CVE-2023-2598 内核提权漏洞分析与利用指南<\/h1>

漏洞概述<\/h2>
CVE-2023-2598 是一个 Linux 内核中的本地权限提升漏洞，影响 io_uring 子系统。该漏洞允许本地攻击者通过精心构造的请求获取 root 权限，危害性较高。<\/p>

受影响版本<\/h2>

Linux 内核 5.12 至 5.15.x<\/li>

部分 5.16 和 5.17 版本也可能受影响<\/li> <\/ul>

环境搭建<\/h2>

测试环境准备<\/h3>

安装受影响内核版本：<\/p>

sudo apt install linux-image-5.15.0-76-generic
<\/code><\/pre>
<\/li>

验证内核版本：<\/p>
uname -r
<\/code><\/pre>
<\/li>

安装编译工具链：<\/p>
sudo apt install build-essential libssl-dev bison flex
<\/code><\/pre>
<\/li>
<\/ol>
漏洞原理<\/h2>
io_uring 子系统简介<\/h3>
io_uring 是 Linux 内核提供的高性能异步 I\/O 接口，通过环形队列实现用户空间与内核空间的高效通信。<\/p>
漏洞根源<\/h3>
漏洞存在于 io_sqe_buffers_register()<\/code> 和 io_sqe_buffer_register()<\/code> 函数中，由于对 folio 结构处理不当，导致内存管理错误。<\/p>
关键技术点<\/h3>

folio 结构<\/strong>：Linux 内核 5.12 引入的新内存页管理结构<\/li>
注册缓冲区<\/strong>：io_uring 允许用户空间注册 I\/O 缓冲区<\/li>
引用计数错误<\/strong>：漏洞导致引用计数不正确，可能造成 use-after-free<\/li>
<\/ol>
漏洞分析<\/h2>
关键函数分析<\/h3>
io_sqe_buffers_register()<\/h4>
static<\/span> int<\/span> io_sqe_buffers_register<\/span>(struct<\/span> io_ring_ctx *<\/span>ctx, void<\/span> __user *<\/span>arg,
<\/span><\/span>				   unsigned<\/span> nr_args)
<\/span><\/span>{
<\/span><\/span>	struct<\/span> page *<\/span>pages;
<\/span><\/span>	int<\/span> ret, i;
<\/span><\/span>	struct<\/span> io_buffer *<\/span>bufs;
<\/span><\/span>	
<\/span><\/span>	bufs =<\/span> kcalloc(nr_args, sizeof<\/span>(*<\/span>bufs), GFP_KERNEL);
<\/span><\/span>	[...]
<\/span><\/span>	for<\/span> (i =<\/span> 0<\/span>; i <<\/span> nr_args; i++<\/span>) {
<\/span><\/span>		ret =<\/span> io_sqe_buffer_register(ctx, &<\/span>bufs[i], &<\/span>pages);
<\/span><\/span>		if<\/span> (ret)
<\/span><\/span>			break<\/span>;
<\/span><\/span>	}
<\/span><\/span>	[...]
<\/span><\/span>}
<\/span><\/span><\/code><\/pre>io_sqe_buffer_register()<\/h4>
static<\/span> int<\/span> io_sqe_buffer_register<\/span>(struct<\/span> io_ring_ctx *<\/span>ctx, struct<\/span> io_buffer *<\/span>buf,
<\/span><\/span>				  struct<\/span> page **<\/span>pages)
<\/span><\/span>{
<\/span><\/span>	struct<\/span> page *<\/span>page;
<\/span><\/span>	[...]
<\/span><\/span>	page =<\/span> buf-><\/span>page;
<\/span><\/span>	if<\/span> (!<\/span>page) {
<\/span><\/span>		page =<\/span> alloc_page(GFP_KERNEL);
<\/span><\/span>		if<\/span> (!<\/span>page)
<\/span><\/span>			return<\/span> -<\/span>ENOMEM;
<\/span><\/span>		buf-><\/span>page =<\/span> page;
<\/span><\/span>	}
<\/span><\/span>	[...]
<\/span><\/span>	\/\/ 漏洞点：缺少对folio引用计数的正确处理
<\/span><\/span><\/span><\/span>	folio_get(page_folio(page));
<\/span><\/span>	[...]
<\/span><\/span>}
<\/span><\/span><\/code><\/pre>漏洞利用<\/h2>
利用思路<\/h3>

通过 io_uring 注册多个缓冲区<\/li>
触发引用计数错误<\/li>
制造 use-after-free 条件<\/li>
利用释放的内存页进行权限提升<\/li>
<\/ol>
EXP 复现步骤<\/h3>


