CentOS Linux 8 [TuxCare] 安全性更新：bpftool / kernel / kernel-core / kernel-cross-headers / etc多個漏洞 （CENTOS-STREAM8：CLSA-2026：1783790425）
critical Nessus Plugin ID 352893
語言:
概要
CentOS Linux 主機缺少一個或多個安全性更新。說明
CentOS Linux 8 主機安裝的套件受到 TuxCare CENTOS-STREAM8：CLSA-2026：1783790425 公告中提及的多個弱點影響。- netfilter 中的缺陷可讓連線攻擊者推斷 openvpn 連線端點資訊，以便進一步使用這些資訊發動傳統網路攻擊。(CVE-2021-3773)
- 在代理虛擬化 TPM 裝置的 Linux 核心實作中發現缺陷。在已設定虛擬化 TPM 裝置的系統上 (非預設設定)，本機攻擊者可建立釋放後使用情形，並造成可在系統上提升權限的狀況。 (CVE-2022-2977)
- 已解決 Linux 核心中的下列弱點：tracing: Free buffers when a used dynamic event is removed After 65536 dynamic events have been added and removed, the type field of the event then uses the first type number that is available (not currently used by other events). A type number is the identifier of the binary blobs in the tracing ring buffer (known as events) to map them to logic that can parse the binary blob. The issue is that if a dynamic event (like a kprobe event) is traced and is in the ring buffer, and then that event is removed (because it is dynamic, which means it can be created and destroyed), if another dynamic event is created that has the same number that new event's logic on parsing the binary blob will be used. To show how this can be an issue, the following can crash the kernel: # cd /sys/kernel/tracing # for i in `seq 65536`; do echo 'p:kprobes/foo do_sys_openat2 $arg1:u32' > kprobe_events # done For every iteration of the above, the writing to the kprobe_events will remove the old event and create a new one (with the same format) and increase the type number to the next available on until the type number reaches over 65535 which is the max number for the 16 bit type. After it reaches that number, the logic to allocate a new number simply looks for the next available number.
When an dynamic event is removed, that number is then available to be reused by the next dynamic event created. That is, once the above reaches the max number, the number assigned to the event in that loop will remain the same. Now that means deleting one dynamic event and created another will reuse the previous events type number. This is where bad things can happen. After the above loop finishes, the kprobes/foo event which reads the do_sys_openat2 function call's first parameter as an integer. # echo 1 > kprobes/foo/enable # cat /etc/passwd > /dev/null # cat trace cat-2211 [005] .... 2007.849603: foo:
(do_sys_openat2+0x0/0x130) arg1=4294967196 cat-2211 [005] .... 2007.849620: foo:
(do_sys_openat2+0x0/0x130) arg1=4294967196 cat-2211 [005] .... 2007.849838: foo:
(do_sys_openat2+0x0/0x130) arg1=4294967196 cat-2211 [005] .... 2007.849880: foo:
(do_sys_openat2+0x0/0x130) arg1=4294967196 # echo 0 > kprobes/foo/enable Now if we delete the kprobe and create a new one that reads a string: # echo 'p:kprobes/foo do_sys_openat2 +0($arg2):string' > kprobe_events And now we can the trace: # cat trace sendmail-1942 [002] ..... 530.136320: foo:
(do_sys_openat2+0x0/0x240) arg1= cat-2046 [004] ..... 530.930817: foo: (do_sys_openat2+0x0/0x240) arg1= cat-2046 [004] ..... 530.930961: foo: (do_sys_openat2+0x0/0x240) arg1= cat-2046 [004] ..... 530.934278: foo: (do_sys_openat2+0x0/0x240) arg1= cat-2046 [004] ..... 530.934563: foo: (do_sys_openat2+0x0/0x240) arg1= ---truncated--- (CVE-2022-49006)
- 已解決 Linux 核心中的下列弱點：tpm: fix reference counting for struct tpm_chip The following sequence of operations results in a refcount warning: 1. Open device /dev/tpmrm. 2.
