bpf: Mark NULL kptr stores precise
Summary
| CVE | CVE-2026-98034 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-25 11:17:32 UTC |
| Updated | 2026-10-19 10:17:57 UTC |
| Description | 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. |
Risk And Classification
EPSS: 0.001550000 probability, percentile 0.039820000 (date 2026-09-27)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 61df10c7799e27807ad5e459eec9d77cddf8bf45 bb667eb575c906f24c707986541a99424c5b07ea git | Not specified |
| CNA | Linux | Linux | affected 61df10c7799e27807ad5e459eec9d77cddf8bf45 86168208737bdd267d92d855d453d1d2f840df19 git | Not specified |
| CNA | Linux | Linux | affected 61df10c7799e27807ad5e459eec9d77cddf8bf45 ecdc5043794c9184aa8e6c814603899479c46b35 git | Not specified |
| CNA | Linux | Linux | affected b5a8069835e5236824a84281592d29f859b33153 git | Not specified |
| CNA | Linux | Linux | affected 5.18.18 5.19 semver | Not specified |
| CNA | Linux | Linux | affected 5.19 | Not specified |
| CNA | Linux | Linux | unaffected 5.19 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.57 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2.7 7.2.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.3 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/ecdc5043794c9184aa8e6c814603899479c46b35 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/86168208737bdd267d92d855d453d1d2f840df19 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/bb667eb575c906f24c707986541a99424c5b07ea | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.