fsverity: Fix bpf_get_fsverity_digest() dynptr assumptions (CVE-2026-74590) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-74590

fsverity: Fix bpf_get_fsverity_digest() dynptr assumptions

Answer in brief

CVE-2026-74590 records a Unknown severity vulnerability in fsverity: Fix bpf_get_fsverity_digest() dynptr assumptions. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 22, 2026Updated Aug 22, 2026Source checked Aug 22, 2026First seen by HOL Aug 22, 2026Material review Aug 22, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=67814c00de3161181cddd06c77aeaf86ac4cc584 <1344b632cb5043e32939a84568125719111c5af3 \|\| >=67814c00de3161181cddd06c77aeaf86ac4cc584 <2a5cfcad1d56e26d645b7887b0ed24c371851525 \|\| >=67814c00de3161181cddd06c77aeaf86ac4cc584 <5bd63cad9df4328a184c409fbdad4f17944bcdb8 \|\| >=67814c00de3161181cddd06c77aeaf86ac4cc584 <3e8ec7c0387273329374f5c7bd61f5f38af71fe1	1344b632cb5043e32939a84568125719111c5af3, 2a5cfcad1d56e26d645b7887b0ed24c371851525, 5bd63cad9df4328a184c409fbdad4f17944bcdb8, 3e8ec7c0387273329374f5c7bd61f5f38af71fe1
Linux/Linuxgeneric	6.8	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 1344b632cb5043e32939a84568125719111c5af3 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 22, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 22, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 22, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: fsverity: Fix bpf_get_fsverity_digest() dynptr assumptions The BPF verifier and the dynptr abstraction ensure that the memory space referenced by a dynptr remains valid. They do not, however, provide any guarantee that the contents of the memory are stable. kfuncs are expected to remain memory-safe even if concurrent modifications occur. bpf_get_fsverity_digest() didn't follow that: it could crash if arg->digest_size was concurrently modified. Fix that by using the known-good value hash_alg->digest_size instead. Also widen 'dynptr_sz' and 'out_digest_sz' to u64 to match the return type of __bpf_dynptr_size(). It doesn't appear that it can actually be more than INT_MAX currently (since __bpf_dynptr_data_rw() excludes file-based pointers), but the correct type might as well be used.

Quoted source text, attributed separately from HOL analysis.