In the Linux kernel, the following vulnerability has been resolved: parisc: Clear stale IIR value on instruction access rights trap When a trap 7 (Instruction access rights) occurs, this means the CPU couldn't execute an instruction due to missing execute permissions on the memory region. In this case it seems the CPU didn't even fetched the instruction from memory and thus did not store it in the cr19 (IIR) register before calling the trap handler. So, the trap handler will find some 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 to understand the various random IIR values in trap 7 dumps.
History

No history.

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2024-02-27T09:43:57.390Z

Updated: 2024-12-19T07:31:59.313Z

Reserved: 2024-02-25T13:45:52.720Z

Link: CVE-2021-46928

cve-icon Vulnrichment

Updated: 2024-08-04T05:17:43.059Z

cve-icon NVD

Status : Modified

Published: 2024-02-27T10:15:07.517

Modified: 2024-11-21T06:34:57.247

Link: CVE-2021-46928

cve-icon Redhat

Severity : Moderate

Publid Date: 2024-02-27T00:00:00Z

Links: CVE-2021-46928 - Bugzilla