bpf: Mark NULL kptr stores precise
Key facts
- Attack vector
- —
- Privileges required
- —
- User interaction
- —
- Attack complexity
- —
- Impact type
- —
- Confidentiality · integrity · availability
- —
- Fix status
- Partial Red Hat: 4 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: bpf: Mark NULL kptr stores precise check_map_kptr_access() permits a scalar store into an untrusted kptr field only when the register is known to contain zero. Unlike other verifier checks whose outcome depends on a scalar value, it does not mark that register precise. A state checkpoint reached with an imprecise zero can therefore prune a second path that reaches the store with an arbitrary nonzero scalar. The program can write attacker-controlled bits into the kptr field and load them back as a PTR_TO_BTF_ID. Call mark_chain_precision() before accepting a known-zero register. This forces state equivalence to compare its scalar range and makes the verifier visit and reject a path carrying a nonzero value.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.19
- Fix · CNA Linux (Linux) Fixed in 6.6.160, 6.12.114, 6.18.57, 7.2.7, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet |
Not affected: 4 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat OpenShift Container Platform 4
Timeline
- 2026-10-02 Threatist record created from CVE-2026-98034
- 2026-10-03 Alias added: GHSA-r89f-4x69-4v8p
- 2026-10-16 Fix available: Linux/[email protected], Linux/Linux@bb667eb575c906f24c707986541a99424c5b07ea · CNA
- 2026-10-16 1 new reference · CNA
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-21 Fix available: Linux/[email protected], Linux/[email protected], Linux/Linux@86a3171c90bfc35a54e9d83cd197ca0d72d2f4e4 +1 · CNA
- 2026-10-21 2 new references · CNA
- 2026-10-30 Affected versions changed · Red Hat
References
Other 5
- https://git.kernel.org/stable/c/86a3171c90bfc35a54e9d83cd197ca0d72d2f4e4
- https://git.kernel.org/stable/c/b8b98d3d37908402ff63515fa4d7574235436ea8
- https://git.kernel.org/stable/c/bb667eb575c906f24c707986541a99424c5b07ea
- https://git.kernel.org/stable/c/86168208737bdd267d92d855d453d1d2f840df19
- https://git.kernel.org/stable/c/ecdc5043794c9184aa8e6c814603899479c46b35
More Linux vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
Sources
- CVE-2026-98034 · CVE Program
- CVE-2026-98034 · NVD
- FIRST EPSS
- GHSA-r89f-4x69-4v8p · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98034 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences