CentOS Linux 8.4 [TuxCare] セキュリティ更新プログラム:bpftool/kernel/kernel-core/kernel-cross-headers/etcの複数の脆弱性(CENTOS8.4:CLSA-2026:1786435880)

high Nessus プラグイン ID 361958

概要

CentOS 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

CentOS Linux 8.4 ホストには、TuxCare CENTOS8.4:CLSA-2026:1786435880アドバイザリに記載されている複数の脆弱性の影響を受ける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: RDMA/siw: Fix a use after free in siw_alloc_mr Our code analyzer reported a UAF. In siw_alloc_mr(), it calls siw_mr_add_mem(mr,..). In the implementation of siw_mr_add_mem(), mem is assigned to mr->mem and then mem is freed via kfree(mem) if xa_alloc_cyclic() failed. Here, mr->mem still point to a freed object. After, the execution continue up to the err_out branch of siw_alloc_mr, and the freed mr->mem is used in siw_mr_drop_mem(mr). My patch moves mr->mem = mem behind the if (xa_alloc_cyclic(..)<0) {} section, to avoid the uaf. (CVE-2021-47012)

- Linux カーネルでは、以下の脆弱性が解決されています: net: bonding: fix use-after-free after 802.3ad slave unbind commit 0622cab0341c (bonding: fix 802.3ad aggregator reselection), resolve case, when there is several aggregation groups in the same bond. bond_3ad_unbind_slave will invalidate (clear) aggregator when __agg_active_ports return zero. So, ad_clear_agg can be executed even, when num_of_ports!=0. Than bond_3ad_unbind_slave can be executed again for, previously cleared aggregator.
NOTE: at this time bond_3ad_unbind_slave will not update slave ports list, because lag_ports==NULL. So, here we got slave ports, pointing to freed aggregator memory. Fix with checking actual number of ports in group (as was before commit 0622cab0341c (bonding: fix 802.3ad aggregator reselection) ), before ad_clear_agg(). The KASAN logs are as follows: [ 767.617392] ================================================================== [ 767.630776] BUG: KASAN: use-after-free in bond_3ad_state_machine_handler+0x13dc/0x1470 [ 767.638764] Read of size 2 at addr ffff00011ba9d430 by task kworker/u8:7/767 [ 767.647361] CPU: 3 PID: 767 Comm: kworker/u8:7 Tainted: G O 5.15.11 #15 [767.655329] Hardware name: DNI AmazonGo1 A7040 board (DT) [ 767.660760] Workqueue: lacp_1 bond_3ad_state_machine_handler [ 767.666468] Call trace: [ 767.668930] dump_backtrace+0x0/0x2d0 [767.672625] show_stack+0x24/0x30 [ 767.675965] dump_stack_lvl+0x68/0x84 [ 767.679659] print_address_description.constprop.0+0x74/0x2b8 [ 767.685451] kasan_report+0x1f0/0x260 [ 767.689148]
__asan_load2+0x94/0xd0 [ 767.692667] bond_3ad_state_machine_handler+0x13dc/0x1470 (CVE-2022-49667)

- Linux カーネルでは、以下の脆弱性が解決されています: arp: use RCU protection in arp_xmit() arp_xmit() can be called without RTNL or RCU protection. Use RCU protection to avoid potential UAF.
(CVE-2025-21762)

- Linux カーネルでは、以下の脆弱性が解決されています: netfilter: nf_conntrack_h323: fix OOB read in decode_choice() In decode_choice(), the boundary check before get_len() uses the variable `len`, which is still 0 from its initialization at the top of the function: unsigned int type, ext, len = 0; ...
if (ext || (son->attr & OPEN)) { BYTE_ALIGN(bs); if (nf_h323_error_boundary(bs, len, 0)) /* len is 0 here
*/ return H323_ERROR_BOUND; len = get_len(bs); /* OOB read */ When the bitstream is exactly consumed (bs->cur == bs->end), the check nf_h323_error_boundary(bs, 0, 0) evaluates to (bs->cur + 0 > bs->end), which is false. The subsequent get_len() call then dereferences *bs->cur++, reading 1 byte past the end of the buffer. If that byte has bit 7 set, get_len() reads a second byte as well. This can be triggered remotely by sending a crafted Q.931 SETUP message with a User-User Information Element containing exactly 2 bytes of PER-encoded data ({0x08, 0x00}) to port 1720 through a firewall with the nf_conntrack_h323 helper active. The decoder fully consumes the PER buffer before reaching this code path, resulting in a 1-2 byte heap-buffer-overflow read confirmed by AddressSanitizer. Fix this by checking for 2 bytes (the maximum that get_len() may read) instead of the uninitialized `len`. This matches the pattern used at every other get_len() call site in the same file, where the caller checks for 2 bytes of available data before calling get_len(). (CVE-2026-43233)

- Linux カーネルでは、以下の脆弱性が解決されています: Bluetooth: SMP: force responder MITM requirements before building the pairing response smp_cmd_pairing_req() currently builds the pairing response from the initiator auth_req before enforcing the local BT_SECURITY_HIGH requirement. If the initiator omits SMP_AUTH_MITM, the response can also omit it even though the local side still requires MITM. tk_request() then sees an auth value without SMP_AUTH_MITM and may select JUST_CFM, making method selection inconsistent with the pairing policy the responder already enforces. When the local side requires HIGH security, first verify that MITM can be achieved from the IO capabilities and then force SMP_AUTH_MITM in the response in both rsp.auth_req and auth. This keeps the responder auth bits and later method selection aligned. (CVE-2026-43334)

Nessus はこれら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

TuxCareアドバイザリCENTOS8.4:CLSA-2026:1786435880のガイダンスに基づいて、影響を受けるパッケージを更新してください。

参考資料

https://cve.tuxcare.com/els/releases/CLSA-2026:1786435880

http://www.nessus.org/u?5aec418c

プラグインの詳細

深刻度: High

ID: 361958

ファイル名: tuxcare_centos_8.4_CLSA-2026-1786435880.nasl

バージョン: 1.1

タイプ: Local

エージェント: unix

公開日: 2026/10/1

更新日: 2026/10/1

サポートされているセンサー: Continuous Assessment, Nessus Agent, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

リスク情報

VPR

リスクファクター: High

スコア: 8

パーセンタイル: 99.68

Vendor

Vendor Severity: Important

CVSS v2

リスクファクター: Medium

基本値: 6.8

現状値: 5.3

ベクトル: CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C

CVSS スコアのソース: CVE-2026-53112

CVSS v3

リスクファクター: High

基本値: 7.8

現状値: 7

ベクトル: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

現状ベクトル: CVSS:3.0/E:P/RL:O/RC:C

脆弱性情報

必要な KB アイテム: Host/OS/extended-third-party, Host/local_checks_enabled, Host/CentOS/release, Host/CentOS/rpm-list

エクスプロイトが利用可能: true

エクスプロイトの容易さ: Exploits are available

パッチ公開日: 2026/8/11

脆弱性公開日: 2021/7/21

参照情報

CVE: CVE-2021-47012, CVE-2022-49667, CVE-2025-21762, CVE-2026-43233, CVE-2026-43334, CVE-2026-43339, CVE-2026-46234, CVE-2026-53064, CVE-2026-53112, CVE-2026-64561

CLSA: 2026:1786435880