From: Sam James <sam@gentoo.org>
To: libc-alpha@sourceware.org
Subject: [PATCH v4 2/2] nss: handle stat failure in check_reload_and_get (BZ #28752)
Date: Sun, 5 Jun 2022 04:57:10 +0100 [thread overview]
Message-ID: <20220605035710.832386-2-sam@gentoo.org> (raw)
In-Reply-To: <20220605035710.832386-1-sam@gentoo.org>
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>
---
nss/nss_database.c | 39 ++++++++++++++++++++++++---------------
1 file changed, 24 insertions(+), 15 deletions(-)
diff --git a/nss/nss_database.c b/nss/nss_database.c
index d56c5b798d..f2ed2f2c25 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
--
2.35.1
next prev parent reply other threads:[~2022-06-05 3:57 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-05 3:57 [PATCH v4 1/2] nss: add assert to DB_LOOKUP_FCT " Sam James
2022-06-05 3:57 ` Sam James [this message]
2022-06-09 1:29 ` [PATCH v4 2/2] nss: handle stat failure in check_reload_and_get " DJ Delorie
2022-06-09 1:29 ` [PATCH v4 1/2] nss: add assert to DB_LOOKUP_FCT " DJ Delorie
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