CVE-2025-40170
Published Nov 12, 2025
Modified Apr 15, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: net: use dst_dev_rcu() in sk_setup_caps() Use RCU to protect accesses to dst->dev from sk_setup_caps() and sk_dst_gso_max_size(). Also use dst_dev_rcu() in ip6_dst_mtu_maybe_forward(), and ip_dst_mtu_maybe_forward(). ip4_dst_hoplimit() can use dst_dev_net_rcu().
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References
Frequently Asked Questions
What is CVE-2025-40170? +
In the Linux kernel, the following vulnerability has been resolved:
net: use dst_dev_rcu() in sk_setup_caps()
Use RCU to protect accesses to dst->dev from sk_setup_caps()
and sk_dst_gso_max_size().
Also use dst_dev_rcu() in ip6_dst_mtu_maybe_forward(),
and ip_dst_mtu_maybe_forward().
ip4_dst_hoplimit() can use dst_dev_net_rcu().
How do I check if I'm vulnerable to CVE-2025-40170? +
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.