Received-SPF: pass (google.com: domain of linux-bluetooth-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Ildar Kamaletdinov <i.kamaletdinov@omp.ru>
To:     <linux-bluetooth@vger.kernel.org>
CC:     Ildar Kamaletdinov <i.kamaletdinov@omp.ru>
Subject: [PATCH BlueZ 4/7] tools: Prevent infinity loops in bluemoon.c
Date:   Fri, 1 Apr 2022 10:46:37 +0300
Message-ID: <20220401074640.3956695-5-i.kamaletdinov@omp.ru>
In-Reply-To: <20220401074640.3956695-1-i.kamaletdinov@omp.ru>
References: <20220401074640.3956695-1-i.kamaletdinov@omp.ru>
MIME-Version: 1.0
Content-Transfer-Encoding: 7BIT
Content-Type:   text/plain; charset=US-ASCII
Precedence: bulk

In case FW size is too big we can face with infinity while() loops.
According to C99 standart SIZE_MAX could be as small as 65535.

So to prevent overflow of 'firmware_offset' we must limit maximum FW
size that could be processed by bluemoon.

Found by Linux Verification Center (linuxtesting.org) with the SVACE
static analysis tool.
---
 tools/bluemoon.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/tools/bluemoon.c b/tools/bluemoon.c
index f50107a2a..729da36f6 100644
--- a/tools/bluemoon.c
+++ b/tools/bluemoon.c
@@ -492,6 +492,13 @@ static void request_firmware(const char *path)
 		return;
 	}
 
+	if (st.st_size > (SIZE_MAX - 4)) {
+		fprintf(stderr, "Firmware size is too big\n");
+		close(fd);
+		shutdown_device();
+		return;
+	}
+
 	firmware_data = malloc(st.st_size);
 	if (!firmware_data) {
 		fprintf(stderr, "Failed to allocate firmware buffer\n");
@@ -874,6 +881,12 @@ static void analyze_firmware(const char *path)
 		return;
 	}
 
+	if (st.st_size > (SIZE_MAX - 3)) {
+		fprintf(stderr, "Firmware size is too big\n");
+		close(fd);
+		return;
+	}
+
 	firmware_data = malloc(st.st_size);
 	if (!firmware_data) {
 		fprintf(stderr, "Failed to allocate firmware buffer\n");
-- 
2.34.0