Vulnerability in Linux kernel (CVE-2026-90342)
Summary
Vulnerability in Linux kernel (CVE-2026-90342). 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: Fix mmap_lock deadlock on arena lock failure
Reported by the Sashiko AI review.
arena_vm_fault() returns VM_FAULT_RETRY when it can't take
arena->spinlock, but it never took mmap_lock. The fault path assumes a
VM_FAULT_RETRY handler already dropped mmap_lock and re-takes it on the
retry, so mmap_lock gets taken twice and can deadlock:
do_user_addr_fault()
{
fault = handle_mm_fault(...); // calls arena_vm_fault()
if (fault & VM_FAULT_RETRY)
goto retry; // re-locks mmap_lock
mmap_read_unlock(mm);
}
Return VM_FAULT_SIGBUS instead, for two reasons:
-
We could keep VM_FAULT_RETRY, but then we'd have to drop the fault
lock first and cap the retry ourselves, the way __folio_lock_or_retry()
does. -
A failed raw_res_spin_lock_irqsave() already means a possible deadlock
was detected, so retrying just hits the same lock again.
So returning VM_FAULT_RETRY here is overkill.
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-2026-90342 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-2026-90342" on the vendor's site.
CVE-2026-90342 (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