{"id":35458,"date":"2025-03-19T09:56:13","date_gmt":"2025-03-19T01:56:13","guid":{"rendered":"https:\/\/www.yunshan.net\/blog\/?p=35458"},"modified":"2025-03-19T09:56:13","modified_gmt":"2025-03-19T01:56:13","slug":"%e5%a6%82%e4%bd%95%e4%bd%bf%e7%94%a8ebpf%e8%bf%9b%e8%a1%8c%e5%86%85%e6%a0%b8%e6%bc%8f%e6%b4%9e%e6%a3%80%e6%b5%8b%e5%92%8c%e9%98%b2%e6%8a%a4%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/www.yunshan.net\/blog\/archives\/35458.html","title":{"rendered":"\u5982\u4f55\u4f7f\u7528eBPF\u8fdb\u884c\u5185\u6838\u6f0f\u6d1e\u68c0\u6d4b\u548c\u9632\u62a4\uff1f"},"content":{"rendered":"<p style=\"text-align: center;\">\n<p><img decoding=\"async\" src=\"https:\/\/www.yunshan.net\/blog\/wp-content\/uploads\/2025\/03\/cPMEdc.jpg\" alt=\"\u5982\u4f55\u4f7f\u7528eBPF\u8fdb\u884c\u5185\u6838\u6f0f\u6d1e\u68c0\u6d4b\u548c\u9632\u62a4\uff1f\" ><\/p>\n<\/p>\n<p><strong>\u524d\u8a00<\/strong><br \/>\n\u5728\u6570\u5b57\u5316\u6d6a\u6f6e\u5e2d\u5377\u5168\u7403\u7684\u4eca\u5929\uff0c\u64cd\u4f5c\u7cfb\u7edf\u5185\u6838\u4f5c\u4e3a\u8ba1\u7b97\u8bbe\u5907\u7684&rdquo;\u5fc3\u810f&rdquo;\uff0c\u627f\u8f7d\u7740\u8d44\u6e90\u8c03\u5ea6\u3001\u786c\u4ef6\u4ea4\u4e92\u3001\u5b89\u5168\u63a7\u5236\u7b49\u6838\u5fc3\u529f\u80fd\u3002\u7136\u800c\uff0c\u5185\u6838\u5c42\u7684\u9ad8\u6743\u9650\u7279\u6027\u4f7f\u5176\u6210\u4e3a\u7f51\u7edc\u653b\u51fb\u7684\u7126\u70b9\u2014\u2014\u4e00\u4e2a\u5fae\u5c0f\u7684\u6f0f\u6d1e\u53ef\u80fd\u5f15\u53d1\u7cfb\u7edf\u5d29\u6e83\u3001\u6570\u636e\u6cc4\u9732\u751a\u81f3\u4f9b\u5e94\u94fe\u653b\u51fb\u3002\u4f20\u7edf\u7684\u6f0f\u6d1e\u68c0\u6d4b\u5de5\u5177\u5e38\u56e0\u6027\u80fd\u635f\u8017\u5927\u3001\u7075\u6d3b\u6027\u4e0d\u8db3\u800c\u96be\u4ee5\u5e94\u5bf9\u590d\u6742\u7684\u5185\u6838\u5a01\u80c1\u3002<strong><a href=\"https:\/\/www.yunshan.net\/\"   target=\"_blank\" style=\"color:blue\">eBPF<\/a><\/strong>\uff08Extended Berkeley Packet Filter\uff09\u6280\u672f\u51ed\u501f\u5176<strong>\u5b89\u5168\u6c99\u7bb1\u673a\u5236<\/strong>\u548c<strong>\u52a8\u6001\u8ffd\u8e2a\u80fd\u529b<\/strong>\uff0c\u6b63\u5728\u91cd\u65b0\u5b9a\u4e49\u5185\u6838\u5b89\u5168\u7684\u53ef\u80fd\u6027\u3002\u672c\u6587\u5c06\u6df1\u5165\u63a2\u8ba8\u5982\u4f55\u5229\u7528<a href=\"https:\/\/www.yunshan.net\/\"   target=\"_blank\" style=\"color:blue\">eBPF<\/a>\u6784\u5efa\u8f7b\u91cf\u7ea7\u3001\u5b9e\u65f6\u7684\u5185\u6838\u9632\u62a4\u4f53\u7cfb\uff0c\u4e3a\u5f00\u53d1\u8005\u4e0e\u5b89\u5168\u5de5\u7a0b\u5e08\u63d0\u4f9b\u53ef\u843d\u5730\u7684\u89e3\u51b3\u65b9\u6848\u3002<\/p>\n<hr>\n<h3 