U.S. flag   An official website of the United States government
Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock (Dot gov) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2021-46990 Detail

Description

In the Linux kernel, the following vulnerability has been resolved: powerpc/64s: Fix crashes when toggling entry flush barrier The entry flush mitigation can be enabled/disabled at runtime via a debugfs file (entry_flush), which causes the kernel to patch itself to enable/disable the relevant mitigations. However depending on which mitigation we're using, it may not be safe to do that patching while other CPUs are active. For example the following crash: sleeper[15639]: segfault (11) at c000000000004c20 nip c000000000004c20 lr c000000000004c20 Shows that we returned to userspace with a corrupted LR that points into the kernel, due to executing the partially patched call to the fallback entry flush (ie. we missed the LR restore). Fix it by doing the patching under stop machine. The CPUs that aren't doing the patching will be spinning in the core of the stop machine logic. That is currently sufficient for our purposes, because none of the patching we do is to that code or anywhere in the vicinity.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

By selecting these links, you will be leaving NIST webspace. We have provided these links to other web sites because they may have information that would be of interest to you. No inferences should be drawn on account of other sites being referenced, or not, from this page. There may be other web sites that are more appropriate for your purpose. NIST does not necessarily endorse the views expressed, or concur with the facts presented on these sites. Further, NIST does not endorse any commercial products that may be mentioned on these sites. Please address comments about this page to [email protected].

URL Source(s) Tag(s)
https://git.kernel.org/stable/c/0b4eb172cc12dc102cd0ad013e53ee4463db9508 CVE, kernel.org Patch 
https://git.kernel.org/stable/c/0c25a7bb697f2e6ee65b6d63782f675bf129511a CVE, kernel.org Patch 
https://git.kernel.org/stable/c/2db22ba4e0e103f00e0512e0ecce36ac78c644f8 CVE, kernel.org Patch 
https://git.kernel.org/stable/c/5bc00fdda1e934c557351a9c751a205293e68cbf CVE, kernel.org Patch 
https://git.kernel.org/stable/c/8382b15864e5014261b4f36c2aa89723612ee058 CVE, kernel.org Patch 
https://git.kernel.org/stable/c/aec86b052df6541cc97c5fca44e5934cbea4963b CVE, kernel.org Patch 
https://git.kernel.org/stable/c/d2e3590ca39ccfd8a5a46d8c7f095cb6c7b9ae92 CVE, kernel.org Patch 
https://git.kernel.org/stable/c/dd0d6117052faace5440db20fc37175efe921c7d CVE, kernel.org Patch 
https://git.kernel.org/stable/c/ee4b7aab93c2631c3bb0753023c5dda592bb666b CVE, kernel.org Patch 

Weakness Enumeration

CWE-ID CWE Name Source
NVD-CWE-noinfo Insufficient Information cwe source acceptance level NIST  

Known Affected Software Configurations Switch to CPE 2.2

CPEs loading, please wait.

Denotes Vulnerable Software
Are we missing a CPE here? Please let us know.

Change History

6 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2021-46990
NVD Published Date:
02/28/2024
NVD Last Modified:
12/26/2024
Source:
kernel.org