From nobody Thu Jan 8 10:53:43 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4E3DEE748E6 for ; Sat, 30 Sep 2023 20:37:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232955AbjI3Uhb (ORCPT ); Sat, 30 Sep 2023 16:37:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53156 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231779AbjI3UhZ (ORCPT ); Sat, 30 Sep 2023 16:37:25 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0DFB8EB for ; Sat, 30 Sep 2023 13:37:23 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AC8DAC43391; Sat, 30 Sep 2023 20:37:22 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.96) (envelope-from ) id 1qmgjG-004N19-0l; Sat, 30 Sep 2023 16:38:22 -0400 Message-ID: <20230930203822.053304721@goodmis.org> User-Agent: quilt/0.66 Date: Sat, 30 Sep 2023 16:32:17 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Andrew Morton Subject: [for-linus][PATCH 4/4] eventfs: Test for dentries array allocated in eventfs_release() References: <20230930203213.826737400@goodmis.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: "Steven Rostedt (Google)" The dcache_dir_open_wrapper() could be called when a dynamic event is being deleted leaving a dentry with no children. In this case the dlist->dentries array will never be allocated. This needs to be checked for in eventfs_release(), otherwise it will trigger a NULL pointer dereference. Link: https://lore.kernel.org/linux-trace-kernel/20230930090106.1c3164e9@ro= rschach.local.home Cc: Mark Rutland Acked-by: Masami Hiramatsu (Google) Fixes: ef36b4f92868 ("eventfs: Remember what dentries were created on dir o= pen") Signed-off-by: Steven Rostedt (Google) --- fs/tracefs/event_inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 5f1714089884..8c8d64e76103 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -421,7 +421,7 @@ static int eventfs_release(struct inode *inode, struct = file *file) if (WARN_ON_ONCE(!dlist)) return -EINVAL; =20 - for (i =3D 0; dlist->dentries[i]; i++) { + for (i =3D 0; dlist->dentries && dlist->dentries[i]; i++) { dput(dlist->dentries[i]); } =20 --=20 2.40.1