Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: fou: Fix use-after-free in fou_create() fou_create() publishes struct fou through sk_user_data before adding the new FOU port to the per-netns list. If fou_add_to_port_list() fails, the error path frees fou while it is still reachable through sk_user_data. A concurrent receive can then dereference the freed object in fou_from_sock(). This ordering issue was previously noted in the linked discussion. The failure is reachable when local port 0 is requested. Each socket binds to a different ephemeral port, but fou_cfg_cmp() compares the requested port 0 and reports -EALREADY once an entry already exists. Release the tunnel socket before freeing fou so sk_user_data is cleared first, and defer reclamation with kfree_rcu() to protect concurrent RCU readers. This matches the lifetime handling in fou_release().
CVSS Score
HIGH
References
- https://git.kernel.org/stable/c/a28d8903bfe76089ea4bbdbff9976965f9ef8107
- https://git.kernel.org/stable/c/b14361aca6350ff7907b0e9903c7b94dc7d5d4a0
FAQ
What is CVE-2026-74496?
CVE-2026-74496 is a vulnerability with a CVSS score of 7.8 (HIGH). In the Linux kernel, the following vulnerability has been resolved: fou: Fix use-after-free in fou_create() fou_create() publishes struct fou through sk_user_data before adding the new FOU port to t...
How severe is CVE-2026-74496?
CVE-2026-74496 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-74496?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.