CVE-2021-46928

    Dashboard / Vulnerabilities / CVE-2021-46928

    CVE-2021-46928

    Published: 27 Feb 2024Last Modified: 14 Mar 2026

    Summary:

    Details: 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.

    References: https://git.kernel.org/stable/c/484730e5862f6b872dca13840bed40fd7c60fa26, https://git.kernel.org/stable/c/d01e9ce1af6116f812491d3d3873d204f10ae0b8, https://git.kernel.org/stable/c/e96373f0a5f484bc1e193f9951dcb3adf24bf3f7

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: N/A

    Events:

    Introduced- None
    Fixed -None

    Affected versions

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    CVE-2021-46928 | CVE-DB