CVE-2026-52971 net: ena: PHC: Fix potential use-after-free in get_timestamp
A race condition in the Linux kernel ENA driver allows a use-after-free, potentially leading to system crashes or arbitrary code execution.
- 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-2026-52971?
CVE-2026-52971 is a high-severity use after free vulnerability in Linux kernel, published on 24 Jun 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:
net: ena: PHC: Fix potential use-after-free in get_timestamp
Move the phc->active check and resp pointer assignment to after acquiring the spinlock. Previously, phc->active was checked without holding the lock, and resp was cached from ena_dev->phc.virt_addr before the lock was acquired.
If ena_com_phc_destroy() runs between the lockless active check and the lock acquisition, it sets active=false, releases the lock, frees the DMA memory, and sets virt_addr=NULL. The get_timestamp path would then read a NULL virt_addr and dereference it.
With both the active check and the pointer read under the lock, destroy cannot free the memory while get_timestamp is using it.
Which versions are affected by CVE-2026-52971?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-52971?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-52971 being exploited?
There is no known exploitation of CVE-2026-52971 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-52971, DEBIAN-CVE-2026-52971, GHSA-pffq-9wr4-6hjx, UBUNTU-CVE-2026-52971.