CVE-2026-23083
Unknown Unknown - Not Provided
Use-After-Free in Linux Kernel FOU Component Due to Invalid IPPROTO

Publication date: 2026-02-04

Last updated on: 2026-03-18

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: fou: Don't allow 0 for FOU_ATTR_IPPROTO. fou_udp_recv() has the same problem mentioned in the previous patch. If FOU_ATTR_IPPROTO is set to 0, skb is not freed by fou_udp_recv() nor "resubmit"-ted in ip_protocol_deliver_rcu(). Let's forbid 0 for FOU_ATTR_IPPROTO.
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Meta Information
Published
2026-02-04
Last Modified
2026-03-18
Generated
2026-06-16
AI Q&A
2026-02-04
EPSS Evaluated
2026-06-15
NVD
CVE-2026-23083
Affected Vendors & Products
Showing 12 associated CPEs
Vendor Product Version / Range
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel From 5.11 (inc) to 5.15.199 (exc)
linux linux_kernel From 5.16 (inc) to 6.1.162 (exc)
linux linux_kernel From 6.2 (inc) to 6.6.122 (exc)
linux linux_kernel From 6.7 (inc) to 6.12.68 (exc)
linux linux_kernel From 6.13 (inc) to 6.18.8 (exc)
linux linux_kernel 6.19
linux linux_kernel From 3.18 (inc) to 5.10.249 (exc)
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Exploitability
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CWE ID Description
CWE-UNKNOWN
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Executive Summary

This vulnerability exists in the Linux kernel's handling of the FOU (Foo Over UDP) protocol attribute FOU_ATTR_IPPROTO. Specifically, if the FOU_ATTR_IPPROTO is set to 0, the function fou_udp_recv() does not properly free the associated socket buffer (skb) nor resubmit it in ip_protocol_deliver_rcu(). This improper handling can lead to resource management issues. The fix involves forbidding the value 0 for FOU_ATTR_IPPROTO to prevent this problem.

Impact Analysis

If FOU_ATTR_IPPROTO is set to 0, the Linux kernel's fou_udp_recv() function fails to free the socket buffer or resubmit it properly. This can lead to resource leaks or unexpected behavior in network packet processing, potentially causing system instability or degraded performance.

Compliance Impact

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