tracing/histogram: Fix a potential memory leak for kstrdup()

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>

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 5e6a988..cd96106 100644 (file)
--- 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;
                        }