id=\"\u4e00-ebpf\u6280\u672f\u5185\u6838\u5b89\u5168\u7684\u6838\u5fc3\u4f18\u52bf\"><strong>\u4e00\u3001eBPF\u6280\u672f\u5185\u6838\u5b89\u5168\u7684\u6838\u5fc3\u4f18\u52bf<\/strong><\/h3>\n<p>eBPF\u6700\u521d\u8bbe\u8ba1\u7528\u4e8e\u7f51\u7edc\u6570\u636e\u5305\u8fc7\u6ee4\uff0c\u7ecf\u8fc7\u591a\u5e74\u6f14\u8fdb\uff0c\u5df2\u53d1\u5c55\u4e3a\u80fd\u591f<strong>\u5728\u5185\u6838\u7a7a\u95f4\u5b89\u5168\u6267\u884c\u81ea\u5b9a\u4e49\u7a0b\u5e8f<\/strong>\u7684\u901a\u7528\u6280\u672f\u3002\u5176\u72ec\u7279\u4f18\u52bf\u4f53\u73b0\u5728\u4e09\u4e2a\u65b9\u9762\uff1a<\/p>\n<ol>\n<li><strong>\u52a8\u6001\u6ce8\u5165\u4e0e\u96f6\u91cd\u542f<\/strong>\uff1aeBPF\u7a0b\u5e8f\u53ef\u5728\u8fd0\u884c\u65f6\u52a0\u8f7d\u5230\u5185\u6838\uff0c\u65e0\u9700\u4fee\u6539\u5185\u6838\u6e90\u7801\u6216\u91cd\u542f\u7cfb\u7edf\uff0c\u663e\u8457\u964d\u4f4e\u5b89\u5168\u7b56\u7565\u90e8\u7f72\u6210\u672c\u3002\n<\/li>\n<li><strong>\u5b89\u5168\u9a8c\u8bc1\u673a\u5236<\/strong>\uff1a\u5185\u6838\u5185\u7f6e\u7684\u9a8c\u8bc1\u5668\u4f1a<strong>\u9759\u6001\u5206\u6790eBPF\u5b57\u8282\u7801<\/strong>\uff0c\u786e\u4fdd\u5176\u4e0d\u4f1a\u5bfc\u81f4\u6b7b\u5faa\u73af\u3001\u5185\u5b58\u8d8a\u754c\u7b49\u98ce\u9669\uff0c\u4ece\u6e90\u5934\u963b\u65ad\u6076\u610f\u4ee3\u7801\u3002\n<\/li>\n<li><strong>\u4f4e\u6027\u80fd\u635f\u8017<\/strong>\uff1a\u76f8\u8f83\u4e8e\u4f20\u7edf\u5185\u6838\u6a21\u5757\uff0ceBPF\u7a0b\u5e8f\u901a\u8fc7JIT\uff08\u5373\u65f6\u7f16\u8bd1\uff09\u6280\u672f\u5c06\u5b57\u8282\u7801\u8f6c\u6362\u4e3a\u672c\u5730\u6307\u4ee4\uff0c\u6548\u7387\u635f\u5931\u901a\u5e38\u4f4e\u4e8e5%\u3002\n<\/li>\n<\/ol>\n<p><em>\u4ee5CVE-2021-4034\uff08Polkit\u6743\u9650\u63d0\u5347\u6f0f\u6d1e\uff09\u4e3a\u4f8b\uff0c\u653b\u51fb\u8005\u901a\u8fc7\u73af\u5883\u53d8\u91cf\u6ce8\u5165\u5b9e\u73b0\u63d0\u6743\u3002\u82e5\u91c7\u7528eBPF\u5b9e\u65f6\u76d1\u63a7<code>execve<\/code>\u7cfb\u7edf\u8c03\u7528\u7684\u53c2\u6570\uff0c\u53ef\u7acb\u5373\u963b\u65ad\u5f02\u5e38\u8fdb\u7a0b\u94fe\uff0c\u800c\u4f20\u7edf\u57fa\u4e8e\u65e5\u5fd7\u5206\u6790\u7684\u65b9\u6cd5\u5f80\u5f80\u5b58\u5728\u6570\u5c0f\u65f6\u6ede\u540e\u3002<\/em><\/p>\n<hr>\n<h3 id=\"\u4e8c-\u6784\u5efa\u5185\u6838\u6f0f\u6d1e\u68c0\u6d4b\u7684\u4e09\u5c42ebpf\u6a21\u578b\"><strong>\u4e8c\u3001\u6784\u5efa\u5185\u6838\u6f0f\u6d1e\u68c0\u6d4b\u7684\u4e09\u5c42eBPF\u6a21\u578b<\/strong><\/h3>\n<h4 