Linux Distros のパッチ未適用の脆弱性: CVE-2025-39879
medium Nessus プラグイン ID 265861
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概要
Linux/Unix ホストには、ベンダーにより修正されていないことを示す脆弱性を持つ複数のパッケージがインストールされています。説明
Linux/Unix ホストには、ベンダーが提供するパッチが利用できない脆弱性の影響を受ける複数のパッケージがインストールされています。- Linux カーネルでは、以下の脆弱性が解決されています: ceph: always call ceph_shift_unused_folios_left() The function ceph_process_folio_batch() sets folio_batch entries to NULL, which is an illegal state. Before folio_batch_release() crashes due to this API violation, the function ceph_shift_unused_folios_left() is supposed to remove those NULLs from the array. However, since commit ce80b76dd327 (ceph: introduce ceph_process_folio_batch() method), this shifting doesn't happen anymore because the for loop got moved to ceph_process_folio_batch(), and now the `i` variable that remains in ceph_writepages_start() doesn't get incremented anymore, making the shifting effectively unreachable much of the time. Later, commit 1551ec61dc55 (ceph: introduce ceph_submit_write() method) added more preconditions for doing the shift, replacing the `i` check (with something that is still just as broken):
- if ceph_process_folio_batch() fails, shifting never happens - if ceph_move_dirty_page_in_page_array() was never called (because ceph_process_folio_batch() has returned early for some of various reasons), shifting never happens - if `processed_in_fbatch` is zero (because ceph_process_folio_batch() has returned early for some of the reasons mentioned above or because ceph_move_dirty_page_in_page_array() has failed), shifting never happens Since those two commits, any problem in ceph_process_folio_batch() could crash the kernel, e.g. this way: BUG: kernel NULL pointer dereference, address: 0000000000000034 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: Oops: 0002 [#1] SMP NOPTI CPU: 172 UID: 0 PID: 2342707 Comm: kworker/u778:8 Not tainted 6.15.10-cm4all1-es #714 NONE Hardware name: Dell Inc. PowerEdge R7615/0G9DHV, BIOS 1.6.10 12/08/2023 Workqueue: writeback wb_workfn (flush-ceph-1) RIP: 0010:folios_put_refs+0x85/0x140 Code: 83 c5 01 39 e8 7e 76 48 63 c5 49 8b 5c c4 08 b8 01 00 00 00 4d 85 ed 74 05 41 8b 44 ad 00 48 8b 15 b0 > RSP: 0018:ffffb880af8db778 EFLAGS: 00010207 RAX:
0000000000000001 RBX: 0000000000000000 RCX: 0000000000000003 RDX: ffffe377cc3b0000 RSI: 0000000000000000 RDI: ffffb880af8db8c0 RBP: 0000000000000000 R08: 000000000000007d R09: 000000000102b86f R10:
0000000000000001 R11: 00000000000000ac R12: ffffb880af8db8c0 R13: 0000000000000000 R14: 0000000000000000 R15: ffff9bd262c97000 FS: 0000000000000000(0000) GS:ffff9c8efc303000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000034 CR3: 0000000160958004 CR4: 0000000000770ef0 PKRU: 55555554 Call Trace: <TASK> ceph_writepages_start+0xeb9/0x1410 The crash can be reproduced easily by changing the ceph_check_page_before_write() return value to `-E2BIG`. (Interestingly, the crash happens only if `huge_zero_folio` has already been allocated; without `huge_zero_folio`, is_huge_zero_folio(NULL) returns true and folios_put_refs() skips NULL entries instead of dereferencing them. That makes reproducing the bug somewhat unreliable. See https://lore.kernel.org/[email protected] for a discussion of this detail.) My suggestion is to move the ceph_shift_unused_folios_left() to right after ceph_process_folio_batch() to ensure it always gets called to fix up the illegal folio_batch state. (CVE-2025-39879)
Nessus は、ベンダーによって報告されたパッケージの存在に依存していることに注意してください。
ソリューション
現時点で既知の解決策はありません。参考資料
プラグインの詳細
深刻度: Medium
ID: 265861
ファイル名: unpatched_CVE_2025_39879.nasl
バージョン: 1.3
タイプ: local
エージェント: unix
ファミリー: Misc.
