Race Condition Vulnerability in Linux Kernel's SMB Client - CVE-2025-39825
Summary
CVE-2025-39825: In the Linux kernel, the following vulnerability has been resolved: smb: client: fix race with concurrent opens in rename(2) Besides sending the rename request to the server, the rename process also involves closing any... Affects linux versions 5.10.103-1 – 6.9.9-1. No fix is published. How to fix ↓
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Background
The Linux kernel is the core component of the Linux operating system, responsible for managing hardware resources and providing essential services to applications. It supports a wide range of functionalities, including process management, memory management, and file system operations. This vulnerability affects the SMB (Server Message Block) client within the Linux kernel, which is used for network file sharing and communication with Windows systems. The vulnerability arises from a race condition during the rename operation, potentially leading to unauthorized access or data corruption.
Vulnerability Detail
In the Linux kernel, a race condition exists in the SMB client during the rename operation. When a rename request is sent to the server, the process involves closing deferred closes, waiting for outstanding I/O to complete, and marking existing open handles as deleted. This sequence increases the risk of concurrent opens on the target file, which can lead to unexpected behavior or data integrity issues. The vulnerability is identified as CVE-2025-39825 and has been resolved in later versions of the Linux package.
How To Fix
No fixed version is published for this vulnerability.
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Workaround
Currently, no specific workaround has been mentioned for this vulnerability. It is recommended to apply the patch as soon as it is available to mitigate the risk.
Conclusion
CVE-2025-39825 represents a significant vulnerability in the Linux kernel's SMB client, stemming from a race condition during file rename operations. Users are advised to update their systems to the patched version 6.16.5-1 to mitigate potential risks. Regular monitoring for vulnerabilities using tools like Vulert can help maintain system security.
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FAQ
CVE-2025-39825 is a vulnerability in the Linux kernel's SMB client that allows for a race condition during file rename operations, potentially leading to unauthorized access or data corruption.
If exploited, this vulnerability can allow concurrent opens on a target file, which may compromise data integrity and security.
You should update your Linux package to the patched version 6.16.5-1 to protect your system from this vulnerability.
Currently, there is no specific workaround available. The best course of action is to apply the patch as soon as it is released.
You can use Vulert, which monitors and alerts in real-time for open-source vulnerabilities in your software using a manifest file like package-lock.json. You can check if your application is affected by this vulnerability using the Vulert playground without any signup.
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