id=\"1-\u7cfb\u7edf\u8c03\u7528\u76d1\u63a7\u5c42\"><strong>1. \u7cfb\u7edf\u8c03\u7528\u76d1\u63a7\u5c42<\/strong><\/h4>\n<p>\u901a\u8fc7\u6302\u94a9<code>sys_enter<\/code>\/<code>sys_exit<\/code>\u7b49\u8ddf\u8e2a\u70b9\uff0ceBPF\u7a0b\u5e8f\u80fd\u6355\u83b7\u6240\u6709\u7528\u6237\u6001\u4e0e\u5185\u6838\u6001\u7684\u4ea4\u4e92\u884c\u4e3a\u3002\u4f8b\u5982\uff1a<\/p>\n<ul>\n<li><strong>\u68c0\u6d4b\u7f13\u51b2\u533a\u6ea2\u51fa<\/strong>\uff1a\u76d1\u63a7<code>copy_from_user<\/code>\u51fd\u6570\u7684<code>size<\/code>\u53c2\u6570\u662f\u5426\u8d85\u8fc7\u76ee\u6807\u7f13\u51b2\u533a\u957f\u5ea6\u3002\n<\/li>\n<li><strong>\u8bc6\u522b\u5f02\u5e38\u6743\u9650\u64cd\u4f5c<\/strong>\uff1a\u8bb0\u5f55\u975e\u7279\u6743\u8fdb\u7a0b\u8c03\u7528<code>capset<\/code>\u6216<code>ioctl<\/code>\u7684\u654f\u611f\u6307\u4ee4\u3002\n<\/li>\n<\/ul>\n<pre><code class=\"language-c\">\/\/ \u793a\u4f8b\uff1a\u68c0\u6d4bexecve\u8c03\u7528\u7684\u975e\u6cd5\u53c2\u6570  \r\nSEC(&quot;tracepoint\/syscalls\/sys_enter_execve&quot;)  \r\nint handle_execve(struct trace_event_raw_sys_enter *ctx) {  \r\nchar filename[256];  \r\nbpf_probe_read_user_str(filename, sizeof(filename), (void *)ctx-&gt;args[0]);  \r\nif (str_contains(filename, &quot;..\/&quot;)) { \/\/ \u68c0\u6d4b\u8def\u5f84\u7a7f\u8d8a\u7279\u5f81  \r\nbpf_printk(&quot;Suspicious execve: %s&quot;, filename);  \r\nblock_process();  \r\n}  \r\nreturn 0;  \r\n}  \r\n<\/code><\/pre>\n<h4 id=\"2-\u5185\u6838\u51fd\u6570\u5ba1\u8ba1\u5c42\"><strong>2. \u5185\u6838\u51fd\u6570\u5ba1\u8ba1\u5c42<\/strong><\/h4>\n<p>\u501f\u52a9<strong>kprobe\/uprobe<\/strong>\uff0ceBPF\u80fd\u591f\u6df1\u5165\u5185\u6838\u51fd\u6570\u5185\u90e8\uff0c\u5ba1\u8ba1\u5185\u5b58\u5206\u914d\u3001\u9501\u72b6\u6001\u7b49\u5173\u952e\u64cd\u4f5c\uff1a<\/p>\n<ul>\n<li><strong>\u5185\u5b58\u5b89\u5168\u68c0\u6d4b<\/strong>\uff1a\u8ffd\u8e2a<code>kmalloc<\/code>\/<code>kfree<\/code>\u8c03\u7528\u5e8f\u5217\uff0c\u8bc6\u522b\u91cd\u590d\u91ca\u653e\uff08Double Free\uff09\u6216\u91ca\u653e\u540e\u4f7f\u7528\uff08UAF\uff09\u6f0f\u6d1e\u3002\n<\/li>\n<li><strong>\u6570\u636e\u7ade\u4e89\u5206\u6790<\/strong>\uff1a\u76d1\u63a7\u81ea\u65cb\u9501\uff08spinlock\uff09\u7684\u6301\u6709\u65f6\u95f4\uff0c\u53d1\u73b0\u672a\u6b63\u786e\u91ca\u653e\u9501\u7684\u4ee3\u7801\u8def\u5f84\u3002\n<\/li>\n<\/ul>\n<h4 