CVE-2024-56675 bpf: Fix UAF via mismatching bpf_prog/attachment RCU flavors

What is CVE-2024-56675?

CVE-2024-56675 is a high-severity use after free vulnerability in Linux kernel, published on 27 Dec 2024. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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

bpf: Fix UAF via mismatching bpf_prog/attachment RCU flavors

Uprobes always use bpf_prog_run_array_uprobe() under tasks-trace-RCU protection. But it is possible to attach a non-sleepable BPF program to a uprobe, and non-sleepable BPF programs are freed via normal RCU (see __bpf_prog_put_noref()). This leads to UAF of the bpf_prog because a normal RCU grace period does not imply a tasks-trace-RCU grace period.

Fix it by explicitly waiting for a tasks-trace-RCU grace period after removing the attachment of a bpf_prog to a perf_event.

Weakness: CWE-416

Which versions are affected by CVE-2024-56675?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2024-56675?

Apply the vendor's patch.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2024-56675 being exploited?

There is no known exploitation of CVE-2024-56675 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-54733, BELL-CVE-2024-56675, DEBIAN-CVE-2024-56675, GHSA-ppp3-73jm-5rm6, UBUNTU-CVE-2024-56675.