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From:   Andreas Schwab <schwab@suse.de>
To:     Steven Rostedt <rostedt@goodmis.org>
Cc:     Daniel Bristot de Oliveira <bristot@kernel.org>,
        linux-trace-devel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2] rtla: Fix double free
References: <mvmzggxl4n1.fsf@suse.de>
        <fd0888a4-099c-95fe-7e20-82be1489061f@kernel.org>
        <mvmv8rll2yn.fsf@suse.de> <20220725105639.295a7d7d@gandalf.local.home>
Date:   Mon, 25 Jul 2022 17:12:18 +0200
In-Reply-To: <20220725105639.295a7d7d@gandalf.local.home> (Steven Rostedt's
        message of "Mon, 25 Jul 2022 10:56:39 -0400")
Message-ID: <mvmilnlkyzx.fsf_-_@suse.de>
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.1.90 (gnu/linux)
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Avoid double free by making trace_instance_destroy indempotent.  When
trace_instance_init fails, it calls trace_instance_destroy, but its only
caller osnoise_destroy_tool calls it again.

Fixes: 0605bf009f18 ("rtla: Add osnoise tool")
Signed-off-by: Andreas Schwab <schwab@suse.de>
---
 tools/tracing/rtla/src/trace.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/tools/tracing/rtla/src/trace.c b/tools/tracing/rtla/src/trace.c
index 5784c9f9e570..e1ba6d9f4265 100644
--- a/tools/tracing/rtla/src/trace.c
+++ b/tools/tracing/rtla/src/trace.c
@@ -134,13 +134,18 @@ void trace_instance_destroy(struct trace_instance *trace)
 	if (trace->inst) {
 		disable_tracer(trace->inst);
 		destroy_instance(trace->inst);
+		trace->inst = NULL;
 	}
 
-	if (trace->seq)
+	if (trace->seq) {
 		free(trace->seq);
+		trace->seq = NULL;
+	}
 
-	if (trace->tep)
+	if (trace->tep) {
 		tep_free(trace->tep);
+		trace->tep = NULL;
+	}
 }
 
 /*
-- 
2.37.1


-- 
Andreas Schwab, SUSE Labs, schwab@suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE  1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."