What’s Vulnerable › Vulnerabilities

CVE-2024-27394: tcp: Fix Use-After-Free in tcp_ao_connect_init

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2024-05-14 · updated 2026-08-04
• Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: tcp: Fix Use-After-Free in tcp_ao_connect_init Since call_rcu, which is called in the hlist_for_each_entry_rcu traversal of tcp_ao_connect_init, is not part of the RCU read critical section, it is possible that the RCU grace period will pass during the traversal and the key will be free. To prevent this, it should be changed to hlist_for_each_entry_safe.

Affected products

• Linux kernel: from 6.7 before 6.8.9; 6.9-rc1, 6.9-rc2, 6.9-rc3, 6.9-rc4, 6.9-rc5 — fixed in 6.8.9

How to fix

Upgrade to a fixed version: Linux kernel 6.8.9. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/80e679b352c3ce5158f3f778cfb77eb767e586fb
• https://git.kernel.org/stable/c/ca4fb6c6764b3f75b4f5aa81db1536291897ff7f
• https://git.kernel.org/stable/c/80e679b352c3ce5158f3f778cfb77eb767e586fb
• https://git.kernel.org/stable/c/ca4fb6c6764b3f75b4f5aa81db1536291897ff7f

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