CVE-2022-50219 bpf: Fix KASAN use-after-free Read in compute_effective_progs
A use-after-free vulnerability in the Linux kernel's BPF subsystem allows attackers to potentially execute arbitrary code or escalate privileges.
- 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-2022-50219?
CVE-2022-50219 is a high-severity use after free vulnerability in Linux kernel, published on 18 Jun 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 KASAN use-after-free Read in compute_effective_progs
Syzbot found a Use After Free bug in compute_effective_progs(). The reproducer creates a number of BPF links, and causes a fault injected alloc to fail, while calling bpf_link_detach on them. Link detach triggers the link to be freed by bpf_link_free(), which calls __cgroup_bpf_detach() and update_effective_progs(). If the memory allocation in this function fails, the function restores the pointer to the bpf_cgroup_link on the cgroup list, but the memory gets freed just after it returns. After this, every subsequent call to update_effective_progs() causes this already deallocated pointer to be dereferenced in prog_list_length(), and triggers KASAN UAF error.
To fix this issue don't preserve the pointer to the prog or link in the list, but remove it and replace it with a dummy prog without shrinking the table. The subsequent call to __cgroup_bpf_detach() or __cgroup_bpf_detach() will correct it.
Weakness: CWE-416
Which versions are affected by CVE-2022-50219?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-50219?
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-2022-50219 being exploited?
There is no known exploitation of CVE-2022-50219 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-50219, GHSA-f8rq-3pf9-vf74, UBUNTU-CVE-2022-50219.