Improper input validation in Linux kernel - CVE-2026-90359

Vulnerability details

The vulnerability allows a local privileged user to corrupt function return values.

The vulnerability exists due to improper validation of return value size in BPF return-reading trampolines when attaching a BPF program to a function with a return value larger than 8 bytes. A local privileged user can attach a BPF program using a supported return-reading attach type to corrupt function return values.

Affected attach types include fexit, fmod_ret, fsession, their applicable multi variants, and struct_ops.

Affected software

How to mitigate CVE-2026-90359

External References

• https://git.kernel.org/stable/c/c48796aa6c392cde93946e5d5a9a1f1b1cf72feb
• https://git.kernel.org/stable/c/d36ac53fc83baf843c51b7afd6d2471f36b713d8

Related Security Bulletins

• Improper input validation in Linux kernel bpf