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.

CVE-2022-49164 Detail

Description

In the Linux kernel, the following vulnerability has been resolved: powerpc/tm: Fix more userspace r13 corruption Commit cf13435b730a ("powerpc/tm: Fix userspace r13 corruption") fixes a problem in treclaim where a SLB miss can occur on the thread_struct->ckpt_regs while SCRATCH0 is live with the saved user r13 value, clobbering it with the kernel r13 and ultimately resulting in kernel r13 being stored in ckpt_regs. There is an equivalent problem in trechkpt where the user r13 value is loaded into r13 from chkpt_regs to be recheckpointed, but a SLB miss could occur on ckpt_regs accesses after that, which will result in r13 being clobbered with a kernel value and that will get recheckpointed and then restored to user registers. The same memory page is accessed right before this critical window where a SLB miss could cause corruption, so hitting the bug requires the SLB entry be removed within a small window of instructions, which is possible if a SLB related MCE hits there. PAPR also permits the hypervisor to discard this SLB entry (because slb_shadow->persistent is only set to SLB_NUM_BOLTED) although it's not known whether any implementations would do this (KVM does not). So this is an extremely unlikely bug, only found by inspection. Fix this by also storing user r13 in a temporary location on the kernel stack and don't change the r13 register from kernel r13 until the RI=0 critical section that does not fault. The SCRATCH0 change is not strictly part of the fix, it's only used in the RI=0 section so it does not have the same problem as the previous SCRATCH0 bug.


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 nvd@nist.gov.

Hyperlink Resource
https://git.kernel.org/stable/c/5dce84f475d13b773a1a4c823581cab25044d86a
https://git.kernel.org/stable/c/73d8082c90f17dfba57cad4ca94db5cae323f1b1
https://git.kernel.org/stable/c/9d71165d3934e607070c4e48458c0cf161b1baea

Weakness Enumeration

CWE-ID CWE Name Source

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2022-49164
NVD Published Date:
02/26/2025
NVD Last Modified:
02/26/2025
Source:
kernel.org