Use-After-Free Vulnerability in Linux Kernel's ksmbd Package
Summary
CVE-2025-37777: In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in smb2_lease_break_noti() Move tcp_transport free to ksmbd_conn_free. Affects linux versions 6.1.106-1 – 6.9.9-1. No fix is published. How to fix ↓
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Background
The Linux kernel is the core of the Linux operating system, managing hardware and system resources. It is widely used in various distributions, including Debian. The ksmbd package provides an SMB3 server implementation in the kernel, allowing file sharing over the SMB protocol. This package is crucial for enabling seamless file access across different systems. However, it has recently been identified to have a vulnerability that could lead to serious security issues.
Vulnerability Detail
The vulnerability, identified as CVE-2025-37777, arises from a use-after-free condition in the ksmbd package. Specifically, the issue occurs in the __smb2_lease_break_noti() function, where the tcp_transport is freed while the ksmbd connection is still referenced. This can lead to a situation where the connection is asynchronously processed after it has been freed, potentially allowing an attacker to exploit this condition and execute arbitrary code or crash the system.
How To Fix
No fixed version is published for this vulnerability.
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Workaround
Currently, no specific workarounds have been recommended for this vulnerability. It is advisable to apply the patch as soon as it becomes available to ensure system security.
Conclusion
CVE-2025-37777 is a significant vulnerability in the Linux kernel's ksmbd package that can lead to serious security issues due to a use-after-free condition. Users are strongly advised to update their systems to the latest kernel version to mitigate this risk. Monitoring tools like Vulert can assist in identifying vulnerabilities in your software without requiring code access.
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FAQ
CVE-2025-37777 is a vulnerability in the Linux kernel's ksmbd package that can lead to a use-after-free condition, potentially allowing attackers to exploit the system.
You can use Vulert, which monitors and alerts for open-source vulnerabilities in real-time. By using the Vulert playground, you can check if your application is affected by this vulnerability without any signup.
The risks include potential arbitrary code execution and system crashes, which can compromise the integrity and availability of the affected systems.
Yes, a patch is available. Users should update their Linux kernel to the latest version to mitigate the vulnerability.
While no specific workarounds are available, it is crucial to prioritize applying the patch as soon as possible to protect your system from potential exploitation.
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