From nobody Wed Feb 11 14:20:46 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 961B3C6FD1F for ; Tue, 14 Mar 2023 19:04:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230523AbjCNTEN (ORCPT ); Tue, 14 Mar 2023 15:04:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56246 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230203AbjCNTEJ (ORCPT ); Tue, 14 Mar 2023 15:04:09 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AF7DFF77A; Tue, 14 Mar 2023 12:03:27 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9334D61965; Tue, 14 Mar 2023 19:03:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0EAA7C433A0; Tue, 14 Mar 2023 19:03:11 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.96) (envelope-from ) id 1pc9vS-009ty7-0A; Tue, 14 Mar 2023 15:03:10 -0400 Message-ID: <20230314190309.859934963@goodmis.org> User-Agent: quilt/0.66 Date: Tue, 14 Mar 2023 15:02:38 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Andrew Morton , stable@vger.kernel.org, Mark Rutland Subject: [for-linus][PATCH 2/5] tracing: Check field value in hist_field_name() References: <20230314190236.203370742@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 function hist_field_name() cannot handle being passed a NULL field parameter. It should never be NULL, but due to a previous bug, NULL was passed to the function and the kernel crashed due to a NULL dereference. Mark Rutland reported this to me on IRC. The bug was fixed, but to prevent future bugs from crashing the kernel, check the field and add a WARN_ON() if it is NULL. Link: https://lkml.kernel.org/r/20230302020810.762384440@goodmis.org Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Andrew Morton Reported-by: Mark Rutland Fixes: c6afad49d127f ("tracing: Add hist trigger 'sym' and 'sym-offset' mod= ifiers") Tested-by: Mark Rutland Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_events_hist.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_h= ist.c index 6e8ab726a7b5..486cca3c2b75 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -1331,6 +1331,9 @@ static const char *hist_field_name(struct hist_field = *field, { const char *field_name =3D ""; =20 + if (WARN_ON_ONCE(!field)) + return field_name; + if (level > 1) return field_name; =20 --=20 2.39.1