CVE-2025-68742 bpf: Fix invalid prog->stats access when update_effective_progs fails

Not scored Published 24 Dec 2025 Updated 15 Oct 2026

A local attacker can trigger a kernel crash via invalid memory access in BPF stats handling when program updates fail.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Local or same network only
Victim action needed: Not needed
Fix: Available

What is CVE-2025-68742?

CVE-2025-68742 is a vulnerability in Linux, published on 24 Dec 2025. 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 invalid prog->stats access when update_effective_progs fails

Syzkaller triggers an invalid memory access issue following fault injection in update_effective_progs. The issue can be described as follows:

__cgroup_bpf_detach update_effective_progs compute_effective_progs bpf_prog_array_alloc <-- fault inject purge_effective_progs /* change to dummy_bpf_prog */ array->items[index] = &dummy_bpf_prog.prog

---softirq start--- __do_softirq ... __cgroup_bpf_run_filter_skb __bpf_prog_run_save_cb bpf_prog_run stats = this_cpu_ptr(prog->stats) /* invalid memory access */ flags = u64_stats_update_begin_irqsave(&stats->syncp) ---softirq end---

static_branch_dec(&cgroup_bpf_enabled_key[atype])

The reason is that fault injection caused update_effective_progs to fail and then changed the original prog into dummy_bpf_prog.prog in purge_effective_progs. Then a softirq came, and accessing the members of dummy_bpf_prog.prog in the softirq triggers invalid mem access.

To fix it, skip updating stats when stats is NULL.

Which versions are affected by CVE-2025-68742?

How do I fix CVE-2025-68742?

Apply the vendor's patch.

Is CVE-2025-68742 being exploited?

There is no known exploitation of CVE-2025-68742 in the wild and no public exploit code.

Sources

Also known as AZL-73108, BELL-CVE-2025-68742, DEBIAN-CVE-2025-68742, GHSA-jvhg-r77c-vccf, ROOT-OS-DEBIAN-11-CVE-2025-68742, ROOT-OS-DEBIAN-12-CVE-2025-68742 and 3 more.