CVE-2026-43358
RCU Locking Issue in Linux Kernel Btrfs
Publication date: 2026-05-08
Last updated on: 2026-05-08
Assigner: kernel.org
Description
Description
CVSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | * |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
Attack-Flow Graph
AI Powered Q&A
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability is related to a missing RCU unlock in the Linux kernel's btrfs subsystem, specifically in the try_release_subpage_extent_buffer() function. Detection would typically require analyzing the kernel source code or using static analysis tools like the Clang thread-safety analyzer that originally detected the issue.
There are no specific network or system commands provided to detect this vulnerability directly.
Can you explain this vulnerability to me?
This vulnerability is in the Linux kernel's btrfs filesystem code. It involves a missing RCU (Read-Copy-Update) unlock call in the error path of the function try_release_subpage_extent_buffer(). Specifically, the function calls rcu_read_lock() before a loop but fails to call rcu_read_unlock() if an error occurs and the loop exits early. This can lead to improper synchronization and potential issues in kernel memory management.
How can this vulnerability impact me? :
The impact of this vulnerability could include kernel instability or memory corruption due to improper handling of RCU locks. This might lead to system crashes or unpredictable behavior when using the btrfs filesystem on affected Linux kernels.
What immediate steps should I take to mitigate this vulnerability?
The vulnerability has been resolved by adding the missing RCU unlock in the error path of the try_release_subpage_extent_buffer() function in the Linux kernel.
Immediate mitigation steps would include updating your Linux kernel to a version that includes this fix.