From e9f562a8b76be91513cd253d6633772e3e5dd1c3 Mon Sep 17 00:00:00 2001
From: LoveSy <shana@zju.edu.cn>
Date: Wed, 2 Feb 2022 18:39:13 +0800
Subject: [PATCH] Fix abuse of `fdopendir`
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

After `fdopendir`, the fd is no longer usable. Should dup and
make use of RAII

Co-authored-by: 残页 <31466456+canyie@users.noreply.github.com>
---
 native/jni/core/restorecon.cpp | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/native/jni/core/restorecon.cpp b/native/jni/core/restorecon.cpp
index b97de1d0d..307866648 100644
--- a/native/jni/core/restorecon.cpp
+++ b/native/jni/core/restorecon.cpp
@@ -15,7 +15,6 @@ using namespace std;
 
 static void restore_syscon(int dirfd) {
     struct dirent *entry;
-    DIR *dir;
     char *con;
 
     if (fgetfilecon(dirfd, &con) >= 0) {
@@ -24,11 +23,12 @@ static void restore_syscon(int dirfd) {
         freecon(con);
     }
 
-    dir = xfdopendir(dirfd);
-    while ((entry = xreaddir(dir))) {
+    auto dir = xopen_dir(dirfd);
+    while ((entry = xreaddir(dir.get()))) {
         int fd = openat(dirfd, entry->d_name, O_RDONLY | O_CLOEXEC);
         if (entry->d_type == DT_DIR) {
             restore_syscon(fd);
+            continue;
         } else if (entry->d_type == DT_REG) {
             if (fgetfilecon(fd, &con) >= 0) {
                 if (con[0] == '\0' || strcmp(con, UNLABEL_CON) == 0 || strcmp(con, ADB_CON) == 0)
@@ -47,16 +47,16 @@ static void restore_syscon(int dirfd) {
 
 static void restore_magiskcon(int dirfd) {
     struct dirent *entry;
-    DIR *dir;
 
     fsetfilecon(dirfd, MAGISK_CON);
     fchown(dirfd, 0, 0);
 
-    dir = xfdopendir(dirfd);
-    while ((entry = xreaddir(dir))) {
+    auto dir = xopen_dir(dirfd);
+    while ((entry = xreaddir(dir.get()))) {
         int fd = xopenat(dirfd, entry->d_name, O_RDONLY | O_CLOEXEC);
         if (entry->d_type == DT_DIR) {
             restore_magiskcon(fd);
+            continue;
         } else if (entry->d_type) {
             fsetfilecon(fd, MAGISK_CON);
             fchown(fd, 0, 0);
@@ -71,12 +71,8 @@ void restorecon() {
         lsetfilecon(SECURE_DIR, ADB_CON);
     close(fd);
     lsetfilecon(MODULEROOT, SYSTEM_CON);
-    fd = xopen(MODULEROOT, O_RDONLY | O_CLOEXEC);
-    restore_syscon(fd);
-    close(fd);
-    fd = xopen(DATABIN, O_RDONLY | O_CLOEXEC);
-    restore_magiskcon(fd);
-    close(fd);
+    restore_syscon(xopen(MODULEROOT, O_RDONLY | O_CLOEXEC));
+    restore_magiskcon(xopen(DATABIN, O_RDONLY | O_CLOEXEC));
 }
 
 void restore_tmpcon() {