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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Xiaoke Wang <xkernel.wang@foxmail.com>,
        "Steven Rostedt (Google)" <rostedt@goodmis.org>
Subject: [PATCH 5.15 021/171] tracing/histogram: Fix a potential memory leak for kstrdup()
Date:   Mon, 31 Jan 2022 11:54:46 +0100
Message-Id: <20220131105230.739166002@linuxfoundation.org>
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From: Xiaoke Wang <xkernel.wang@foxmail.com>

commit e629e7b525a179e29d53463d992bdee759c950fb upstream.

kfree() is missing on an error path to free the memory allocated by
kstrdup():

  p = param = kstrdup(data->params[i], GFP_KERNEL);

So it is better to free it via kfree(p).

Link: https://lkml.kernel.org/r/tencent_C52895FD37802832A3E5B272D05008866F0A@qq.com

Cc: stable@vger.kernel.org
Fixes: d380dcde9a07c ("tracing: Fix now invalid var_ref_vals assumption in trace action")
Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 kernel/trace/trace_events_hist.c |    1 +
 1 file changed, 1 insertion(+)

--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -3581,6 +3581,7 @@ static int trace_action_create(struct hi
 
 			var_ref_idx = find_var_ref_idx(hist_data, var_ref);
 			if (WARN_ON(var_ref_idx < 0)) {
+				kfree(p);
 				ret = var_ref_idx;
 				goto err;
 			}