An issue was discovered in the proc_pid_stack function in fs/proc/base.c in the Linux kernel through 4.18.11. It does not ensure that only root may inspect the kernel stack of an arbitrary task, allowing a local attacker to exploit racy stack unwinding and leak kernel task stack contents.
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.