From 3a9af0bd34410a255d27024ea1bc28dc4e3a0044 Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook@chromium.org>
Date: Tue, 17 Feb 2015 13:47:58 -0800
Subject: samples/seccomp: improve label helper

Fixes a potential corruption with uninitialized stack memory in the
seccomp BPF sample program.

[akpm@linux-foundation.org: coding-style fixlet]
Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Robert Swiecki <swiecki@google.com>
Tested-by: Robert Swiecki <swiecki@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 samples/seccomp/bpf-helper.c | 6 ++++++
 1 file changed, 6 insertions(+)

(limited to 'samples/seccomp/bpf-helper.c')

diff --git a/samples/seccomp/bpf-helper.c b/samples/seccomp/bpf-helper.c
index 579cfe331886..05cb4d5ff9f5 100644
--- a/samples/seccomp/bpf-helper.c
+++ b/samples/seccomp/bpf-helper.c
@@ -10,6 +10,7 @@
  */
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 
 #include "bpf-helper.h"
@@ -63,6 +64,11 @@ __u32 seccomp_bpf_label(struct bpf_labels *labels, const char *label)
 {
 	struct __bpf_label *begin = labels->labels, *end;
 	int id;
+
+	if (labels->count == BPF_LABELS_MAX) {
+		fprintf(stderr, "Too many labels\n");
+		exit(1);
+	}
 	if (labels->count == 0) {
 		begin->label = label;
 		begin->location = 0xffffffff;
-- 
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