CVE-2026-98045 bpf: Mark faultable stack helpers as sleepable
A local attacker can cause a kernel denial of service by triggering sleepable operations in non-sleepable BPF contexts.
- 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-2026-98045?
CVE-2026-98045 is a denial of service vulnerability in Linux, published on 25 Sep 2026. 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: Mark faultable stack helpers as sleepable
The faultable variants of bpf_get_stack() and bpf_get_task_stack() pass may_fault=true into the common stack collection code. Resolving user-space build IDs may then call build_id_parse_file() and block on filesystem reads.
Neither helper prototype sets might_sleep. Since prototype selection uses the sleepability of the whole program, the verifier can still allow these helpers from a non-sleepable region within that program, such as an explicit RCU or preemption-disabled region. The task-stack helper can also be called from a non-sleepable timer callback of a sleepable program.
Mark both faultable prototypes as sleepable. The existing helper context check then rejects these calls while continuing to allow them in genuinely sleepable contexts.
Which versions are affected by CVE-2026-98045?
How do I fix CVE-2026-98045?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-98045 being exploited?
There is no known exploitation of CVE-2026-98045 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-98045, DEBIAN-CVE-2026-98045, GHSA-x3f6-2q7c-8rc9, UBUNTU-CVE-2026-98045.