Vulnerability in Linux kernel (CVE-2026-90359)
Summary
Vulnerability in Linux kernel (CVE-2026-90359). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
bpf: Reject >8 byte return values on return-reading trampoline paths
btf_distill_func_proto() builds the function model used for the
fentry/fexit/fmod_ret/fsession trampolines and struct_ops. It has
accepted a 16-byte __int128 return value since the trampoline was
introduced: __get_type_size() returns the integer's type size, and the
return-type check only rejected ret < 0.
But the BPF trampoline preserves only 8 bytes of the return value (RAX on
x86, i.e. R0). For an attach type that reads the target's return value the
second half (RDX / R3) is neither saved nor restored, so a program
attached to a function returning a 16-byte value corrupts the value seen
by the real caller and itself observes only half of it. struct_ops
trampolines have the same limitation.
This affects the attach types that read the target's return value: fexit,
fmod_ret and fsession (plus the _multi variants of fexit and fsession),
and struct_ops. fentry/fentry_multi run before the target returns and are
unaffected.
Reject a >8 byte return value for these attach types in
bpf_check_attach_target() and bpf_check_attach_btf_id_multi(), and for
struct_ops in bpf_struct_ops_desc_init().
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-90359 has been found in Linux kernel.
Risk of unauthorized operations or information disclosure.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-90359" on the vendor's site.
CVE-2026-90359 (Linux kernel)
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (unclassified) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。
-
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- web git.kernel.org
- web git.kernel.org
- web nvd.nist.gov
- web github.com
- web git.kernel.org