CVE-2025-40139 Details
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.
A use-after-free vulnerability has been identified in the Linux kernel's handling of SMC CLC prefixes. This issue arises in the 'smc_clc_prfx_set' function, which is called during the connection process without proper synchronization, potentially leading to the use of a freed memory reference. The vulnerability has been addressed by modifying the function to use '__sk_dst_get()' and 'dst_dev_rcu()' under a read-side RCU lock, ensuring safe access to network device information. The change prevents the use-after-free condition by correctly managing the lifecycle of the referenced data.
Users can upgrade to the patched version of the Linux kernel available in the Linux Kernel Stable Tree.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Nov 12, 2025References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://git.kernel.org/stable/c/0736993bfe5c7a9c744ae3fac62d769dfdae54e1 | kernel.org | Source CodeVendor |
| https://git.kernel.org/stable/c/5a2fccc4b32c13ddde3676f9e15e1a9baa7d6fde | kernel.org | |
| https://git.kernel.org/stable/c/80d1fd39f4e37d836655e9f7ffccaf78925049bf | kernel.org | |
| https://git.kernel.org/stable/c/935d783e5de9b64587f3adb25641dd8385e64ddb | kernel.org | Source CodeVendor |
| https://git.kernel.org/stable/c/956c57daba55cf9ed25d9f2512883b8a1a927599 | kernel.org |
Weakness Enumeration
No weakness enumeration is available for this CVE.
Affected Products
| Product | Versions |
|---|---|
| Linux kernel | All versions |
CPE
Remediation
| |
Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Sep 2, 2026 | CVE Modified | kernel.org |
| Jul 30, 2026 | CVE Modified | kernel.org |
| Jun 17, 2026 | CVE Modified | kernel.org |
| Nov 12, 2025 | New CVE Received | kernel.org |