From: Xiaoke Wang <xkernel.wang@foxmail.com>
Date: Tue, 25 Jan 2022 12:07:15 +0800
Subject: tracing/histogram: Fix a potential memory leak for kstrdup()
Git-commit: e629e7b525a179e29d53463d992bdee759c950fb
Patch-mainline: v5.17-rc2
References: git-fixes

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>
Acked-by: Miroslav Benes <mbenes@suse.cz>
---
 kernel/trace/trace_events_hist.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 5e6a988a8a51..cd9610688ddc 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -3935,6 +3935,7 @@ static int trace_action_create(struct hist_trigger_data *hist_data,
 
 			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;
 			}