CVE-2026-74401
dlm: fix add msg handle in send_queue ordered
Description
In the Linux kernel, the following vulnerability has been resolved: dlm: fix add msg handle in send_queue ordered In a benchmark scenario triggering a lot of requests that triggers a lot of DLM messages on the network it can be that the mh->seq is not ordered according the oldest seq number. This ordering is required by dlm_receive_ack as "before(mh->seq, seq)" will stop to check for older sequence numbers that are ordered in the tail of "node->send_queue". The side effects of not having it correct ordered regarding "before(mh->seq, seq)" are refcounting issues and use-after free. I only was able to reproduce this issue in a experimental DLM branch and a user space DLM benchmark that uses io_uring. After changing this I don't experienced any refcounting with the sending buffer issues anymore.
INFO
Published Date :
Aug. 15, 2026, 6:22 a.m.
Last Modified :
Aug. 15, 2026, 6:22 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-74401
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
- Update the Linux kernel to the latest version.
- Apply the provided patch for DLM ordering.
- Ensure message sequence numbers are correctly ordered.
- Test for refcounting and buffer issues.
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-2026-74401.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-74401 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-2026-74401
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).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-74401 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-74401 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
Aug. 15, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '489d8e559c6596eb08e16447d9830bc39afbe54e', 'lessThan': 'ae9e534e502a0f48c12baf83608c5de0ff0eab11', 'versionType': 'git'}, {'status': 'affected', 'version': '489d8e559c6596eb08e16447d9830bc39afbe54e', 'lessThan': '6369619f1b665f12d8c99cc6ff733c64eb08b22e', 'versionType': 'git'}, {'status': 'affected', 'version': '489d8e559c6596eb08e16447d9830bc39afbe54e', 'lessThan': '712714f818d83373847874ab0f8e426be79296cf', 'versionType': 'git'}, {'status': 'affected', 'version': '489d8e559c6596eb08e16447d9830bc39afbe54e', 'lessThan': '4d45250b1d22960f86d83245be188b16e456218b', 'versionType': 'git'}, {'status': 'affected', 'version': '489d8e559c6596eb08e16447d9830bc39afbe54e', 'lessThan': 'd2248cb70c070f8f04762872772e155b59016f17', 'versionType': 'git'}], 'programFiles': ['fs/dlm/midcomms.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.14'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.14', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.97', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.40', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.5', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['fs/dlm/midcomms.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: dlm: fix add msg handle in send_queue ordered In a benchmark scenario triggering a lot of requests that triggers a lot of DLM messages on the network it can be that the mh->seq is not ordered according the oldest seq number. This ordering is required by dlm_receive_ack as "before(mh->seq, seq)" will stop to check for older sequence numbers that are ordered in the tail of "node->send_queue". The side effects of not having it correct ordered regarding "before(mh->seq, seq)" are refcounting issues and use-after free. I only was able to reproduce this issue in a experimental DLM branch and a user space DLM benchmark that uses io_uring. After changing this I don't experienced any refcounting with the sending buffer issues anymore. Added Reference https://git.kernel.org/stable/c/4d45250b1d22960f86d83245be188b16e456218b Added Reference https://git.kernel.org/stable/c/6369619f1b665f12d8c99cc6ff733c64eb08b22e Added Reference https://git.kernel.org/stable/c/712714f818d83373847874ab0f8e426be79296cf Added Reference https://git.kernel.org/stable/c/ae9e534e502a0f48c12baf83608c5de0ff0eab11 Added Reference https://git.kernel.org/stable/c/d2248cb70c070f8f04762872772e155b59016f17