openwrt/target/linux/brcm47xx/patches-3.18/031-04-MIPS-BCM47XX-Use-strnchr-to-avoid-reading-out-of-the.patch

From 80aaaa8b93d860f828e2cf883f307894640765f0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <zajec5@gmail.com>
Date: Wed, 10 Dec 2014 11:49:54 +0100
Subject: [PATCH] MIPS: BCM47XX: Use strnchr to avoid reading out of the buffer
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Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8662/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 arch/mips/bcm47xx/nvram.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/arch/mips/bcm47xx/nvram.c
+++ b/arch/mips/bcm47xx/nvram.c
@@ -175,7 +175,7 @@ static int nvram_init(void)
 int bcm47xx_nvram_getenv(const char *name, char *val, size_t val_len)
 {
 	char *var, *value, *end, *eq;
-	int err;
+	int data_left, err;
 
 	if (!name)
 		return -EINVAL;
@@ -191,7 +191,9 @@ int bcm47xx_nvram_getenv(const char *nam
 	end = nvram_buf + sizeof(nvram_buf) - 2;
 	end[0] = end[1] = '\0';
 	for (; *var; var = value + strlen(value) + 1) {
-		eq = strchr(var, '=');
+		data_left = end - var;
+
+		eq = strnchr(var, data_left, '=');
 		if (!eq)
 			break;
 		value = eq + 1;