From 49abfcafed0da643a61cb964e9f36831f4187d11 Mon Sep 17 00:00:00 2001
From: LoveSy <shana@zju.edu.cn>
Date: Tue, 26 Oct 2021 01:50:29 +0800
Subject: [PATCH] Fix nullptr dereference when env abnormal

---
 native/jni/core/module.cpp | 51 +++++++++++++++++++-------------------
 1 file changed, 26 insertions(+), 25 deletions(-)

diff --git a/native/jni/core/module.cpp b/native/jni/core/module.cpp
index 102a6caff..7af22ee1b 100644
--- a/native/jni/core/module.cpp
+++ b/native/jni/core/module.cpp
@@ -574,34 +574,35 @@ void magic_mount() {
 
     char buf[4096];
     LOGI("* Loading modules\n");
-    for (const auto &m : *modules) {
-        const char *module = m.name.data();
-        char *b = buf + sprintf(buf, "%s/" MODULEMNT "/%s/", MAGISKTMP.data(), module);
+    if (modules) {
+        for (const auto &m : *modules) {
+            const char *module = m.name.data();
+            char *b = buf + sprintf(buf, "%s/" MODULEMNT "/%s/", MAGISKTMP.data(), module);
 
-        // Read props
-        strcpy(b, "system.prop");
-        if (access(buf, F_OK) == 0) {
-            LOGI("%s: loading [system.prop]\n", module);
-            load_prop_file(buf, false);
+            // Read props
+            strcpy(b, "system.prop");
+            if (access(buf, F_OK) == 0) {
+                LOGI("%s: loading [system.prop]\n", module);
+                load_prop_file(buf, false);
+            }
+
+            // Check whether skip mounting
+            strcpy(b, "skip_mount");
+            if (access(buf, F_OK) == 0)
+                continue;
+
+            // Double check whether the system folder exists
+            strcpy(b, "system");
+            if (access(buf, F_OK) != 0)
+                continue;
+
+            LOGI("%s: loading mount files\n", module);
+            b[-1] = '\0';
+            int fd = xopen(buf, O_RDONLY | O_CLOEXEC);
+            system->collect_files(module, fd);
+            close(fd);
         }
-
-        // Check whether skip mounting
-        strcpy(b, "skip_mount");
-        if (access(buf, F_OK) == 0)
-            continue;
-
-        // Double check whether the system folder exists
-        strcpy(b, "system");
-        if (access(buf, F_OK) != 0)
-            continue;
-
-        LOGI("%s: loading mount files\n", module);
-        b[-1] = '\0';
-        int fd = xopen(buf, O_RDONLY | O_CLOEXEC);
-        system->collect_files(module, fd);
-        close(fd);
     }
-
     if (MAGISKTMP != "/sbin") {
         // Need to inject our binaries into /system/bin
         inject_magisk_bins(system);