公開日: 2025/9/25
更新日: 2025/11/25
サポートされているセンサー: Agentless Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, 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: Medium
基本値: 4.9
現状値: 4.2
ベクトル: CVSS2#AV:L/AC:L/Au:N/C:N/I:N/A:C
CVSS スコアのソース: CVE-2025-39879
CVSS v3
リスクファクター: Medium
基本値: 5.5
現状値: 5.1
ベクトル: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
現状ベクトル: CVSS:3.0/E:U/RL:U/RC:C
脆弱性情報
CPE: cpe:/o:canonical:ubuntu_linux:20.04:-:lts, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-lowlatency-hwe-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-aws-5.3, p-cpe:/a:canonical:ubuntu_linux:linux-azure-6.11, p-cpe:/a:canonical:ubuntu_linux:linux-hwe, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-5.8, p-cpe:/a:canonical:ubuntu_linux:linux-oracle-6.5, p-cpe:/a:canonical:ubuntu_linux:linux-oem-5.17, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-6.2, p-cpe:/a:canonical:ubuntu_linux:linux-aws-5.0, p-cpe:/a:canonical:ubuntu_linux:linux-oem-6.5, p-cpe:/a:canonical:ubuntu_linux:linux-intel, p-cpe:/a:canonical:ubuntu_linux:linux-azure-5.19, cpe:/o:canonical:ubuntu_linux:16.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-realtime, p-cpe:/a:canonical:ubuntu_linux:linux-azure-5.13, p-cpe:/a:canonical:ubuntu_linux:linux-raspi2, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-6.2, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-6.11, p-cpe:/a:canonical:ubuntu_linux:linux-azure-5.8, p-cpe:/a:canonical:ubuntu_linux:linux-nvidia-6.2, p-cpe:/a:canonical:ubuntu_linux:linux-oracle-5.0, p-cpe:/a:canonical:ubuntu_linux:linux-oracle-5.13, p-cpe:/a:canonical:ubuntu_linux:linux-oem, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-6.5, p-cpe:/a:canonical:ubuntu_linux:linux-riscv-5.8, p-cpe:/a:canonical:ubuntu_linux:linux-starfive-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-aws-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-5.13, p-cpe:/a:canonical:ubuntu_linux:linux-oem-5.14, p-cpe:/a:canonical:ubuntu_linux:linux-gcp, p-cpe:/a:canonical:ubuntu_linux:linux-azure, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-5.3, p-cpe:/a:canonical:ubuntu_linux:linux-gke-5.15, p-cpe:/a:canonical:ubuntu_linux:linux-lowlatency-hwe-6.5, p-cpe:/a:canonical:ubuntu_linux:linux-azure-5.3, p-cpe:/a:canonical:ubuntu_linux:linux-starfive-6.5, p-cpe:/a:canonical:ubuntu_linux:linux-oem-5.6, p-cpe:/a:canonical:ubuntu_linux:linux-riscv-6.5, p-cpe:/a:canonical:ubuntu_linux:linux-oracle-5.8, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-gkeop-5.4, p-cpe:/a:canonical:ubuntu_linux:linux-lowlatency-hwe-6.11, p-cpe:/a:canonical:ubuntu_linux:linux-lowlatency-hwe-6.2, p-cpe:/a:canonical:ubuntu_linux:linux-allwinner-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-5.8, p-cpe:/a:canonical:ubuntu_linux:linux-gkeop-5.15, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-5.13, p-cpe:/a:canonical:ubuntu_linux:linux-raspi-realtime, p-cpe:/a:canonical:ubuntu_linux:linux-azure-fde-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-intel-iot-realtime, p-cpe:/a:canonical:ubuntu_linux:linux-gkeop, p-cpe:/a:canonical:ubuntu_linux:linux-oracle-5.11, p-cpe:/a:canonical:ubuntu_linux:linux-riscv-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-oracle-5.3, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-edge, p-cpe:/a:canonical:ubuntu_linux:linux-aws-5.13, p-cpe:/a:canonical:ubuntu_linux:linux-oem-6.11, p-cpe:/a:canonical:ubuntu_linux:linux-aws-5.11, p-cpe:/a:canonical:ubuntu_linux:linux-gke-4.15, p-cpe:/a:canonical:ubuntu_linux:linux-aws-5.8, p-cpe:/a:canonical:ubuntu_linux:linux-oem-6.0, p-cpe:/a:canonical:ubuntu_linux:linux-azure-6.2, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-6.11, p-cpe:/a:canonical:ubuntu_linux:linux-aws-6.2, p-cpe:/a:canonical:ubuntu_linux:linux-gke, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-5.19, p-cpe:/a:canonical:ubuntu_linux:linux-intel-5.13, p-cpe:/a:canonical:ubuntu_linux:linux-gke-5.4, p-cpe:/a:canonical:ubuntu_linux:linux-azure-edge, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-5.11, p-cpe:/a:canonical:ubuntu_linux:linux-azure-6.5, p-cpe:/a:canonical:ubuntu_linux:linux-oem-5.13, p-cpe:/a:canonical:ubuntu_linux:linux-aws-6.5, p-cpe:/a:canonical:ubuntu_linux:linux-gcp-5.11, p-cpe:/a:canonical:ubuntu_linux:linux-azure-fde, p-cpe:/a:canonical:ubuntu_linux:linux-nvidia-6.5, p-cpe:/a:canonical:ubuntu_linux:linux-hwe-6.5, p-cpe:/a:canonical:ubuntu_linux:linux-azure-5.11, p-cpe:/a:canonical:ubuntu_linux:linux-starfive-6.2, p-cpe:/a:canonical:ubuntu_linux:linux-oem-6.8, p-cpe:/a:canonical:ubuntu_linux:linux-riscv-5.11, p-cpe:/a:canonical:ubuntu_linux:linux-oem-6.1, p-cpe:/a:canonical:ubuntu_linux:linux-riscv, p-cpe:/a:canonical:ubuntu_linux:linux-azure-fde-6.2, p-cpe:/a:canonical:ubuntu_linux:linux-oem-5.10
必要な KB アイテム: Host/cpu, Host/local_checks_enabled, global_settings/vendor_unpatched, Host/OS/identifier
エクスプロイトの容易さ: No known exploits are available
脆弱性公開日: 2025/9/23
参照情報
CVE: CVE-2025-39879