From: DJ Delorie <dj@redhat.com>
To: libc-stable@sourceware.org
Subject: [COMMITTED 2.34] nss: handle stat failure in check_reload_and_get (BZ #28752)
Date: Mon, 13 Jun 2022 22:59:45 -0400 [thread overview]
Message-ID: <xn7d5kne5a.fsf@greed.delorie.com> (raw)
Skip the chroot test if the database isn't loaded
correctly (because the chroot test uses some
existing DB state).
The __stat64_time64 -> fstatat call can fail if
running under an (aggressive) seccomp filter,
like Firefox seems to use.
This manifested in a crash when using glib built
with FAM support with such a Firefox build.
Suggested-by: DJ Delorie <dj@redhat.com>
Signed-off-by: Sam James <sam@gentoo.org>
Reviewed-by: DJ Delorie <dj@redhat.com>
(cherry picked from commit ace9e3edbca62d978b1e8f392d8a5d78500272d9)
diff --git a/nss/nss_database.c b/nss/nss_database.c
index 54561f0328..e807e9d84c 100644
--- a/nss/nss_database.c
+++ b/nss/nss_database.c
@@ -420,23 +420,32 @@ nss_database_check_reload_and_get (struct nss_database_state *local,
return true;
}
- /* Before we reload, verify that "/" hasn't changed. We assume that
- errors here are very unlikely, but the chance that we're entering
- a container is also very unlikely, so we err on the side of both
- very unlikely things not happening at the same time. */
- if (__stat64_time64 ("/", &str) != 0
- || (local->root_ino != 0
- && (str.st_ino != local->root_ino
- || str.st_dev != local->root_dev)))
+ int stat_rv = __stat64_time64 ("/", &str);
+
+ if (local->data.services[database_index] != NULL)
{
- /* 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);
- return true;
+ /* Before we reload, verify that "/" hasn't changed. We assume that
+ errors here are very unlikely, but the chance that we're entering
+ a container is also very unlikely, so we err on the side of both
+ very unlikely things not happening at the same time. */
+ if (stat_rv != 0
+ || (local->root_ino != 0
+ && (str.st_ino != local->root_ino
+ || str.st_dev != local->root_dev)))
+ {
+ /* 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);
+ return true;
+ }
+ }
+ if (stat_rv == 0)
+ {
+ local->root_ino = str.st_ino;
+ local->root_dev = str.st_dev;
}
- local->root_ino = str.st_ino;
- local->root_dev = str.st_dev;
+
__libc_lock_unlock (local->lock);
/* Avoid overwriting the global configuration until we have loaded
reply other threads:[~2022-06-14 2:59 UTC|newest]
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