critical_partition_protect: Use absolute path

Signed-off-by: sekaiacg <[email protected]>
AndroidPatch · May 3, 2024 · 40957d6 · 40957d6
1 parent 240069f
commit 40957d6
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Showing 2 changed files with 66 additions and 16 deletions.
diff --git a/src/critical_partition_protect/critical_partition_protect.c b/src/critical_partition_protect/critical_partition_protect.c
@@ -15,39 +15,45 @@
 
 #include <kpm_utils.h>
 #include <kpm_hook_utils.h>
+#include "file.h"
 
 KPM_NAME("Anti Format Critical Partition");
 KPM_VERSION(ANTI_FORMAT_VERSION);
 KPM_LICENSE("GPL v2");
 KPM_AUTHOR("1f2003d5");
 KPM_DESCRIPTION("通过拦截内核调用对关键分区进行保护，防止被恶意格机");
 
-struct open_flags {
-	int open_flag;
-	umode_t mode;
-	int acc_mode;
-	int intent;
-	int lookup_flags;
-};
+char *skfunc_def(d_path)(const struct path *path, char *buf, int buflen) = NULL;
+void skfunc_def(fput)(struct file *file) = NULL;
 
 hook_func_def(do_filp_open, struct file *, int dfd, struct filename *pathname, const struct open_flags *o);
 hook_func_no_info(do_filp_open);
 static struct file *hook_replace(do_filp_open)(int dfd, struct filename *pathname, const struct open_flags *o)
 {
-    const char *currFN = pathname->name;
-    if (unlikely(strstr(currFN, "/dev") != NULL) && unlikely(strstr(currFN, "/block") != NULL)) {
-        // Check write mode
-        if ((o->open_flag & (O_WRONLY | O_RDWR | O_CREAT | O_TRUNC)) != 0) {
-            if (unlikely(strstr(currFN, "/sd") != NULL) || unlikely(strstr(currFN, "/loop") != NULL) || unlikely(strstr(currFN, "/mapper") != NULL) || unlikely(strstr(currFN, "/dm-") != NULL) || unlikely(strstr(currFN, "/by-name") != NULL) || unlikely(strstr(currFN, "/bootdevice") != NULL)) {
+    struct file *filp = hook_call_backup(do_filp_open, dfd, pathname, o);
+    if (!IS_ERR(filp)) {
+        char tmp[100] = { 0 };
+        char *currFN = skfunc(d_path)(&filp->f_path, tmp, 100);
 #ifdef DEBUG
-                pr_info("[AntiFormatDevice] %s, open_flag: %d, mode: %d", currFN, o->open_flag, o->mode);
+        pr_info("[AntiFormatDevice] %s", currFN);
 #endif
-                pr_err("[AntiFormatDevice] Evil operation, disallowed!");
-                return ERR_PTR(-EACCES);
+        if (currFN) {
+            if (unlikely(strstr(currFN, "/dev") != NULL) && unlikely(strstr(currFN, "/block") != NULL)) {
+                // Check write mode
+                if ((o->open_flag & (O_WRONLY | O_RDWR | O_CREAT | O_TRUNC)) != 0) {
+                    if (unlikely(strstr(currFN, "/sd") != NULL) || unlikely(strstr(currFN, "/loop") != NULL) || unlikely(strstr(currFN, "/mapper") != NULL) || unlikely(strstr(currFN, "/dm-") != NULL) || unlikely(strstr(currFN, "/by-name") != NULL) || unlikely(strstr(currFN, "/bootdevice") != NULL)) {
+#ifdef DEBUG
+                        pr_info("[AntiFormatDevice] %s, open_flag: %d, mode: %d", currFN, o->open_flag, o->mode);
+#endif
+                        pr_err("[AntiFormatDevice] Evil operation, disallowed!");
+                        skfunc(fput)(filp);
+                        return ERR_PTR(-EACCES);
+                    }
+                }
             }
         }
     }
-    return hook_call_backup(do_filp_open, dfd, pathname, o);
+    return filp;
 }
 
 static inline bool installHook() {
@@ -91,6 +97,18 @@ static long anti_format_device_init(const char *args, const char *event, void *_
     pr_info("[AntiFormatDevice] Kernel Patch Version: %x\n", kpver);
     pr_info("[AntiFormatDevice] Initializing...\n");
 
+    skfunc_match(d_path, NULL, NULL);
+    if (!skfunc(d_path)) {
+    	pr_info("[AntiFormatDevice] kernel func: 'd_path' does not exist!\n");
+    	goto exit;
+    }
+
+    skfunc_match(fput, NULL, NULL);
+    if (!skfunc(fput)) {
+    	pr_info("[AntiFormatDevice] kernel func: 'fput' does not exist!\n");
+    	goto exit;
+    }
+
     if (anti_format_device_control_internal(true)) {
         pr_info("[AntiFormatDevice] Module initializing completed.\n");
         goto exit;

diff --git a/src/critical_partition_protect/file.h b/src/critical_partition_protect/file.h
@@ -0,0 +1,32 @@
+#ifndef _KPM_FILE_H
+#define _KPM_FILE_H
+
+#include <linux/llist.h>
+#include <ktypes.h>
+
+struct vfsmount;
+struct dentry;
+
+struct path {
+    struct vfsmount *mnt;
+    struct dentry *dentry;
+};
+
+struct file {
+    union {
+        struct llist_node    fu_llist;
+        struct rcu_head      fu_rcuhead;
+    } f_u;
+    struct path     f_path;
+    struct inode    *f_inode;
+};
+
+struct open_flags {
+    int open_flag;
+    umode_t mode;
+    int acc_mode;
+    int intent;
+    int lookup_flags;
+};
+
+#endif //_KPM_FILE_H