CVE-2026-31434
Memory Leak in Linux Kernel btrfs Sub-Group space_info Component
Publication date: 2026-04-22
Last updated on: 2026-04-22
Assigner: kernel.org
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | kernel | to 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (exc) |
| linux | kernel | * |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
Attack-Flow Graph
AI Powered Q&A
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The provided information does not specify any impact of this vulnerability on compliance with common standards and regulations such as GDPR or HIPAA.
Can you explain this vulnerability to me?
This vulnerability is a memory leak in the Linux kernel's btrfs filesystem code. Specifically, when creating sub-groups of space_info, the kernel allocates objects and initializes them with kobject_init_and_add(). However, when these objects are freed, the proper removal function btrfs_sysfs_remove_space_info() is not called. Instead, a simple free operation is done, which skips calling kobject_put() and causes the associated kobject name objects to leak memory.
The leak can be detected by running specific kernel memory leak detection tests (kmemleak) and is triggered during certain btrfs operations involving space_info sub-groups.
How can this vulnerability impact me? :
This vulnerability causes a memory leak in the Linux kernel when using the btrfs filesystem. Over time, this leak can lead to increased memory consumption, potentially degrading system performance or causing resource exhaustion.
While it does not directly lead to code execution or privilege escalation, the leak could affect system stability, especially on systems with heavy btrfs usage or limited memory.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability can be detected by running the blktests test case zbd/009 on kernels built with CONFIG_DEBUG_KMEMLEAK enabled.
The kmemleak feature will report unreferenced objects indicating the memory leak, showing details such as the process name, pid, and a backtrace.
Specifically, the error message will show unreferenced kobject name objects leaked during the btrfs sub-group space_info operations.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, ensure that the kernel code calls btrfs_sysfs_remove_space_info() instead of kfree() when freeing elements of space_info->sub_group[].
This change prevents the memory leak by properly releasing the kobject name objects.