CVE-2025-40149: linux kernel Use-After-Free — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: tls: Use __sk_dst_get() and dst_dev_rcu() in get_netdev_for_sock(). get_netdev_for_sock() is called during setsockopt(), so not under RCU. Using sk_dst_get(sk)->dev could trigger UAF. Let's use __sk_dst_get() and dst_dev_rcu(). Note that the only ->ndo_sk_get_lower_dev() user is bond_sk_get_lower_dev(), which uses RCU.

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CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness Type (CWE)

CWE-416 Use After Free

Affected Products

Vendor	Product	Versions
linux	linux_kernel	4.18 — 5.15.199
linux	linux_kernel	5.16 — 6.1.161
linux	linux_kernel	6.2 — 6.6.121
linux	linux_kernel	6.7 — 6.12.66
linux	linux_kernel	6.13 — 6.17.3

References

Advisories & Patches

https://git.kernel.org/stable/c/13159c7125636371543a82cb7bbae00ab36730cc https://git.kernel.org/stable/c/2b1bef126bbb8d0da51491357559126d567c1dee https://git.kernel.org/stable/c/c65f27b9c3be2269918e1cbad6d8884741f835c5 https://git.kernel.org/stable/c/e37ca0092ddace60833790b4ad7a390408fb1be9 https://git.kernel.org/stable/c/f09cd209359a23f88d4f3fa3d2379d057027e53c https://git.kernel.org/stable/c/feb474ddbf26b51f462ae2e60a12013bdcfc5407

Frequently Asked Questions

What is CVE-2025-40149? +

In the Linux kernel, the following vulnerability has been resolved: tls: Use __sk_dst_get() and dst_dev_rcu() in get_netdev_for_sock(). get_netdev_for_sock() is called during setsockopt(), so not under RCU. Using sk_dst_get(sk)->dev could trigger UAF. Let's use __sk_dst_get() and dst_dev_rcu(). Note that the only ->ndo_sk_get_lower_dev() user is bond_sk_get_lower_dev(), which uses RCU. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2025-40149? +

CVE-2025-40149 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-40149? +

CVE-2025-40149 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-40149? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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