CVE-2021-47567 Information

Description

In the Linux kernel the following vulnerability has been resolved:

powerpc/32: Fix hardlockup on vmap stack overflow

Since the commit c118c7303ad5 (\powerpc/32: Fix vmap stack - Do not activate MMU before reading task struct) a vmap stack overflow results in a hard lockup. This is because emergency_ctx is still addressed with its virtual address allthough data MMU is not active anymore at that time.

Fix it by using a physical address instead.

Reference

https://git.kernel.org/stable/c/dfe906da9a1abebdebe8b15bb3e66a2578f6c4c7 https://git.kernel.org/stable/c/c4e3ff8b8b1d54f0c755670174c453b06e17114b https://git.kernel.org/stable/c/5bb60ea611db1e04814426ed4bd1c95d1487678e