cve/2021/CVE-2021-46928.md

CVE-2021-46928

Description

In the Linux kernel, the following vulnerability has been resolved:parisc: Clear stale IIR value on instruction access rights trapWhen a trap 7 (Instruction access rights) occurs, this means the CPUcouldn't execute an instruction due to missing execute permissions onthe memory region. In this case it seems the CPU didn't even fetchedthe instruction from memory and thus did not store it in the cr19 (IIR)register before calling the trap handler. So, the trap handler will findsome random old stale value in cr19.This patch simply overwrites the stale IIR value with a constant magic"bad food" value (0xbaadf00d), in the hope people don't start to try tounderstand the various random IIR values in trap 7 dumps.

POC

Reference

No PoCs from references.

Github

• https://github.com/fkie-cad/nvd-json-data-feeds