id=\"3-\u884c\u4e3a\u6a21\u5f0f\u5173\u8054\u5c42\"><strong>3. \u884c\u4e3a\u6a21\u5f0f\u5173\u8054\u5c42<\/strong><\/h4>\n<p>\u5c06eBPF\u4e8b\u4ef6\u4e0e\u7528\u6237\u6001\u65e5\u5fd7\u7ed3\u5408\uff0c\u5229\u7528\u673a\u5668\u5b66\u4e60\u6a21\u578b\u8bc6\u522b\u653b\u51fb\u94fe\u3002\u4f8b\u5982\uff0c\u7ed3\u5408<strong>Falco<\/strong>\u7b49\u5de5\u5177\uff0c\u53ef\u6784\u5efa\u89c4\u5219\uff1a<\/p>\n<ul>\n<li>\u82e5\u67d0\u8fdb\u7a0b\u572810\u79d2\u5185\u8fde\u7eed\u89e6\u53d15\u6b21\u4ee5\u4e0a\u5931\u8d25\u7684<code>open<\/code>\u8c03\u7528\uff0c\u4e14\u968f\u540e\u5c1d\u8bd5\u52a0\u8f7d\u5185\u6838\u6a21\u5757\uff0c\u5219\u5224\u5b9a\u4e3a\u53ef\u7591\u63d0\u6743\u884c\u4e3a\u3002\n<\/li>\n<\/ul>\n<hr>\n<h3 id=\"\u4e09-ebpf\u9a71\u52a8\u7684\u5b9e\u65f6\u9632\u62a4\u673a\u5236\"><strong>\u4e09\u3001eBPF\u9a71\u52a8\u7684\u5b9e\u65f6\u9632\u62a4\u673a\u5236<\/strong><\/h3>\n<h4 id=\"1-\u5b9e\u65f6\u62e6\u622a\u6076\u610f\u64cd\u4f5c\"><strong>1. \u5b9e\u65f6\u62e6\u622a\u6076\u610f\u64cd\u4f5c<\/strong><\/h4>\n<p>eBPF\u7a0b\u5e8f\u4e0d\u4ec5\u80fd\u68c0\u6d4b\u6f0f\u6d1e\uff0c\u8fd8\u80fd\u901a\u8fc7\u4fee\u6539\u8fd4\u56de\u503c\u6216\u4e22\u5f03\u6570\u636e\u5305\u76f4\u63a5\u963b\u65ad\u653b\u51fb\u3002\u4f8b\u5982\uff1a<\/p>\n<ul>\n<li><strong>\u62e6\u622a\u975e\u6cd5\u5185\u5b58\u8bbf\u95ee<\/strong>\uff1a\u5728<code>do_page_fault<\/code>\u51fd\u6570\u4e2d\u6ce8\u5165\u68c0\u67e5\u903b\u8f91\uff0c\u82e5\u7f3a\u9875\u5730\u5740\u5c5e\u4e8e\u53d7\u4fdd\u62a4\u533a\u57df\uff0c\u5219\u8fd4\u56de<code>EFAULT<\/code>\u9519\u8bef\u3002\n<\/li>\n<li><strong>\u8fc7\u6ee4\u6076\u610f\u7f51\u7edc\u6d41\u91cf<\/strong>\uff1a\u7ed3\u5408XDP\uff08eXpress Data Path\uff09\u6280\u672f\uff0c\u5728\u7f51\u5361\u9a71\u52a8\u5c42\u4e22\u5f03\u5305\u542bShellcode\u7279\u5f81\u7684TCP\u62a5\u6587\u3002\n<\/li>\n<\/ul>\n<h4 id=\"2-\u6700\u5c0f\u5316\u6743\u9650\u63a7\u5236\"><strong>2. \u6700\u5c0f\u5316\u6743\u9650\u63a7\u5236<\/strong><\/h4>\n<p>\u901a\u8fc7<strong>LSM\uff08Linux Security Module\uff09\u6302\u94a9\u70b9<\/strong>\uff0ceBPF\u53ef\u5b9e\u73b0\u7ec6\u7c92\u5ea6\u6743\u9650\u7b56\u7565\uff1a<\/p>\n<pre><code class=\"language-c\">SEC(&quot;lsm\/file_open&quot;)  \r\nint BPF_PROG(file_open, struct file *file) {  \r\nu32 uid = bpf_get_current_uid_gid() &amp; 0xFFFFFFFF;  \r\nif (uid != 0 &amp;&amp; file-&gt;f_path.dentry == sensitive_file) {  \r\nreturn -EPERM; \/\/ \u7981\u6b62\u975eroot\u7528\u6237\u8bbf\u95ee\u654f\u611f\u6587\u4ef6  \r\n}  \r\nreturn 0;  \r\n}  \r\n<\/code><\/pre>\n<hr>\n<h3 id=\"\u56db-\u6311\u6218\u4e0e\u6700\u4f73\u5b9e\u8df5\"><strong>\u56db\u3001\u6311\u6218\u4e0e\u6700\u4f73\u5b9e\u8df5<\/strong><\/h3>\n<h4 id=\"1-\u517c\u5bb9\u6027\u95ee\u9898\"><strong>1. \u517c\u5bb9\u6027\u95ee\u9898<\/strong><\/h4>\n<p>\u4e0d\u540c\u5185\u6838\u7248\u672c\u7684eBPF\u7279\u6027\u652f\u6301\u5b58\u5728\u5dee\u5f02\u3002\u89e3\u51b3\u65b9\u6848\u5305\u62ec\uff1a<\/p>\n<ul>\n<li>\u4f7f\u7528<strong>libbpf<\/strong>\u5e93\u81ea\u52a8\u9002\u914d\u5185\u6838ABI\u3002\n<\/li>\n<li>\u901a\u8fc7<code>CO-RE\uff08Compile Once \u2013 Run Everywhere\uff09<\/code>\u6280\u672f\u6d88\u9664\u7ed3\u6784\u4f53\u504f\u79fb\u4f9d\u8d56\u3002\n<\/li>\n<\/ul>\n<h4 id=\"2-\u6027\u80fd\u8c03\u4f18\"><strong>2. \u6027\u80fd\u8c03\u4f18<\/strong><\/h4>\n<ul>\n<li><strong>\u51cf\u5c11Map\u67e5\u8be2\u9891\u7387<\/strong>\uff1a\u5728\u7528\u6237\u6001\u7ef4\u62a4\u7f13\u5b58\u72b6\u6001\uff0c\u4ec5\u5728\u5185\u6838\u4e8b\u4ef6\u89e6\u53d1\u65f6\u66f4\u65b0\u3002\n<\/li>\n<li><strong>\u907f\u514d\u5faa\u73af\u4e0e\u5168\u5c40\u53d8\u91cf<\/strong>\uff1a\u4f18\u5148\u4f7f\u7528<code>perf_event<\/code>\u8f93\u51fa\u6570\u636e\uff0c\u800c\u975e\u9891\u7e41\u7684<code>bpf_printk<\/code>\u3002\n<\/li>\n<\/ul>\n<h4 id=\"3-\u5b89\u5168\u52a0\u56fa\"><strong>3. \u5b89\u5168\u52a0\u56fa<\/strong><\/h4>\n<ul>\n<li><strong>\u7981\u7528\u975e\u5fc5\u8981\u6743\u9650<\/strong>\uff1a\u52a0\u8f7deBPF\u7a0b\u5e8f\u65f6\u8bbe\u7f6e<code>CAP_BPF<\/code>\u800c\u975e<code>CAP_SYS_ADMIN<\/code>\u3002\n<\/li>\n<li><strong>\u7b7e\u540d\u9a8c\u8bc1<\/strong>\uff1a\u5229\u7528\u5185\u6838\u7684BPF\u7b7e\u540d\u673a\u5236\uff0c\u786e\u4fdd\u4ec5\u5141\u8bb8\u53ef\u4fe1\u7a0b\u5e8f\u8fd0\u884c\u3002\n<\/li>\n<\/ul>\n<hr>\n<h3 id=\"\u4e94-\u5b9e\u6218\u6848\u4f8b-\u68c0\u6d4bcve-2022-0847-dirty-pipe-\u6f0f\u6d1e\"><strong>\u4e94\u3001\u5b9e\u6218\u6848\u4f8b\uff1a\u68c0\u6d4bCVE-2022-0847 &ldquo;Dirty Pipe&rdquo;\u6f0f\u6d1e<\/strong><\/h3>\n<p>\u8be5\u6f0f\u6d1e\u5229\u7528\u672a\u521d\u59cb\u5316\u7684<code>pipe_buffer<\/code>\u7ed3\u6784\u4f53\u7be1\u6539\u53ea\u8bfb\u6587\u4ef6\u3002\u57fa\u4e8eeBPF\u7684\u68c0\u6d4b\u65b9\u6848\u53ef\u8bbe\u8ba1\u4e3a\uff1a<\/p>\n<ol>\n<li>\u6302\u94a9<code>splice<\/code>\u7cfb\u7edf\u8c03\u7528\uff0c\u68c0\u67e5<code>flags<\/code>\u53c2\u6570\u662f\u5426\u5305\u542b<code>SPLICE_F_GIFT<\/code>\u3002\n<\/li>\n<li>\u76d1\u63a7<code>pipe_write<\/code>\u51fd\u6570\u4e2d\u5bf9<code>page-&gt;flags<\/code>\u7684\u4fee\u6539\u64cd\u4f5c\u3002\n<\/li>\n<li>\u82e5\u68c0\u6d4b\u5230\u975e\u7279\u6743\u8fdb\u7a0b\u5c1d\u8bd5\u5199\u5165\u53ea\u8bfb\u6587\u4ef6\uff0c\u7acb\u5373\u7ec8\u6b62\u8fdb\u7a0b\u5e76\u544a\u8b66\u3002\n<\/li>\n<\/ol>\n<p>&rdquo;`bash<\/p>\n<h1 