commit 17f0ff097887008b2d3dca270c8ffbb4b43a8749
Author: Sergei Trofimovich <slyfox@gentoo.org>
Date:   Fri Feb 5 07:32:18 2021 +0000

    nsswitch: return result when nss database is locked [BZ #27343]
    
    Before the change nss_database_check_reload_and_get() did not populate
    the '*result' value when it returned success in a case of chroot
    detection. This caused initgroups() to use garage pointer in the
    following test (extracted from unbound):
    
    ```
    
    int main() {
        // load some NSS modules
        struct passwd * pw = getpwnam("root");
    
        chdir("/tmp");
        chroot("/tmp");
        chdir("/");
        // access nsswitch.conf in a chroot
        initgroups("root", 0);
    }
    ```
    
    Reviewed-by: DJ Delorie <dj@redhat.com>

diff --git a/nss/nss_database.c b/nss/nss_database.c
index cf0306adc47f12d9..e1bef6bd75ce0160 100644
--- a/nss/nss_database.c
+++ b/nss/nss_database.c
@@ -398,8 +398,9 @@ nss_database_check_reload_and_get (struct nss_database_state *local,
 	  && (str.st_ino != local->root_ino
 	      ||  str.st_dev != local->root_dev)))
     {
-      /* Change detected; disable reloading.  */
+      /* Change detected; disable reloading and return current state.  */
       atomic_store_release (&local->data.reload_disabled, 1);
+      *result = local->data.services[database_index];
       __libc_lock_unlock (local->lock);
       __nss_module_disable_loading ();
       return true;