CVE-2025-40139
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-11-12

Last updated on: 2025-11-12

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: smc: Use __sk_dst_get() and dst_dev_rcu() in in smc_clc_prfx_set(). smc_clc_prfx_set() is called during connect() and not under RCU nor RTNL. Using sk_dst_get(sk)->dev could trigger UAF. Let's use __sk_dst_get() and dev_dst_rcu() under rcu_read_lock() after kernel_getsockname(). Note that the returned value of smc_clc_prfx_set() is not used in the caller. While at it, we change the 1st arg of smc_clc_prfx_set[46]_rcu() not to touch dst there.
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Meta Information
Published
2025-11-12
Last Modified
2025-11-12
Generated
2026-06-16
AI Q&A
2025-11-13
EPSS Evaluated
2026-06-14
NVD
CVE-2025-40139
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *
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Exploitability
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CWE ID Description
CWE-UNKNOWN
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Executive Summary

This vulnerability in the Linux kernel involves improper handling of socket destination references in the smc_clc_prfx_set() function. The function was using sk_dst_get(sk)->dev without proper synchronization, which could trigger a use-after-free (UAF) condition. The fix involves using __sk_dst_get() and dev_dst_rcu() under rcu_read_lock() to safely access the destination device, preventing the UAF.

Impact Analysis

The vulnerability could lead to a use-after-free condition in the Linux kernel networking code, potentially causing kernel crashes or allowing an attacker to execute arbitrary code with kernel privileges, leading to system compromise.

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