CVE-2021-46928

parisc: Clear stale IIR value on instruction access rights trap

Description

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.

Category

5.5
CVSS
Severity: Medium
CVSS 3.1 •
EPSS 0.01%
Affected: Linux Linux
Affected: Linux Linux
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2021-46928?
CVE-2021-46928 has been scored as a medium severity vulnerability.
How to fix CVE-2021-46928?
To fix CVE-2021-46928, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-46928 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-46928 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-46928?
CVE-2021-46928 affects Linux Linux, Linux Linux.
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