Remove module tpm_tis_spi. 3. Write a TPM command to the file descriptor opened at step 1. ------------[cut here ]------------ WARNING: CPU: 3 PID: 1161 at lib/refcount.c:25 kobject_get+0xa0/0xa4 refcount_t:
addition on 0; use-after-free. Modules linked in: tpm_tis_spi tpm_tis_core tpm mdio_bcm_unimac brcmfmac sha256_generic libsha256 sha256_arm hci_uart btbcm bluetooth cfg80211 vc4 brcmutil ecdh_generic ecc snd_soc_core crc32_arm_ce libaes raspberrypi_hwmon ac97_bus snd_pcm_dmaengine bcm2711_thermal snd_pcm snd_timer genet snd phy_generic soundcore [last unloaded: spi_bcm2835] CPU: 3 PID: 1161 Comm: hold_open Not tainted 5.10.0ls-main-dirty #2 Hardware name: BCM2711 [<c0410c3c>] (unwind_backtrace) from [<c040b580>] (show_stack+0x10/0x14) [<c040b580>] (show_stack) from [<c1092174>] (dump_stack+0xc4/0xd8) [<c1092174>] (dump_stack) from [<c0445a30>] (__warn+0x104/0x108) [<c0445a30>] (__warn) from [<c0445aa8>] (warn_slowpath_fmt+0x74/0xb8) [<c0445aa8>] (warn_slowpath_fmt) from [<c08435d0>] (kobject_get+0xa0/0xa4) [<c08435d0>] (kobject_get) from [<bf0a715c>] (tpm_try_get_ops+0x14/0x54 [tpm]) [<bf0a715c>] (tpm_try_get_ops [tpm]) from [<bf0a7d6c>] (tpm_common_write+0x38/0x60 [tpm]) [<bf0a7d6c>] (tpm_common_write [tpm]) from [<c05a7ac0>] (vfs_write+0xc4/0x3c0) [<c05a7ac0>] (vfs_write) from [<c05a7ee4>] (ksys_write+0x58/0xcc) [<c05a7ee4>] (ksys_write) from [<c04001a0>] (ret_fast_syscall+0x0/0x4c) Exception stack(0xc226bfa8 to 0xc226bff0) bfa0: 00000000 000105b4 00000003 beafe664 00000014 00000000 bfc0: 00000000 000105b4 000103f8 00000004 00000000 00000000 b6f9c000 beafe684 bfe0: 0000006c beafe648 0001056c b6eb6944 ---[ end trace d4b8409def9b8b1f ]--- The reason for this warning is the attempt to get the chip->dev reference in tpm_common_write() although the reference counter is already zero. Since commit 8979b02aaf1d (tpm: Fix reference count to main device) the extra reference used to prevent a premature zero counter is never taken, because the required TPM_CHIP_FLAG_TPM2 flag is never set. Fix this by moving the TPM 2 character device handling from tpm_chip_alloc() to tpm_add_char_device() which is called at a later point in time when the flag has been set in case of TPM2.
Commit fdc915f7f719 (tpm: expose spaces via a device link /dev/tpmrm<n>) already introduced function tpm_devs_release() to release the extra reference but did not implement the required put on chip->devs that results in the call of this function. Fix this by putting chip->devs in tpm_chip_unregister().
