SB2025082091 - Race condition in Linux kernel smb server
Published: August 20, 2025 Updated: September 25, 2025
Security Bulletin ID
SB2025082091
Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Code execution
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Race condition (CVE-ID: CVE-2025-38561)
The vulnerability allows a remote user to execute arbitrary code.
The vulnerability exists due to a race condition within the smb2_sess_setup() function in fs/smb/server/smb2pdu.c when handling the Preauth_HashValue field. A remote user can execute arbitrary code in the context of the kernel.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/44a3059c4c8cc635a1fb2afd692d0730ca1ba4b6
- https://git.kernel.org/stable/c/6613887da1d18dd2ecfd6c6148a873c4d903ebdc
- https://git.kernel.org/stable/c/7d7c0c5304c88bcbd7a85e9bcd61d27e998ba5fc
- https://git.kernel.org/stable/c/b69fd87076daa66f3d186bd421a7b0ee0cb45829
- https://git.kernel.org/stable/c/edeecc7871e8fc0878d53ce286c75040a0e38f6c
- https://git.kernel.org/stable/c/fbf5c0845ed15122a770bca9be1d9b60b470d3aa
- https://www.zerodayinitiative.com/advisories/ZDI-25-916/