id=\"\u4f7f\u7528bpftrace\u5feb\u901f\u9a8c\u8bc1\">\u4f7f\u7528bpftrace\u5feb\u901f\u9a8c\u8bc1<\/h1>\n<p>bpftrace -e &lsquo;tracepoint:<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u524d\u8a00 \u5728\u6570\u5b57\u5316\u6d6a\u6f6e\u5e2d\u5377\u5168\u7403\u7684\u4eca\u5929\uff0c\u64cd\u4f5c\u7cfb\u7edf\u5185\u6838\u4f5c\u4e3a\u8ba1\u7b97\u8bbe\u5907\u7684&rdquo;\u5fc3\u810f&rdquo;\uff0c\u627f\u8f7d\u7740\u8d44\u6e90\u8c03\u5ea6\u3001\u786c\u4ef6\u4ea4\u4e92\u3001\u5b89\u5168\u63a7\u5236\u7b49\u6838\u5fc3\u529f\u80fd\u3002\u7136\u800c\uff0c\u5185\u6838\u5c42\u7684\u9ad8\u6743\u9650\u7279\u6027\u4f7f\u5176\u6210\u4e3a\u7f51\u7edc\u653b\u51fb\u7684\u7126\u70b9\u2014\u2014\u4e00\u4e2a\u5fae\u5c0f\u7684\u6f0f\u6d1e\u53ef\u80fd\u5f15\u53d1\u7cfb\u7edf\u5d29\u6e83\u3001\u6570\u636e\u6cc4\u9732\u751a\u81f3\u4f9b\u5e94\u94fe\u653b\u51fb\u3002\u4f20\u7edf\u7684\u6f0f\u6d1e\u68c0\u6d4b\u5de5\u5177\u5e38\u56e0\u6027\u80fd\u635f\u8017\u5927\u3001\u7075\u6d3b\u6027\u4e0d\u8db3\u800c\u96be\u4ee5\u5e94\u5bf9\u590d\u6742\u7684\u5185\u6838\u5a01\u80c1\u3002eBPF\uff08Extended Berkeley Packet Filter\uff09\u6280\u672f\u51ed\u501f\u5176\u5b89\u5168\u6c99\u7bb1\u673a\u5236\u548c\u52a8\u6001\u8ffd\u8e2a\u80fd\u529b\uff0c\u6b63\u5728\u91cd\u65b0\u5b9a\u4e49\u5185\u6838\u5b89\u5168\u7684\u53ef\u80fd\u6027\u3002\u672c\u6587\u5c06\u6df1\u5165\u63a2\u8ba8\u5982\u4f55\u5229\u7528eBPF\u6784\u5efa\u8f7b\u91cf\u7ea7\u3001\u5b9e\u65f6\u7684\u5185\u6838\u9632\u62a4\u4f53\u7cfb\uff0c\u4e3a\u5f00\u53d1\u8005\u4e0e\u5b89\u5168\u5de5\u7a0b\u5e08\u63d0\u4f9b\u53ef\u843d\u5730\u7684\u89e3\u51b3\u65b9\u6848\u3002 \u4e00\u3001eBPF\u6280\u672f\u5185\u6838\u5b89\u5168\u7684\u6838\u5fc3\u4f18\u52bf eBPF\u6700\u521d\u8bbe\u8ba1\u7528\u4e8e\u7f51\u7edc\u6570\u636e\u5305\u8fc7\u6ee4\uff0c\u7ecf\u8fc7\u591a\u5e74\u6f14\u8fdb\uff0c\u5df2\u53d1\u5c55\u4e3a\u80fd\u591f\u5728\u5185\u6838\u7a7a\u95f4\u5b89\u5168\u6267\u884c\u81ea\u5b9a\u4e49\u7a0b\u5e8f\u7684\u901a\u7528\u6280\u672f\u3002\u5176\u72ec\u7279\u4f18\u52bf\u4f53\u73b0\u5728\u4e09\u4e2a\u65b9\u9762\uff1a \u52a8\u6001\u6ce8\u5165\u4e0e\u96f6\u91cd\u542f\uff1aeBPF\u7a0b\u5e8f\u53ef\u5728\u8fd0\u884c\u65f6\u52a0\u8f7d\u5230\u5185\u6838\uff0c\u65e0\u9700\u4fee\u6539\u5185\u6838\u6e90\u7801\u6216\u91cd\u542f\u7cfb\u7edf\uff0c\u663e\u8457\u964d\u4f4e\u5b89\u5168\u7b56\u7565\u90e8\u7f72\u6210\u672c\u3002 \u5b89\u5168\u9a8c\u8bc1\u673a\u5236\uff1a\u5185\u6838\u5185\u7f6e\u7684\u9a8c\u8bc1\u5668\u4f1a\u9759\u6001\u5206\u6790eBPF\u5b57\u8282\u7801\uff0c\u786e\u4fdd\u5176\u4e0d\u4f1a\u5bfc\u81f4\u6b7b\u5faa\u73af\u3001\u5185\u5b58\u8d8a\u754c\u7b49\u98ce\u9669\uff0c\u4ece\u6e90\u5934\u963b\u65ad\u6076\u610f\u4ee3\u7801\u3002 \u4f4e\u6027\u80fd\u635f\u8017\uff1a\u76f8\u8f83\u4e8e\u4f20\u7edf\u5185\u6838\u6a21\u5757\uff0ceBPF\u7a0b\u5e8f\u901a\u8fc7JIT\uff08\u5373\u65f6\u7f16\u8bd1\uff09\u6280\u672f\u5c06\u5b57\u8282\u7801\u8f6c\u6362\u4e3a\u672c\u5730\u6307\u4ee4\uff0c\u6548\u7387\u635f\u5931\u901a\u5e38\u4f4e\u4e8e5%\u3002 \u4ee5CVE-2021-4034\uff08Polkit\u6743\u9650\u63d0\u5347\u6f0f\u6d1e\uff09\u4e3a\u4f8b\uff0c\u653b\u51fb\u8005\u901a\u8fc7\u73af\u5883\u53d8\u91cf\u6ce8\u5165\u5b9e\u73b0\u63d0\u6743\u3002\u82e5\u91c7\u7528eBPF\u5b9e\u65f6\u76d1\u63a7execve\u7cfb\u7edf\u8c03\u7528\u7684\u53c2\u6570\uff0c\u53ef\u7acb\u5373\u963b\u65ad\u5f02\u5e38\u8fdb\u7a0b\u94fe\uff0c\u800c\u4f20\u7edf\u57fa\u4e8e\u65e5\u5fd7\u5206\u6790\u7684\u65b9\u6cd5\u5f80\u5f80\u5b58\u5728\u6570\u5c0f\u65f6\u6ede\u540e\u3002 \u4e8c\u3001\u6784\u5efa\u5185\u6838\u6f0f\u6d1e\u68c0\u6d4b\u7684\u4e09\u5c42eBPF\u6a21\u578b 1. \u7cfb\u7edf\u8c03\u7528\u76d1\u63a7\u5c42 \u901a\u8fc7\u6302\u94a9sys_enter\/sys_exit\u7b49\u8ddf\u8e2a\u70b9\uff0ceBPF\u7a0b\u5e8f\u80fd\u6355\u83b7\u6240\u6709\u7528\u6237\u6001\u4e0e\u5185\u6838\u6001\u7684\u4ea4\u4e92\u884c\u4e3a\u3002\u4f8b\u5982\uff1a \u68c0\u6d4b\u7f13\u51b2\u533a\u6ea2\u51fa\uff1a\u76d1\u63a7copy_from_user\u51fd\u6570\u7684size\u53c2\u6570\u662f\u5426\u8d85\u8fc7\u76ee\u6807\u7f13\u51b2\u533a\u957f\u5ea6\u3002 \u8bc6\u522b\u5f02\u5e38\u6743\u9650\u64cd\u4f5c\uff1a\u8bb0\u5f55\u975e\u7279\u6743\u8fdb\u7a0b\u8c03\u7528capset\u6216ioctl\u7684\u654f\u611f\u6307\u4ee4\u3002 \/\/ \u793a\u4f8b\uff1a\u68c0\u6d4bexecve\u8c03\u7528\u7684\u975e\u6cd5\u53c2\u6570 SEC(&quot;tracepoint\/syscalls\/sys_enter_execve&quot;) int handle_execve(struct trace_event_raw_sys_enter *ctx) { char filename[256]; bpf_probe_read_user_str(filename, sizeof(filename), (void *)ctx-&gt;args[0]); if (str_contains(filename, &quot;..