Linux Distros 未修补的漏洞: CVE-2021-47632
high Nessus 插件 ID 230092
语言：
简介
Linux/Unix 主机上安装的一个或多个程序包存在漏洞，但供应商表示不会修补此漏洞。描述
Linux/Unix 主机中安装的一个或多个程序包受到一个漏洞影响，而供应商没有提供补丁程序。- 在 Linux 内核中，已解决以下漏洞： powerpc/set_memory: Avoid spinlock recursion in change_page_attr() Commit 1f9ad21c3b38 (powerpc/mm: Implement set_memory() routines) included a spin_lock() to change_page_attr() in order to safely perform the three step operations. But then commit 9f7853d7609d (powerpc/mm: Fix set_memory_*() against concurrent accesses) modify it to use pte_update() and do the operation safely against concurrent access. In the meantime, Maxime reported some spinlock recursion. [ 15.351649] BUG: spinlock recursion on CPU#0, kworker/0:2/217 [ 15.357540] lock:
init_mm+0x3c/0x420, .magic: dead4ead, .owner: kworker/0:2/217, .owner_cpu: 0 [ 15.366563] CPU: 0 PID: 217 Comm: kworker/0:2 Not tainted 5.15.0+ #523 [ 15.373350] Workqueue: events do_free_init [ 15.377615] Call Trace: [ 15.380232] [e4105ac0] [800946a4] do_raw_spin_lock+0xf8/0x120 (unreliable) [ 15.387340] [e4105ae0] [8001f4ec] change_page_attr+0x40/0x1d4 [ 15.393413] [e4105b10] [801424e0]
__apply_to_page_range+0x164/0x310 [ 15.400009] [e4105b60] [80169620] free_pcp_prepare+0x1e4/0x4a0 [15.406045] [e4105ba0] [8016c5a0] free_unref_page+0x40/0x2b8 [ 15.411979] [e4105be0] [8018724c] kasan_depopulate_vmalloc_pte+0x6c/0x94 [ 15.418989] [e4105c00] [801424e0]
__apply_to_page_range+0x164/0x310 [ 15.425451] [e4105c50] [80187834] kasan_release_vmalloc+0xbc/0x134 [15.431898] [e4105c70] [8015f7a8] __purge_vmap_area_lazy+0x4e4/0xdd8 [ 15.438560] [e4105d30] [80160d10]
_vm_unmap_aliases.part.0+0x17c/0x24c [ 15.445283] [e4105d60] [801642d0] __vunmap+0x2f0/0x5c8 [ 15.450684] [e4105db0] [800e32d0] do_free_init+0x68/0x94 [ 15.456181] [e4105dd0] [8005d094] process_one_work+0x4bc/0x7b8 [ 15.462283] [e4105e90] [8005d614] worker_thread+0x284/0x6e8 [ 15.468227] [e4105f00] [8006aaec] kthread+0x1f0/0x210 [ 15.473489] [e4105f40] [80017148] ret_from_kernel_thread+0x14/0x1c Remove the read / modify / write sequence to make the operation atomic and remove the spin_lock() in change_page_attr(). To do the operation atomically, we can't use pte modification helpers anymore. Because all platforms have different combination of bits, it is not easy to use those bits directly. But all have the _PAGE_KERNEL_{RO/ROX/RW/RWX} set of flags. All we need it to compare two sets to know which bits are set or cleared. For instance, by comparing _PAGE_KERNEL_ROX and
_PAGE_KERNEL_RO you know which bit gets cleared and which bit get set when changing exec permission.
(CVE-2021-47632)
请注意，Nessus 依赖供应商报告的程序包是否存在进行判断。
解决方案
目前尚未有任何已知的解决方案。插件详情
严重性: High
ID: 230092
文件名: unpatched_CVE_2021_47632.nasl
版本: 1.1
类型: local
代理: unix
系列: Misc.
发布时间: 2025/3/5
最近更新时间: 2025/3/5
支持的传感器: Nessus Agent, Nessus
风险信息
VPR
风险因素: Medium
分数: 4.4
CVSS v2
风险因素: Medium
基本分数: 5.6
时间分数: 4.1
矢量: CVSS2#AV:L/AC:L/Au:N/C:N/I:P/A:C
CVSS 分数来源: CVE-2021-47632
CVSS v3
风险因素: High
基本分数: 7.1
时间分数: 6.2
矢量: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
时间矢量: CVSS:3.0/E:U/RL:O/RC:C
漏洞信息
必需的 KB 项: Host/local_checks_enabled, Host/cpu, global_settings/vendor_unpatched
易利用性: No known exploits are available
漏洞发布日期: 2025/2/26
参考资料信息
CVE: CVE-2021-47632