CVE-2021-46969: In the Linux kernel, the following vulnerability has been resolved: bus: mhi: core: Fix invalid error returning in mhi_queue mhi_queue returns an er...

Description

In the Linux kernel, the following vulnerability has been resolved: bus: mhi: core: Fix invalid error returning in mhi_queue mhi_queue returns an error when the doorbell is not accessible in the current state. This can happen when the device is in non M0 state, like M3, and needs to be waken-up prior ringing the DB. This case is managed earlier by triggering an asynchronous M3 exit via controller resume/suspend callbacks, that in turn will cause M0 transition and DB update. So, since it's not an error but just delaying of doorbell update, there is no reason to return an error. This also fixes a use after free error for skb case, indeed a caller queuing skb will try to free the skb if the queueing fails, but in that case queueing has been done.

Metrics

CVSS 3.1

7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.22%

12.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-416

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	>= 5.12, < 5.12.3

References

Timeline

Published: Feb 27, 2024
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2021-46969?

In the Linux kernel, the following vulnerability has been resolved: bus: mhi: core: Fix invalid error returning in mhi_queue mhi_queue returns an error when the doorbell is not accessible in the current state. This can happen when the device is in non M0 state, like M3, and needs to be waken-up prior ringing the DB. This case is managed earlier by triggering an asynchronous M3 exit via controller resume/suspend callbacks, that in turn will cause M0 transition and DB update. So, since it's not an error but just delaying of doorbell update, there is no reason to return an error. This also fixes a use after free error for skb case, indeed a caller queuing skb will try to free the skb if the queueing fails, but in that case queueing has been done.

How severe is CVE-2021-46969?

CVE-2021-46969 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.22% probability of exploitation in the next 30 days.

How do I fix CVE-2021-46969?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.