CVE-2026-23355 | ata: libata: cancel pending work after clearing deferred_qc

In the Linux kernel, the following vulnerability has been resolved: ata: libata: cancel pending work after clearing deferred_qc Syzbot reported a WARN_ON() in ata_scsi_deferred_qc_work(), caused by ap->ops->qc_defer() returning non-zero before issuing the deferred qc. ata_scsi_schedule_deferred_qc() is called during each command completion. This function will check if there is a deferred QC, and if ap->ops->qc_defer() returns zero, meaning that it is possible to queue the deferred qc at this time (without being deferred), then it will queue the work which will issue the deferred qc. Once the work get to run, which can potentially be a very long time after the work was scheduled, there is a WARN_ON() if ap->ops->qc_defer() returns non-zero. While we hold the ap->lock both when assigning and clearing deferred_qc, and the work itself holds the ap->lock, the code currently does not cancel the work after clearing the deferred qc. This means that the following scenario can happen: 1) One or several NCQ commands are queued. 2) A non-NCQ command is queued, gets stored in ap->deferred_qc. 3) Last NCQ command gets completed, work is queued to issue the deferred qc. 4) Timeout or error happens, ap->deferred_qc is cleared. The queued work is currently NOT canceled. 5) Port is reset. 6) One or several NCQ commands are queued. 7) A non-NCQ command is queued, gets stored in ap->deferred_qc. 8) Work is finally run. Yet at this time, there is still NCQ commands in flight. The work in 8) really belongs to the non-NCQ command in 2), not to the non-NCQ command in 7). The reason why the work is executed when it is not supposed to, is because it was never canceled when ap->deferred_qc was cleared in 4). Thus, ensure that we always cancel the work after clearing ap->deferred_qc. Another potential fix would have been to let ata_scsi_deferred_qc_work() do nothing if ap->ops->qc_defer() returns non-zero. However, canceling the work when clearing ap->deferred_qc seems slightly more logical, as we hold the ap->lock when clearing ap->deferred_qc, so we know that the work cannot be holding the lock. (The function could be waiting for the lock, but that is okay since it will do nothing if ap->deferred_qc is not set.)

公開: 2026-03-25 最終更新: 2026-06-17 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 ソース: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

総合評価: CVE-2026-23355 は低リスク(22.9/100)。CVSS 深刻度は中。悪用される可能性が高い(EPSS 0.12%、2 パーセンタイル) 推奨対応: 悪用情報と EPSS の推移を監視し、必要に応じて優先度を見直してください。

リスクは変動します。再評価に基づき、本ページの表示内容を更新しています。

CVE-2026-23355 の EPSS(Exploit Prediction Scoring System)スコア

EPSS は日次で悪用されやすさの相対度合いを推定します。パーセンタイルは採点済み CVE の中での相対位置(高いほど相対的に深刻)を示します。

# 日付 旧 EPSS スコア 新 EPSS スコア Δ(新 − 旧)
1 2026-06-15 0.02% 0.12% +0.10%
2 2026-03-25 0.02%

EPSS の全履歴 (全 2 件)

CVE-2026-23355 の CVSS(Common Vulnerability Scoring System)指標

この CVE の CVSS 指標。

ベーススコア バージョン 深刻度 ベクトル 悪用しやすさ 影響 スコアの出典
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H クリックして展開
攻撃ベクター (AV:L)
対象ホスト上でコードを実行できること、または別ユーザーの誤操作・悪意ある操作が前提になる。
攻撃の複雑さ (AC:L)
攻撃者が条件を満たせば、レース条件や珍しい構成に依存せずに再現しやすい。
必要な権限 (PR:L)
一般ユーザー権限があれば足り、管理者(root 相当)は不要。
ユーザーの関与 (UI:N)
メールのリンクを開く、マクロを有効にするなど、被害者の協力がなくても成立しうる。
スコープ (S:U)
影響は脆弱コンポーネントと同一のセキュリティ権限・信頼境界の内側に収まる。
機密性への影響 (C:N)
機微情報の漏えいは想定しにくい。
完全性への影響 (I:N)
改ざん・なりすましによる信頼毀損は軽微か、想定されない。
可用性への影響 (A:H)
長時間のサービス停止、データ損壊による復旧不能に近い状態など、利用者に著しい不便を与えうる。
1.8 3.6 [email protected]

CVE-2026-23355 の弱点分類(列挙)

CVE-2026-23355 の GitHub Security Advisory

GHSA-8672-3h73-hv9p · 深刻度: medium — In the Linux kernel, the following vulnerability has been resolved: ata: libata: cancel pending...

CVE-2026-23355 の OS トラッカー

vendor priority summary link
debian unimportant CVE-2026-23355 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2026-23355
redhat medium https://access.redhat.com/security/cve/CVE-2026-23355
suse medium CVE-2026-23355 severity moderate: SUSE including 26 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 226 product×package rows across 40 product lines (SUSE Linux Enterprise High Availability Extension 15 SP7, SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS, … (40 product lines)): Known Not Affected 226. https://www.suse.com/security/cve/CVE-2026-23355/
ubuntu medium CVE-2026-23355 medium priority: Ubuntu including 157 source packages (linux, linux-allwinner-5.19, …), 1256 status rows across 8 suites (bionic, focal, jammy, noble, questing, trusty, upstream, xenial): DNE 871, ignored 166, not-affected 136, released 83. https://ubuntu.com/security/CVE-2026-23355

CVE-2026-23355 の影響を受けるソフトウェア/構成

ベンダー 製品 バージョン 生の CPE
linux linux_kernel >= 6.18.14, < 6.18.18 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.19.4, < 6.19.7 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 7.0 cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
linux linux_kernel 7.0 cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*

CVE-2026-23355 の参考情報

cvelogic Threat Intelligence