Vulnerability in Linux kernel (CVE-2026-98226)
Summary
Vulnerability in Linux kernel (CVE-2026-98226). 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:
mm, swap: fix SWAP_USAGE_OFFLIST_BIT collision with real usage count
SWAP_USAGE_OFFLIST_BIT is embedded in the si->inuse_pages usage counter,
and is meant to sit above any value that counter can reach. However, it
is defined from BITS_PER_TYPE(atomic_t), so it is bit 30. On a system
with 4 KiB pages the flag collides with the usage count once that count
reaches 4 TiB.
swap_usage_in_pages() masks bit 30 out, so whenever the real count has
that bit set, every caller of it reads 4 TiB low:
-
/proc/swaps understates Used by 4 TiB.
-
A raw count of exactly 2^30 masks to zero, so try_to_unuse() takes its
"if (!swap_usage_in_pages(si)) goto success;" early exit and swapoff
tears the device down while pages are still swapped out. Nothing in
the rest of swapoff aborts the teardown, so those pages are lost.
Independently of swapoff, the collision also corrupts the counter and the
plist. On a device in normal use, a free that leaves bit 30 set in the
count makes swap_usage_sub() see the flag where there is only count, and
call add_to_avail_list(). It clears the bit with
fetch_and(~SWAP_USAGE_OFFLIST_BIT), leaving the stored count 4 TiB below
the real one, and calls plist_add() on a device that is already listed,
tripping the WARN_ON(!plist_node_empty(node)) in plist_add() and linking
the node a second time.
Change the definition of SWAP_USAGE_OFFLIST_BIT to be based on
atomic_long_t instead. Note that…
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-2026-98226 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-2026-98226" on the vendor's site.
CVE-2026-98226 (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。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Ubuntu UBUNTU-CVE-2026-98226 linux-hwe-edge
References
- advisory nvd.nist.gov
- advisory github.com
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web github.com