From: Petr Štetiar <ynezz@true.cz>
Date: Tue, 10 Dec 2019 11:02:40 +0000 (+0100)
Subject: blobmsg: fix heap buffer overflow in blobmsg_parse
X-Git-Url: http://git.openwrt.org/?a=commitdiff_plain;h=f2b2ee441adb22bdcab7247589545eb27c941d78;p=project%2Flibubox.git

blobmsg: fix heap buffer overflow in blobmsg_parse

Fixes following error found by the fuzzer:

 ==29774==ERROR: AddressSanitizer: heap-buffer-overflow
 READ of size 1 at 0x6020004f1c56 thread T0
     #0 strcmp sanitizer_common_interceptors.inc:442:3
     #1 blobmsg_parse blobmsg.c:168:8

Signed-off-by: Petr Štetiar <ynezz@true.cz>
---

diff --git a/blobmsg.c b/blobmsg.c
index 1a8b783..71d4a36 100644
--- a/blobmsg.c
+++ b/blobmsg.c
@@ -53,6 +53,9 @@ bool blobmsg_check_attr(const struct blob_attr *attr, bool name)
 
 	id = blob_id(attr);
 	len = blobmsg_data_len(attr);
+	if (len > blob_raw_len(attr))
+		return false;
+
 	data = blobmsg_data(attr);
 
 	if (id > BLOBMSG_TYPE_LAST)