nsswitch: actually return the result when nss database is being locked
Commit Message
From: Sergei Trofimovich <slyfox@gentoo.org>
https://sourceware.org/bugzilla/show_bug.cgi?id=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);
}
```
---
nss/nss_database.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
Comments
slyich@gmail.com writes:
> - /* 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];
LGTM although I tweaked the patch subject for length. Committed.
Thanks!
Reviewed-by: DJ Delorie <dj@redhat.com>
@@ -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;