CentOS Linux 7 [TuxCare] 安全更新：bpftool / kernel / kernel-debug / kernel-debug-devel / kernel-devel / 等多个漏洞 （CENTOS7：CLSA-2026：1791730242）
high Nessus 插件 ID 366515
语言：
简介
CentOS Linux 主机缺少一个或多个安全更新。描述
如 TuxCare CENTOS7：CLSA-2026：1791730242公告所述，CentOS Linux 7 主机上安装的程序包受到多个漏洞的影响。- Linux 内核 netfilter: nf_tables 组件中存在一个释放后使用漏洞，攻击者可利用此漏洞以实现本地特权提升。由于 nf_tables netlink 控制平面事务和 nft_set 元素垃圾收集之间存在竞争条件，引用计数器可能下溢，从而导致释放后使用漏洞。我们建议升级过去的 commit 3e91b0ebd994635df2346353322ac51ce84ce6d8。(CVE-2023-4244)
- 已修复 Linux 内核中的下列漏洞：crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg Issuing two writes to the same af_alg socket is bogus as the data will be interleaved in an unpredictable fashion. Furthermore, concurrent writes may create inconsistencies in the internal socket state. Disallow this by adding a new ctx->write field that indiciates exclusive ownership for writing. (CVE-2025-39964)
- 已修复 Linux 内核中的下列漏洞：net: atm: fix crash due to unvalidated vcc pointer in sigd_send() Reproducer available at [1]. The ATM send path (sendmsg -> vcc_sendmsg -> sigd_send) reads the vcc pointer from msg->vcc and uses it directly without any validation. This pointer comes from userspace via sendmsg() and can be arbitrarily forged: int fd = socket(AF_ATMSVC, SOCK_DGRAM, 0); ioctl(fd, ATMSIGD_CTRL); // become ATM signaling daemon struct msghdr msg = { .msg_iov = &iov, ... };
*(unsigned long *)(buf + 4) = 0xdeadbeef; // fake vcc pointer sendmsg(fd, &msg, 0); // kernel dereferences 0xdeadbeef In normal operation, the kernel sends the vcc pointer to the signaling daemon via sigd_enq() when processing operations like connect(), bind(), or listen(). The daemon is expected to return the same pointer when responding. However, a malicious daemon can send arbitrary pointer values. Fix this by introducing find_get_vcc() which validates the pointer by searching through vcc_hash (similar to how sigd_close() iterates over all VCCs), and acquires a reference via sock_hold() if found. Since struct atm_vcc embeds struct sock as its first member, they share the same lifetime. Therefore using sock_hold/sock_put is sufficient to keep the vcc alive while it is being used. Note that there may be a race with sigd_close() which could mark the vcc with various flags (e.g., ATM_VF_RELEASED) after find_get_vcc() returns. However, sock_hold() guarantees the memory remains valid, so this race only affects the logical state, not memory safety. [1]:
https://gist.github.com/mrpre/1ba5949c45529c511152e2f4c755b0f3 (CVE-2026-31411)
- 已修复 Linux 内核中的下列漏洞：ipc: limit next_id allocation to the valid ID range The checkpoint/restore sysctl path can request the next SysV IPC id through ids->next_id.
