From 1dd3a44753f10970ded50950d28353c00bfcaf91 Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Mon, 14 Apr 2014 14:48:16 +0200
Subject: [PATCH] block: Limit size to INT_MAX in bdrv_check_byte_request()

Commit 8f4754ed intended to protect against integer overflow bugs in
block drivers by making sure that a single request that is passed to
drivers is no longer than INT_MAX bytes.

However, meanwhile there are some callers that don't use that code path
any more but call bdrv_check_byte_request() directy, so let's add a
check there as well.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
---
 block.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/block.c b/block.c
index 3b7951eb4f..5a0b421655 100644
--- a/block.c
+++ b/block.c
@@ -2581,6 +2581,10 @@ static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
 {
     int64_t len;
 
+    if (size > INT_MAX) {
+        return -EIO;
+    }
+
     if (!bdrv_is_inserted(bs))
         return -ENOMEDIUM;