Finally move the new implementation for the TPM 2 handling into a new function to avoid multiple checks for the TPM_CHIP_FLAG_TPM2 flag in the good case and error cases. (CVE-2022-49287)
- 已解決 Linux 核心中的下列弱點：tracing: Fix wild-memory-access in register_synth_event() In register_synth_event(), if set_synth_event_print_fmt() failed, then both trace_remove_event_call() and unregister_trace_event() will be called, which means the trace_event_call will call __unregister_trace_event() twice. As the result, the second unregister will causes the wild-memory-access. register_synth_event set_synth_event_print_fmt failed trace_remove_event_call event_remove if call->event.funcs then __unregister_trace_event (first call) unregister_trace_event
__unregister_trace_event (second call) Fix the bug by avoiding to call the second
__unregister_trace_event() by checking if the first one is called. general protection fault, probably for non-canonical address 0xfbd59c0000000024: 0000 [#1] SMP KASAN PTI KASAN: maybe wild-memory-access in range [0xdead000000000120-0xdead000000000127] CPU: 0 PID: 3807 Comm: modprobe Not tainted 6.1.0-rc1-00186-g76f33a7eedb4 #299 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014 RIP: 0010:unregister_trace_event+0x6e/0x280 Code:
00 fc ff df 4c 89 ea 48 c1 ea 03 80 3c 02 00 0f 85 0e 02 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 63 08 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 e2 01 00 00 49 89 2c 24 48 85 ed 74 28 e8 7a 9b RSP:
0018:ffff88810413f370 EFLAGS: 00010a06 RAX: dffffc0000000000 RBX: ffff888105d050b0 RCX: 0000000000000000 RDX: 1bd5a00000000024 RSI: ffff888119e276e0 RDI: ffffffff835a8b20 RBP: dead000000000100 R08:
0000000000000000 R09: fffffbfff0913481 R10: ffffffff8489a407 R11: fffffbfff0913480 R12: dead000000000122 R13: ffff888105d050b8 R14: 0000000000000000 R15: ffff888105d05028 FS: 00007f7823e8d540(0000) GS:ffff888119e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2:
00007f7823e7ebec CR3: 000000010a058002 CR4: 0000000000330ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK>
__create_synth_event+0x1e37/0x1eb0 create_or_delete_synth_event+0x110/0x250 synth_event_run_command+0x2f/0x110 test_gen_synth_cmd+0x170/0x2eb [synth_event_gen_test] synth_event_gen_test_init+0x76/0x9bc [synth_event_gen_test] do_one_initcall+0xdb/0x480 do_init_module+0x1cf/0x680 load_module+0x6a50/0x70a0 __do_sys_finit_module+0x12f/0x1c0 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd (CVE-2022-49799)
請注意，Nessus 並未測試這些問題，而是僅依據應用程式自我報告的版本號碼作出判斷。
解決方案
根據 TuxCare 公告 CENTOS-STREAM8：CLSA-2026：1783790425 中的指引更新受影響的套件。另請參閱
Plugin 詳細資訊
嚴重性: Critical
ID: 352893
檔案名稱: tuxcare_centos_8_CLSA-2026-1783790425.nasl
版本: 1.6
類型: Local
代理程式: unix
已發布: 2026/9/30
已更新: 2026/10/20
支援的感應器: Nessus Agent, Continuous Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus
風險資訊
VPR
風險因素: Critical
分數: 9.5
百分位數: 99.87
Vendor
Vendor Severity: Critical
CVSS v2
風險因素: High
基本分數: 7.5
時間性分數: 6.5
媒介: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P
CVSS 評分資料來源: CVE-2021-3773
CVSS v3
風險因素: Critical
基本分數: 9.8
時間性分數: 9.4
媒介: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
時間媒介: CVSS:3.0/E:H/RL:O/RC:C
弱點資訊
必要的 KB 項目: Host/local_checks_enabled, Host/CentOS/release, Host/CentOS/rpm-list, Host/OS/extended-third-party
可被惡意程式利用: true
可輕鬆利用: Exploits are available
修補程式發佈日期: 2026/7/11
弱點發布日期: 2021/7/21
參考資訊
CVE: CVE-2021-3773, CVE-2022-2977, CVE-2022-49006, CVE-2022-49287, CVE-2022-49799, CVE-2022-49826, CVE-2022-50021, CVE-2022-50453, CVE-2023-52652, CVE-2023-53053, CVE-2024-56664, CVE-2025-38068, CVE-2025-68183, CVE-2025-71068, CVE-2026-23076, CVE-2026-23078, CVE-2026-23392, CVE-2026-23397, CVE-2026-23448, CVE-2026-31402, CVE-2026-31408, CVE-2026-31419, CVE-2026-31452, CVE-2026-31488, CVE-2026-31500, CVE-2026-31527, CVE-2026-31586, CVE-2026-31669, CVE-2026-31786, CVE-2026-31787, CVE-2026-43050, CVE-2026-43051, CVE-2026-43052, CVE-2026-43088, CVE-2026-43125, CVE-2026-43328, CVE-2026-43329, CVE-2026-43427, CVE-2026-43493, CVE-2026-43499, CVE-2026-80676
CLSA: 2026:1783790425