编译并加载漏洞利用代码：<\/p>
gcc exploit.c -o exploit
<\/span><\/span><\/code><\/pre><\/li>

执行利用程序：<\/p>
.\/exploit
<\/span><\/span><\/code><\/pre><\/li>

验证提权结果：<\/p>
id
<\/span><\/span><\/code><\/pre><\/li>
<\/ol>
关键利用代码片段<\/h3>
struct<\/span> io_uring_params p =<\/span> {
<\/span><\/span>    .sq_entries =<\/span> 1<\/span>,
<\/span><\/span>    .cq_entries =<\/span> 1<\/span>,
<\/span><\/span>    .flags =<\/span> IORING_SETUP_SQE128,
<\/span><\/span>};
<\/span><\/span>
<\/span><\/span>int<\/span> fd =<\/span> io_uring_setup(1<\/span>, &<\/span>p);
<\/span><\/span>[...]
<\/span><\/span>struct<\/span> io_uring_sqe *<\/span>sqe =<\/span> io_uring_get_sqe(&<\/span>ring);
<\/span><\/span>io_uring_prep_provide_buffers(sqe, bufs, 1<\/span>, 1<\/span>, group_id, 0<\/span>);
<\/span><\/span>[...]
<\/span><\/span><\/code><\/pre>防护措施<\/h2>
临时缓解方案<\/h3>


禁用 io_uring：<\/p>
echo 0<\/span> > \/proc\/sys\/kernel\/io_uring_enabled
<\/span><\/span><\/code><\/pre><\/li>

限制非特权用户使用：<\/p>
sysctl -w kernel.io_uring_disabled=<\/span>1<\/span>
<\/span><\/span><\/code><\/pre><\/li>
<\/ol>
长期解决方案<\/h3>
升级到已修复的内核版本：<\/p>
sudo apt update &&<\/span> sudo apt upgrade linux-image-$(<\/span>uname -r)<\/span>
<\/span><\/span><\/code><\/pre>参考资源<\/h2>

官方漏洞公告：https:\/\/cve.mitre.org\/cgi-bin\/cvename.cgi?name=CVE-2023-2598<\/li>
Linux 内核补丁：https:\/\/git.kernel.org\/pub\/scm\/linux\/kernel\/git\/torvalds\/linux.git\/commit\/?id=xxxxxx<\/li>
详细技术分析：https:\/\/securityblog.example\/cve-2023-2598-deep-dive<\/li>
<\/ol>
附录<\/h2>
完整 EXP 代码<\/h3>
[此处应包含完整的漏洞利用代码，但由于安全考虑，建议仅用于研究目的]<\/p>
调试技巧<\/h3>


使用 crash<\/code> 工具分析内核转储<\/p>
<\/li>

启用内核调试符号：<\/p>
echo 1<\/span> > \/proc\/sys\/kernel\/sysrq
<\/span><\/span>echo g > \/proc\/sysrq-trigger
<\/span><\/span><\/code><\/pre><\/li>

使用 dmesg<\/code> 查看内核日志：<\/p>
dmesg | grep io_uring
<\/span><\/span><\/code><\/pre><\/li>
<\/ol>

CVE-2023-2598 内核提权漏洞分析与利用指南<\/h1>

漏洞概述<\/h2> CVE-2023-2598 是一个 Linux 内核中的本地权限提升漏洞，影响 io_uring 子系统。该漏洞允许本地攻击者通过精心构造的请求获取 root 权限，危害性较高。<\/p>

环境搭建<\/h2>

漏洞原理<\/h2>

io_uring 子系统简介<\/h3> io_uring 是 Linux 内核提供的高性能异步 I\/O 接口，通过环形队列实现用户空间与内核空间的高效通信。<\/p>

漏洞根源<\/h3> 漏洞存在于 io_sqe_buffers_register()<\/code> 和 io_sqe_buffer_register()<\/code> 函数中，由于对 folio 结构处理不当，导致内存管理错误。<\/p>

漏洞分析<\/h2>

关键函数分析<\/h3>

漏洞利用<\/h2>

防护措施<\/h2>

附录<\/h2>

完整 EXP 代码<\/h3> [此处应包含完整的漏洞利用代码，但由于安全考虑，建议仅用于研究目的]<\/p>

漏洞概述<\/h2>
CVE-2023-2598 是一个 Linux 内核中的本地权限提升漏洞，影响 io_uring 子系统。该漏洞允许本地攻击者通过精心构造的请求获取 root 权限，危害性较高。<\/p>

io_uring 子系统简介<\/h3>
io_uring 是 Linux 内核提供的高性能异步 I\/O 接口，通过环形队列实现用户空间与内核空间的高效通信。<\/p>

漏洞根源<\/h3>
漏洞存在于 `io_sqe_buffers_register()<\/code> 和 io_sqe_buffer_register()<\/code> 函数中，由于对 folio 结构处理不当，导致内存管理错误。<\/p>`

完整 EXP 代码<\/h3>
[此处应包含完整的漏洞利用代码，但由于安全考虑，建议仅用于研究目的]<\/p>