CVE-2026-52971net: ena: PHC: Fix potential use-after-free in get_timestamp

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.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/95e8ae9af2a61b4e72f5c585bf4c7d8aaf2a2c98
• https://git.kernel.org/stable/c/ca9ed40f28949353911dcb524ff8fff2f3409c97
• https://git.kernel.org/stable/c/e42c755582f0960e684298762f0ab927b3778376