CVE-2026-52971

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.