CVE-2026-90006
samples/damon/mtier: handle damon_stop() failure
Description
In the Linux kernel, the following vulnerability has been resolved: samples/damon/mtier: handle damon_stop() failure damon_sample_mtier_stop() assumes its damon_stop() call will always successfully stops the two DAMON contexts. Hence it deallocates the two DAMON contexts after the damon_stop() call. However, if a given context is already stopped, damon_stop() fails and returns an error while letting the DAMON contexts that have not yet stopped keep running. This kind of unexpected early DAMON context stops could happen due to memory allocation failures in kdamond_fn(). Because damon_sample_mtier_stop() just deallocates all DAMON contexts with damon_target and damon_region objects that are linked to the contexts, the execution of the unstopped DAMON context (kdamond) ends up using the memory that freed (use-after-free). Fix the issue by separating the damon_stop() to be invoked per context. Note that DAMON_SYSFS also allows multiple DAMON contexts execution. But, it calls damon_stop() for each context one by one. Hence this issue is only in mtier. For the long term, it would be better to refactor damon_stop() to always ensure stopping all contexts regardless of the failures in the middle. Make this fix in the current way, though, to keep it simple and easy to backport. I will do the refactoring later. The issue was discovered [1] by Sashiko.
INFO
Published Date :
Sept. 16, 2026, 11:17 a.m.
Last Modified :
Sept. 16, 2026, 11:17 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-90006
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Apply the patch to handle damon_stop() failure.
- Deallocate DAMON contexts only after successful stop.
- Ensure contexts are stopped before deallocation.
- Avoid use-after-free by proper error handling.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-90006.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-90006 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-90006
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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CVE-2026-90006 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-90006 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 16, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: samples/damon/mtier: handle damon_stop() failure damon_sample_mtier_stop() assumes its damon_stop() call will always successfully stops the two DAMON contexts. Hence it deallocates the two DAMON contexts after the damon_stop() call. However, if a given context is already stopped, damon_stop() fails and returns an error while letting the DAMON contexts that have not yet stopped keep running. This kind of unexpected early DAMON context stops could happen due to memory allocation failures in kdamond_fn(). Because damon_sample_mtier_stop() just deallocates all DAMON contexts with damon_target and damon_region objects that are linked to the contexts, the execution of the unstopped DAMON context (kdamond) ends up using the memory that freed (use-after-free). Fix the issue by separating the damon_stop() to be invoked per context. Note that DAMON_SYSFS also allows multiple DAMON contexts execution. But, it calls damon_stop() for each context one by one. Hence this issue is only in mtier. For the long term, it would be better to refactor damon_stop() to always ensure stopping all contexts regardless of the failures in the middle. Make this fix in the current way, though, to keep it simple and easy to backport. I will do the refactoring later. The issue was discovered [1] by Sashiko. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/90xxx/CVE-2026-90006.json">CVE-2026-90006</a> Added Reference https://git.kernel.org/stable/c/215f9a7e4f1dcfc05ebcdc5c1ad0ea0dcb47bd09 Added Reference https://git.kernel.org/stable/c/3c07c57b894116ae26f01b84c68e68b538ada7ed Added Reference https://git.kernel.org/stable/c/9dc5b6d66fd51b103eff21ed0df3e292f489ebc0