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.
git.kernel.org/linus/5bb60ea611db1e04814426ed4bd1c95d1487678e (5.16-rc3)
git.kernel.org/stable/c/5bb60ea611db1e04814426ed4bd1c95d1487678e
git.kernel.org/stable/c/c4e3ff8b8b1d54f0c755670174c453b06e17114b
git.kernel.org/stable/c/dfe906da9a1abebdebe8b15bb3e66a2578f6c4c7
launchpad.net/bugs/cve/CVE-2021-47567
nvd.nist.gov/vuln/detail/CVE-2021-47567
security-tracker.debian.org/tracker/CVE-2021-47567
www.cve.org/CVERecord?id=CVE-2021-47567