Linux Kernel up to 6.1.46/6.4.11 cifs smb2_reconnect_server use after free

Summaryinfo

A vulnerability identified as critical has been detected in Linux Kernel up to 6.1.46/6.4.11. This affects the function smb2_reconnect_server of the component cifs. The manipulation leads to use after free. This vulnerability is uniquely identified as CVE-2023-53794. No exploit exists. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.1.46/6.4.11 and classified as critical. This issue affects the function smb2_reconnect_server of the component cifs. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: cifs: fix session state check in reconnect to avoid use-after-free issue Don't collect exiting session in smb2_reconnect_server(), because it will be released soon. Note that the exiting session will stay in server->smb_ses_list until it complete the cifs_free_ipc() and logoff() and then delete itself from the list.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2023-53794 since 12/09/2025. The exploitation is known to be easy. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 03/29/2026).

The vulnerability scanner Nessus provides a plugin with the ID 302439 (EulerOS 2.0 SP12 : kernel (EulerOS-SA-2026-1366)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.1.47 or 6.4.12 eliminates this vulnerability. Applying the patch 7e4f5c3f01fb0e51ca438e43262d858daf9a0a76/759ffc164d95a32c09528766d74d9b4fb054e8f4/99f280700b4cc02d5f141b8d15f8e9fad0418f65 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 (302439) and CERT Bund (WID-SEC-2025-2765). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• Open Source Linux Kernel
• RESF Rocky Linux

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.1.0
• 6.1.1
• 6.1.2
• 6.1.3
• 6.1.4
• 6.1.5
• 6.1.6
• 6.1.7
• 6.1.8
• 6.1.9
• 6.1.10
• 6.1.11
• 6.1.12
• 6.1.13
• 6.1.14
• 6.1.15
• 6.1.16
• 6.1.17
• 6.1.18
• 6.1.19
• 6.1.20
• 6.1.21
• 6.1.22
• 6.1.23
• 6.1.24
• 6.1.25
• 6.1.26
• 6.1.27
• 6.1.28
• 6.1.29
• 6.1.30
• 6.1.31
• 6.1.32
• 6.1.33
• 6.1.34
• 6.1.35
• 6.1.36
• 6.1.37
• 6.1.38
• 6.1.39
• 6.1.40
• 6.1.41
• 6.1.42
• 6.1.43
• 6.1.44
• 6.1.45
• 6.1.46
• 6.4.0
• 6.4.1
• 6.4.2
• 6.4.3
• 6.4.4
• 6.4.5
• 6.4.6
• 6.4.7
• 6.4.8
• 6.4.9
• 6.4.10
• 6.4.11

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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