CVE-2026-90313

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

bpf, cgroup: Fix invalid storage access after __cgroup_bpf_attach failed

A potential invalid storage access issue can occur after replacing a

cgroup bpf prog.

This occurs in the following scenario:

1. prog1 with storage is attached to a cgroup in multi-attach mode.

2. prog1 is replaced with prog2 using BPF_F_REPLACE in multi-attach

mode, but fails midway (e.g. in bpf_trampoline_link_cgroup_shim or

update_effective_progs).

3. A new prog3 is attached to the cgroup in multi-attach mode.

The reason is that __cgroup_bpf_attach overwrites pl->storage with the

new storage prior to attachment completion. When attachment fails

midway, the cleanup path calls bpf_cgroup_storages_free(new_storage) to

free the newly allocated storage, but fails to restore pl->storage back

to old_storage.

Consequently, the still-active prog1 holds invalid or dangling storage

pointers, leading to an invalid memory access when prog1 execute

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References