\/&quot;)) { \/\/ \u68c0\u6d4b\u8def\u5f84\u7a7f\u8d8a\u7279\u5f81 bpf_printk(&quot;Suspicious execve: %s&quot;, filename); block_process(); } return 0; } 2. \u5185\u6838\u51fd\u6570\u5ba1\u8ba1\u5c42 \u501f\u52a9kprobe\/uprobe\uff0ceBPF\u80fd\u591f\u6df1\u5165\u5185\u6838\u51fd\u6570\u5185\u90e8\uff0c\u5ba1\u8ba1\u5185\u5b58\u5206\u914d\u3001\u9501\u72b6\u6001\u7b49\u5173\u952e\u64cd\u4f5c\uff1a \u5185\u5b58\u5b89\u5168\u68c0\u6d4b\uff1a\u8ffd\u8e2akmalloc\/kfree\u8c03\u7528\u5e8f\u5217\uff0c\u8bc6\u522b\u91cd\u590d\u91ca\u653e\uff08Double Free\uff09\u6216\u91ca\u653e\u540e\u4f7f\u7528\uff08UAF\uff09\u6f0f\u6d1e\u3002 \u6570\u636e\u7ade\u4e89\u5206\u6790\uff1a\u76d1\u63a7\u81ea\u65cb\u9501\uff08spinlock\uff09\u7684\u6301\u6709\u65f6\u95f4\uff0c\u53d1\u73b0\u672a\u6b63\u786e\u91ca\u653e\u9501\u7684\u4ee3\u7801\u8def\u5f84\u3002 3. \u884c\u4e3a\u6a21\u5f0f\u5173\u8054\u5c42 \u5c06eBPF\u4e8b\u4ef6\u4e0e\u7528\u6237\u6001\u65e5\u5fd7\u7ed3\u5408\uff0c\u5229\u7528\u673a\u5668\u5b66\u4e60\u6a21\u578b\u8bc6\u522b\u653b\u51fb\u94fe\u3002\u4f8b\u5982\uff0c\u7ed3\u5408Falco\u7b49\u5de5\u5177\uff0c\u53ef\u6784\u5efa\u89c4\u5219\uff1a [&hellip;]<\/p>\n","protected":false},"author":4,"featured_media":35459,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[14],"tags":[],"class_list":["post-35458","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-product-news"],"_links":{"self":[{"href":"https:\/\/www.yunshan.net\/blog\/wp-json\/wp\/v2\/posts\/35458","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.yunshan.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.yunshan.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.yunshan.net\/blog\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.yunshan.net\/blog\/wp-json\/wp\/v2\/comments?post=35458"}],"version-history":[{"count":1,"href":"https:\/\/www.yunshan.net\/blog\/wp-json\/wp\/v2\/posts\/35458\/revisions"}],"predecessor-version":[{"id":35460,"href":"https:\/\/www.yunshan.net\/blog\/wp-json\/wp\/v2\/posts\/35458\/revisions\/35460"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.yunshan.net\/blog\/wp-json\/wp\/v2\/media\/35459"}],"wp:attachment":[{"href":"https:\/\/www.yunshan.net\/blog\/wp-json\/wp\/v2\/media?parent=35458"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.yunshan.net\/blog\/wp-json\/wp\/v2\/categories?post=35458"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.yunshan.net\/blog\/wp-json\/wp\/v2\/tags?post=35458"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}