Vulnerability in Linux kernel (CVE-2026-98818)
Summary
Vulnerability in Linux kernel (CVE-2026-98818). 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/slab: do not wake up kswapd in __kfree_rcu_sheaf()
Since kfree_rcu() can be called under pi_lock (a raw spinlock in the
scheduler), kfree_rcu() itself should never allocate memory with
__GFP_KSWAPD_RECLAIM as waking up kswapd ends up acquiring pi_lock,
which leads to a deadlock.
Reproducing the issue even intentionally was not straightforward.
The set_cpus_allowed_force() path that is called under pi_lock is
exercised very rarely, and competing tasks that allocate memory will
most likely wake kswapd up.
Therefore the existence of the deadlock was verified with a modified
kernel that has a lockdep map for waking up kswapd:
======================================================
WARNING: possible circular locking dependency detected
7.2.0-rc1-slab-for-next+ #10 Not tainted
git/6660 is trying to acquire lock:
ffff8e524533c550 (&p->pi_lock){-.-.}-{2:2}, at: _raw_spin_lock_irqsave+0x12/0x20
but task is already holding lock:
ffff8e57bffff1a0 (&pgdat->kswapd_wait){....}-{3:3}, at: _raw_spin_lock_irqsave+0x12/0x20
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&pgdat->kswapd_wait){....}-{3:3}:
__lock_acquire+0x5a4/0xc50
lock_acquire.part.0+0xb7/0x240
lock_acquire+0x70/0x170
__raw_spin_lock_irqsave+0x44/0x80
_raw_spin_lock_irqsave+…
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-2026-98818 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-2026-98818" on the vendor's site.
CVE-2026-98818 (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。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-98818 linux Fixed in: 7.2.10-1
References
- web git.kernel.org
- web git.kernel.org
- web nvd.nist.gov
- web github.com