nss: handle stat failure in check_reload_and_get (BZ #28752)

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>
This commit is contained in:
Sam James 2022-06-05 04:57:10 +01:00 committed by DJ Delorie
parent 3fdf0a205b
commit ace9e3edbc

View File

@ -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;
}
}
local->root_ino = str.st_ino;
local->root_dev = str.st_dev;
if (stat_rv == 0)
{
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