From: Rafał Miłecki <zajec5@gmail.com>
Date: Wed, 22 Apr 2015 19:07:19 +0000 (+0000)
Subject: nvram: refuse to open NVRAM for writing if it's too big to be handled
X-Git-Tag: reboot~3177
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=3931288caa4da33d45571d9101010e95d8739738;p=oweals%2Fopenwrt.git

nvram: refuse to open NVRAM for writing if it's too big to be handled

Otherwise writing anything will result in loosing data.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>

SVN-Revision: 45565
---

diff --git a/package/utils/nvram/src/nvram.c b/package/utils/nvram/src/nvram.c
index f2c79ff7ba..0e1c726837 100644
--- a/package/utils/nvram/src/nvram.c
+++ b/package/utils/nvram/src/nvram.c
@@ -389,8 +389,8 @@ nvram_handle_t * nvram_open(const char *file, int rdonly)
 
 				header = nvram_header(h);
 
-				if( header->magic == NVRAM_MAGIC )
-				{
+				if (header->magic == NVRAM_MAGIC &&
+				    (rdonly || header->len < NVRAM_SPACE)) {
 					_nvram_rehash(h);
 					free(mtd);
 					return h;