Azure Linux 3.0 セキュリティ更新カーネルCVE-2025-37988]
medium Nessus プラグイン ID 295221
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概要
リモートの Azure Linux ホストに 1 つ以上のセキュリティ更新プログラムがありません。説明
リモートの Azure Linux 3.0 ホストにインストールされているカーネルのバージョンは、テスト済みのバージョンより前です。したがって、CVE-2025-37988 のアドバイザリに記載されている脆弱性の影響を受けます。- Linux カーネルでは、以下の脆弱性が解決されています: fix a couple of races in MNT_TREE_BENEATH handling by do_move_mount() Normally do_lock_mount(path, _) is locking a mountpoint pinned by *path and at the time when matching unlock_mount() unlocks that location it is still pinned by the same thing. Unfortunately, for 'beneath' case it's no longer that simple - the object being locked is not the one *path points to. It's the mountpoint of path->mnt. The thing is, without sufficient locking
->mnt_parent May change under us and none of the locks are held at that point. The rules are * mount_lock stabilizes m->mnt_parent for any mount m. * namespace_sem stabilizes m->mnt_parent, provided that m is mounted. * if either of the above holds and refcount of m is positive, we are guaranteed the same for refcount of m->mnt_parent. namespace_sem nests inside inode_lock(), so do_lock_mount() has to take inode_lock() before grabbing namespace_sem. It does recheck that path->mnt is still mounted in the same place after getting namespace_sem, and it does take care to pin the dentry. It is needed, since otherwise we might end up with racing mount --move (or umount) happening while we were getting locks; in that case dentry would no longer be a mountpoint and could've been evicted on memory pressure along with its inode - not something you want when grabbing lock on that inode. However, pinning a dentry is not enough - the matching mount is also pinned only by the fact that path->mnt is mounted on top it and at that point we are not holding any locks whatsoever, so the same kind of races could end up with all references to that mount gone just as we are about to enter inode_lock(). If that happens, we are left with filesystem being shut down while we are holding a dentry reference on it; results are not pretty. What we need to do is grab both dentry and mount at the same time; that makes inode_lock() safe *and* avoids the problem with fs getting shut down under us. After taking namespace_sem we verify that path->mnt is still mounted (which stabilizes its ->mnt_parent) and check that it's still mounted at the same place. From that point on to the matching namespace_unlock() we are guaranteed that mount/dentry pair we'd grabbed are also pinned by being the mountpoint of path->mnt, so we can quietly drop both the dentry reference (as the current code does) and mnt one - it's OK to do under namespace_sem, since we are not dropping the final refs. That solves the problem on do_lock_mount() side; unlock_mount() also has one, since dentry is guaranteed to stay pinned only until the namespace_unlock(). That's easy to fix - just have inode_unlock() done earlier, while it's still pinned by mp->m_dentry. (CVE-2025-37988)
Nessus はこの問題をテストしておらず、代わりにアプリケーションが自己報告するバージョン番号にのみ依存していることに注意してください。
ソリューション
影響を受けるパッケージを更新してください。参考資料
プラグインの詳細
深刻度: Medium
ID: 295221
ファイル名: azure_linux_CVE-2025-37988.nasl
バージョン: 1.1
タイプ: local
公開日: 2026/1/22
更新日: 2026/1/22
サポートされているセンサー: Nessus
リスク情報
VPR
リスクファクター: Medium
スコア: 4.4
CVSS v2
リスクファクター: Low
基本値: 3.8
現状値: 2.8
ベクトル: CVSS2#AV:L/AC:H/Au:S/C:N/I:N/A:C
CVSS スコアのソース: CVE-2025-37988
CVSS v3
リスクファクター: Medium
基本値: 4.7
現状値: 4.1
ベクトル: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
現状ベクトル: CVSS:3.0/E:U/RL:O/RC:C
脆弱性情報
CPE: p-cpe:/a:microsoft:azure_linux:kernel-debuginfo, p-cpe:/a:microsoft:azure_linux:kernel-devel, p-cpe:/a:microsoft:azure_linux:kernel-drivers-gpu, p-cpe:/a:microsoft:azure_linux:python3-perf, p-cpe:/a:microsoft:azure_linux:kernel-docs, x-cpe:/o:microsoft:azure_linux, p-cpe:/a:microsoft:azure_linux:kernel, p-cpe:/a:microsoft:azure_linux:kernel-drivers-sound, p-cpe:/a:microsoft:azure_linux:bpftool, p-cpe:/a:microsoft:azure_linux:kernel-drivers-intree-amdgpu, p-cpe:/a:microsoft:azure_linux:kernel-drivers-accessibility, p-cpe:/a:microsoft:azure_linux:kernel-tools
必要な KB アイテム: Host/local_checks_enabled, Host/AzureLinux/release, Host/AzureLinux/rpm-list, Host/cpu
エクスプロイトの容易さ: No known exploits are available
パッチ公開日: 2025/7/8
脆弱性公開日: 2025/5/20
参照情報
CVE: CVE-2025-37988