CVE-2021-46928
What it is
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.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 5.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Weakness
- CWE-755
- Record status
- Modified
Affected
- Linux Kernel < 5.10.90
- Linux Kernel < 5.15.13
Attack profile CVSS 3.1 · 5.5
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2021-46928.md and follow it. Check whether this project is affected by CVE-2021-46928. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/484730e5862f6b872dca13840bed40fd7c60fa26
- https://git.kernel.org/stable/c/d01e9ce1af6116f812491d3d3873d204f10ae0b8
- https://git.kernel.org/stable/c/e96373f0a5f484bc1e193f9951dcb3adf24bf3f7
- https://git.kernel.org/stable/c/484730e5862f6b872dca13840bed40fd7c60fa26
- https://git.kernel.org/stable/c/d01e9ce1af6116f812491d3d3873d204f10ae0b8
- https://git.kernel.org/stable/c/e96373f0a5f484bc1e193f9951dcb3adf24bf3f7
References
- https://git.kernel.org/stable/c/484730e5862f6b872dca13840bed40fd7c60fa26
- https://git.kernel.org/stable/c/d01e9ce1af6116f812491d3d3873d204f10ae0b8
- https://git.kernel.org/stable/c/e96373f0a5f484bc1e193f9951dcb3adf24bf3f7
- https://git.kernel.org/stable/c/484730e5862f6b872dca13840bed40fd7c60fa26
- https://git.kernel.org/stable/c/d01e9ce1af6116f812491d3d3873d204f10ae0b8
- https://git.kernel.org/stable/c/e96373f0a5f484bc1e193f9951dcb3adf24bf3f7