Linux Kernel up to 6.5.4 /mnt nr_hw_queues memory leak

Summaryinfo

A vulnerability labeled as critical has been found in Linux Kernel up to 6.5.4. This issue affects the function nr_hw_queues of the file /mnt. Such manipulation leads to memory leak. This vulnerability is documented as CVE-2023-54227. There is not any exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.5.4 and classified as critical. Affected by this issue is the function nr_hw_queues of the file /mnt. The manipulation with an unknown input leads to a memory leak vulnerability. Using CWE to declare the problem leads to CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. Impacted is availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: blk-mq: fix tags leak when shrink nr_hw_queues Although we don't need to realloc set->tags[] when shrink nr_hw_queues, we need to free them. Or these tags will be leaked. How to reproduce: 1. mount -t configfs configfs /mnt 2. modprobe null_blk nr_devices=0 submit_queues=8 3. mkdir /mnt/nullb/nullb0 4. echo 1 > /mnt/nullb/nullb0/power 5. echo 4 > /mnt/nullb/nullb0/submit_queues 6. rmdir /mnt/nullb/nullb0 In step 4, will alloc 9 tags (8 submit queues and 1 poll queue), then in step 5, new_nr_hw_queues = 5 (4 submit queues and 1 poll queue). At last in step 6, only these 5 tags are freed, the other 4 tags leaked.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2023-54227 since 12/30/2025. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 319348 (EulerOS Virtualization 2.12.1 : kernel (EulerOS-SA-2026-2077)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.5.5 eliminates this vulnerability. Applying the patch c0ef7493e68b8896806a2f598fcffbaa97333405/e1dd7bc93029024af5688253b0c05181d6e01f8e is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (319348) and CERT Bund (WID-SEC-2025-2941). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Debian Linux
• Amazon Linux 2
• IBM Power Hardware Management Console
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• Open Source Linux Kernel
• RESF Rocky Linux
• IBM DataPower Gateway

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.5.0
• 6.5.1
• 6.5.2
• 6.5.3
• 6.5.4

License

• open-source

Website

• Vendor: https://www.kernel.org/

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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