From patchwork Fri Aug 19 02:03:48 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 12948237 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 BB75CC28B2B for ; Fri, 19 Aug 2022 02:03:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240319AbiHSCDn (ORCPT ); Thu, 18 Aug 2022 22:03:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52680 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241413AbiHSCDk (ORCPT ); Thu, 18 Aug 2022 22:03:40 -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 A37E75723B for ; Thu, 18 Aug 2022 19:03:39 -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 3EF8D6143D for ; Fri, 19 Aug 2022 02:03:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A9211C433D7; Fri, 19 Aug 2022 02:03:38 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.96) (envelope-from ) id 1oOrMU-0038Rr-08; Thu, 18 Aug 2022 22:03:50 -0400 From: Steven Rostedt To: linux-trace-devel@vger.kernel.org Cc: "Steven Rostedt (Google)" Subject: [PATCH 2/3] libtracefs: Remove double free attempt of new_event in tracefs_synth_echo_cmd() Date: Thu, 18 Aug 2022 22:03:48 -0400 Message-Id: <20220819020349.747429-3-rostedt@goodmis.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220819020349.747429-1-rostedt@goodmis.org> References: <20220819020349.747429-1-rostedt@goodmis.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org From: "Steven Rostedt (Google)" The "out_free" path frees the synth->dyn_event if new_event is set, but it is also freed in the success path (that falls through into the out_free path). The only reason this did not crash is because both cases set the "synth->dyn_event" to NULL, where the second attempt to free it does nothing. But this is still a bug. Fixes: d7c5dbb7a231e ("libtracefs: Use the internal dynamic events API when creating synthetic events") Signed-off-by: Steven Rostedt (Google) --- src/tracefs-hist.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/src/tracefs-hist.c b/src/tracefs-hist.c index 6f7d657bd404..302b9a75e6ee 100644 --- a/src/tracefs-hist.c +++ b/src/tracefs-hist.c @@ -2311,11 +2311,6 @@ int tracefs_synth_echo_cmd(struct trace_seq *seq, hist, path, synth->end_event->system, synth->end_event->name); - if (new_event) { - tracefs_dynevent_free(synth->dyn_event); - synth->dyn_event = NULL; - } - ret = 0; out_free: free(hist);