ipc_idr_alloc() currently forwards that request to idr_alloc() with an open-ended upper bound. If the valid tail of the SysV IPC id space is full, the allocation can spill beyond ipc_mni. The returned SysV IPC id still uses the normal index encoding, so later lookup and removal can target the wrong slot. This leaves the real IDR entry behind and breaks the IDR state for the object. The bug is in ipc_idr_alloc() in the checkpoint/restore path. 1. ids->next_id is passed to: idr_alloc(&ids->ipcs_idr, new, ipcid_to_idx(next_id), 0, ...) 2. The zero upper bound makes the allocation effectively open-ended. Once the valid SysV IPC tail is occupied, idr_alloc() can spill past ipc_mni and allocate an entry beyond the valid IPC id range. 3. The new object id is still encoded with the narrower SysV IPC index width: new->id = (new->seq << ipcmni_seq_shift()) + idx 4. Later removal goes through ipc_rmid(), which uses:
ipcid_to_idx(ipcp->id) That truncates the real IDR index. An object actually stored at a high index can then be removed as if it lived at a low in-range index. 5. For shared memory, shm_destroy() frees the current object anyway, but the real high IDR slot is left behind as a dangling pointer. 6. A subsequent walk of /proc/sysvipc/shm reaches the stale IDR entry and dereferences freed memory. Prevent this by bounding the requested allocation to ipc_mni so the checkpoint/restore path fails once the valid range is exhausted. (CVE-2026-52923)
- 已修复 Linux 内核中的下列漏洞：dm log: fix out-of-bounds write due to region_count overflow The local variable region_count in create_log_context() is declared as unsigned int (32-bit), but dm_sector_div_up() returns sector_t (64-bit). When a device-mapper target has a sufficiently large ti->len with a small region_size, the division result can exceed UINT_MAX. The truncated value is then used to calculate bitset_size, causing clean_bits, sync_bits, and recovering_bits to be allocated far smaller than needed for the actual number of regions. Subsequent log operations (log_set_bit, log_clear_bit, log_test_bit) use region indices derived from the full untruncated region space, causing out-of-bounds writes to kernel heap memory allocated by vmalloc. This can be reproduced by creating a mirror target whose region_count overflows 32 bits: dmsetup create bigzero --table '0 8589934594 zero' dmsetup create mymirror --table '0 8589934594 mirror \ core 2 2 nosync 2 /dev/mapper/bigzero 0 \ /dev/mapper/bigzero 0' The status output confirms the truncation (sync_count=1 instead of 4294967297, because 0x100000001 was truncated to 1): $ dmsetup status mymirror 0 8589934594 mirror 2 254:1 254:1 1/4294967297 ... This leads to a kernel crash in core_in_sync: BUG: scheduling while atomic: (udev-worker)/9150/0x00000000 RIP: 0010:core_in_sync+0x14/0x30 [dm_log] CR2: 0000000000000008 Fixing recursive fault but reboot is needed! Fix by widening the local region_count to sector_t and adding an explicit overflow check before the value is assigned to lc->region_count. (CVE-2026-53059)
请注意，Nessus 尚未测试这些问题，而是只依据应用程序自我报告的版本号进行判断。
解决方案
根据 TuxCare 公告 CENTOS7：CLSA-2026：1791730242 中的指南更新受影响的程序包。另见
插件详情
严重性: High
ID: 366515
文件名: tuxcare_centos_7_CLSA-2026-1791730242.nasl
版本: 1.1
类型: Local
代理: unix
发布时间: 2026/10/16
最近更新时间: 2026/10/16
支持的传感器: Nessus Agent, Continuous Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus
风险信息
VPR
风险因素: Critical
分数: 9.3
百分位: 99.82
Vendor
Vendor Severity: Important
CVSS v2
风险因素: High
基本分数: 7.2
时间分数: 6
矢量: CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C
CVSS 分数来源: CVE-2026-53196
CVSS v3
风险因素: High
基本分数: 7.8
时间分数: 7.2
矢量: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
时间矢量: CVSS:3.0/E:F/RL:O/RC:C
CVSS 分数来源: CVE-2026-64343
漏洞信息
必需的 KB 项: Host/local_checks_enabled, Host/CentOS/release, Host/CentOS/rpm-list, Host/OS/extended-third-party
可利用: true
易利用性: Exploits are available
补丁发布日期: 2026/10/11
漏洞发布日期: 2023/9/6
CISA 已知可遭利用的漏洞到期日期: 2026/9/21
参考资料信息
CVE: CVE-2023-4244, CVE-2025-39964, CVE-2026-31411, CVE-2026-31688, CVE-2026-52923, CVE-2026-53059, CVE-2026-53195, CVE-2026-53196, CVE-2026-53266, CVE-2026-64191, CVE-2026-64340, CVE-2026-64343, CVE-2026-64372, CVE-2026-64375, CVE-2026-68106, CVE-2026-68111, CVE-2026-68175, CVE-2026-68218, CVE-2026-68234, CVE-2026-68299, CVE-2026-68425, CVE-2026-72005, CVE-2026-72019, CVE-2026-72020, CVE-2026-72036, CVE-2026-72039, CVE-2026-72083, CVE-2026-72106, CVE-2026-74720, CVE-2026-80844, CVE-2026-81000
CLSA: 2026:1791730242