Azure Linux 3.0 セキュリティ更新カーネルCVE-2024-47741]
high Nessus プラグイン ID 295716
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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-2024-47741 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: btrfs: fix race setting file private on concurrent lseek using same fd When doing concurrent lseek(2) system calls against the same file descriptor, using multiple threads belonging to the same process, we have a short time window where a race happens and can result in a memory leak. The race happens like this: 1) A program opens a file descriptor for a file and then spawns two threads (with the pthreads library for example), lets call them task A and task B; 2) Task A calls lseek with SEEK_DATA or SEEK_HOLE and ends up at file.c:find_desired_extent() while holding a read lock on the inode; 3) At the start of find_desired_extent(), it extracts the file's private_data pointer into a local variable named 'private', which has a value of NULL; 4) Task B also calls lseek with SEEK_DATA or SEEK_HOLE, locks the inode in shared mode and enters file.c:find_desired_extent(), where it also extracts file->private_data into its local variable 'private', which has a NULL value; 5) Because it saw a NULL file private, task A allocates a private structure and assigns to the file structure; 6) Task B also saw a NULL file private so it also allocates its own file private and then assigns it to the same file structure, since both tasks are using the same file descriptor. At this point we leak the private structure allocated by task A. Besides the memory leak, there's also the detail that both tasks end up using the same cached state record in the private structure (struct btrfs_file_private::llseek_cached_state), which can result in a use-after-free problem since one task can free it while the other is still using it (only one task took a reference count on it). Also, sharing the cached state is not a good idea since it could result in incorrect results in the future - right now it should not be a problem because it end ups being used only in extent-io-tree.c:count_range_bits() where we do range validation before using the cached state. Fix this by protecting the private assignment and check of a file while holding the inode's spinlock and keep track of the task that allocated the private, so that it's used only by that task in order to prevent user-after-free issues with the cached state record as well as potentially using it incorrectly in the future.
(CVE-2024-47741)
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: High
ID: 295716
ファイル名: azure_linux_CVE-2024-47741.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: 6.7
CVSS v2
リスクファクター: Medium
基本値: 6
現状値: 4.4
ベクトル: CVSS2#AV:L/AC:H/Au:S/C:C/I:C/A:C
CVSS スコアのソース: CVE-2024-47741
CVSS v3
リスクファクター: High
基本値: 7
現状値: 6.1
ベクトル: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/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-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: 2024/11/12
脆弱性公開日: 2024/10/21
参照情報
CVE: CVE-2024-47741