CVE-2026-98059 bpf: Mark sched_process_wait argument as nullable

What is CVE-2026-98059?

CVE-2026-98059 is a medium-severity vulnerability in Linux kernel, 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 sched_process_wait argument as nullable

do_wait() passes wo->wo_pid to the sched_process_wait tracepoint. kernel_wait4() leaves wo_pid NULL for wait4(-1), and kernel_waitid_prepare() does likewise for waitid(P_ALL).

btf_ctx_access() currently types argument 0 as PTR_TO_BTF_ID | PTR_TRUSTED. Without PTR_MAYBE_NULL, the verifier accepts an unchecked dereference. Trusted pointer loads have no fault protection, so a wait for any child can then cause a NULL pointer dereference in JITed BPF code.

Add sched_process_wait to raw_tp_null_args[] with argument 0 marked nullable. The verifier rejects an unchecked dereference while preserving access after the program checks the pointer for NULL.

Weakness: CWE-476

Which versions are affected by CVE-2026-98059?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-98059?

Apply the vendor's patch.

Is CVE-2026-98059 being exploited?

There is no known exploitation of CVE-2026-98059 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 BELL-CVE-2026-98059, DEBIAN-CVE-2026-98059, GHSA-mfrq-h74g-92w2, UBUNTU-CVE-2026-98059.