1 files changed, 14 insertions, 24 deletions

diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
index 0b229ebd57..ff53df4451 100644
--- a/tools/virtiofsd/passthrough_ll.c
+++ b/tools/virtiofsd/passthrough_ll.c
@@ -620,7 +620,7 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr,
     struct lo_inode *inode;
     int ifd;
     int res;
-    int fd;
+    int fd = -1;
 
     inode = lo_inode(req, ino);
     if (!inode) {
@@ -2393,8 +2393,6 @@ static void setup_wait_parent_capabilities(void)
 static void setup_namespaces(struct lo_data *lo, struct fuse_session *se)
 {
     pid_t child;
-    char template[] = "virtiofsd-XXXXXX";
-    char *tmpdir;
 
     /*
      * Create a new pid namespace for *child* processes.  We'll have to
@@ -2458,33 +2456,23 @@ static void setup_namespaces(struct lo_data *lo, struct fuse_session *se)
         exit(1);
     }
 
-    tmpdir = mkdtemp(template);
-    if (!tmpdir) {
-        fuse_log(FUSE_LOG_ERR, "tmpdir(%s): %m\n", template);
-        exit(1);
-    }
-
-    if (mount("/proc/self/fd", tmpdir, NULL, MS_BIND, NULL) < 0) {
-        fuse_log(FUSE_LOG_ERR, "mount(/proc/self/fd, %s, MS_BIND): %m\n",
-                 tmpdir);
+    /*
+     * We only need /proc/self/fd. Prevent ".." from accessing parent
+     * directories of /proc/self/fd by bind-mounting it over /proc. Since / was
+     * previously remounted with MS_REC | MS_SLAVE this mount change only
+     * affects our process.
+     */
+    if (mount("/proc/self/fd", "/proc", NULL, MS_BIND, NULL) < 0) {
+        fuse_log(FUSE_LOG_ERR, "mount(/proc/self/fd, MS_BIND): %m\n");
         exit(1);
     }
 
-    /* Now we can get our /proc/self/fd directory file descriptor */
-    lo->proc_self_fd = open(tmpdir, O_PATH);
+    /* Get the /proc (actually /proc/self/fd, see above) file descriptor */
+    lo->proc_self_fd = open("/proc", O_PATH);
     if (lo->proc_self_fd == -1) {
-        fuse_log(FUSE_LOG_ERR, "open(%s, O_PATH): %m\n", tmpdir);
+        fuse_log(FUSE_LOG_ERR, "open(/proc, O_PATH): %m\n");
         exit(1);
     }
-
-    if (umount2(tmpdir, MNT_DETACH) < 0) {
-        fuse_log(FUSE_LOG_ERR, "umount2(%s, MNT_DETACH): %m\n", tmpdir);
-        exit(1);
-    }
-
-    if (rmdir(tmpdir) < 0) {
-        fuse_log(FUSE_LOG_ERR, "rmdir(%s): %m\n", tmpdir);
-    }
 }
 
 /*
@@ -2839,6 +2827,8 @@ int main(int argc, char *argv[])
     /* Don't mask creation mode, kernel already did that */
     umask(0);
 
+    qemu_init_exec_dir(argv[0]);
+
     pthread_mutex_init(&lo.mutex, NULL);
     lo.inodes = g_hash_table_new(lo_key_hash, lo_key_equal);
     lo.root.fd = -1;