tracing-Plug-memory-leak-in-histogram_show.patch

From d28b33f44b57ec171be735fd12511e6059672376 Mon Sep 17 00:00:00 2001
From: Carsten Emde <C.Emde@osadl.org>
Date: Wed, 24 Feb 2010 07:49:32 +0100
Subject: [PATCH] tracing: Plug memory leak in histogram_show

commit d28b33f44b57ec171be735fd12511e6059672376 in tip.

Do not allocate memory for index pointer, if index out of range.

Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Carsten Emde <C.Emde@osadl.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/kernel/trace/latency_hist.c b/kernel/trace/latency_hist.c
index 8300929..9f20d61 100644
--- a/kernel/trace/latency_hist.c
+++ b/kernel/trace/latency_hist.c
@@ -218,13 +218,10 @@ void notrace latency_hist(int latency_type, int cpu, unsigned long latency,
 
 static void *l_start(struct seq_file *m, loff_t *pos)
 {
-	loff_t *index_ptr = kmalloc(sizeof(loff_t), GFP_KERNEL);
+	loff_t *index_ptr = NULL;
 	loff_t index = *pos;
 	struct hist_data *my_hist = m->private;
 
-	if (!index_ptr)
-		return NULL;
-
 	if (index == 0) {
 		char minstr[32], avgstr[32], maxstr[32];
 
@@ -263,10 +260,12 @@ static void *l_start(struct seq_file *m, loff_t *pos)
 			   MAX_ENTRY_NUM - my_hist->offset,
 			   "samples");
 	}
-	if (index >= MAX_ENTRY_NUM)
-		return NULL;
+	if (index < MAX_ENTRY_NUM) {
+		index_ptr = kmalloc(sizeof(loff_t), GFP_KERNEL);
+		if (index_ptr)
+			*index_ptr = index;
+	}
 
-	*index_ptr = index;
 	return index_ptr;
 }
 
-- 
1.7.1.1