux kernel's nbpfaxi DMA driver allows attackers to potentially execute arbitrary code or escalate privileges.
- 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-2025-38538?
CVE-2025-38538 is a high-severity memory corruption vulnerability in Debian Debian Linux, published on 16 Aug 2025. 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: nbpfaxi: Fix memory corruption in probe()
The nbpf->chan[] array is allocated earlier in the nbpf_probe() function and it has "num_channels" elements. These three loops iterate one element farther than they should and corrupt memory.
The changes to the second loop are more involved. In this case, we're copying data from the irqbuf[] array into the nbpf->chan[] array. If the data in irqbuf[i] is the error IRQ then we skip it, so the iterators are not in sync. I added a check to ensure that we don't go beyond the end of the irqbuf[] array. I'm pretty sure this can't happen, but it seemed harmless to add a check.
On the other hand, after the loop has ended there is a check to ensure that the "chan" iterator is where we expect it to be. In the original code we went one element beyond the end of the array so the iterator wasn't in the correct place and it would always return -EINVAL. However, now it will always be in the correct place. I deleted the check since we know the result.
Weakness: CWE-787
Which versions are affected by CVE-2025-38538?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2025-38538?
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-2025-38538 being exploited?
There is no known exploitation of CVE-2025-38538 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as BELL-CVE-2025-38538, DEBIAN-CVE-2025-38538, GHSA-646r-2h84-3p3v, ROOT-OS-DEBIAN-11-CVE-2025-38538, ROOT-OS-DEBIAN-12-CVE-2025-38538, ROOT-OS-DEBIAN-13-CVE-2025-38538 and 3 more.