From 6ce116dda5d5a7708d660e32713ff40fc3f749ef Mon Sep 17 00:00:00 2001
From: Jeff Cody <jcody@redhat.com>
Date: Tue, 25 Mar 2014 14:23:24 +0100
Subject: [PATCH 17/49] vdi: add bounds checks for blocks_in_image and disk_size header fields (CVE-2014-0144)

RH-Author: Kevin Wolf <kwolf@redhat.com>
Message-id: <1395753835-7591-18-git-send-email-kwolf@redhat.com>
Patchwork-id: n/a
O-Subject: [virt-devel] [EMBARGOED RHEL-7.0 qemu-kvm PATCH 17/48] vdi: add bounds checks for blocks_in_image and disk_size header fields (CVE-2014-0144)
Bugzilla: 1079455
RH-Acked-by: Jeff Cody <jcody@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>

From: Jeff Cody <jcody@redhat.com>

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1079455
Upstream status: Embargoed

The maximum blocks_in_image is 0xffffffff / 4, which also limits the
maximum disk_size for a VDI image.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Conflicts:
block/vdi.c

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/vdi.c |   26 ++++++++++++++++++++++++--
 1 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/block/vdi.c b/block/vdi.c
index f973883..0457298 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -120,6 +120,12 @@ typedef unsigned char uuid_t[16];
 
 #define VDI_IS_ALLOCATED(X) ((X) < VDI_DISCARDED)
 
+#define VDI_BLOCK_SIZE           (1 * MiB)
+/* max blocks in image is (0xffffffff / 4) */
+#define VDI_BLOCKS_IN_IMAGE_MAX  0x3fffffff
+#define VDI_DISK_SIZE_MAX        ((uint64_t)VDI_BLOCKS_IN_IMAGE_MAX * \
+                                  (uint64_t)VDI_BLOCK_SIZE)
+
 #if !defined(CONFIG_UUID)
 static inline void uuid_generate(uuid_t out)
 {
@@ -385,6 +391,11 @@ static int vdi_open(BlockDriverState *bs, QDict *options, int flags,
     vdi_header_print(&header);
 #endif
 
+    if (header.disk_size > VDI_DISK_SIZE_MAX) {
+        ret = -EINVAL;
+        goto fail;
+    }
+
     if (header.disk_size % SECTOR_SIZE != 0) {
         /* 'VBoxManage convertfromraw' can create images with odd disk sizes.
            We accept them but round the disk size to the next multiple of
@@ -417,7 +428,7 @@ static int vdi_open(BlockDriverState *bs, QDict *options, int flags,
         logout("unsupported sector size %u B\n", header.sector_size);
         ret = -ENOTSUP;
         goto fail;
-    } else if (header.block_size != 1 * MiB) {
+    } else if (header.block_size != VDI_BLOCK_SIZE) {
         logout("unsupported block size %u B\n", header.block_size);
         ret = -ENOTSUP;
         goto fail;
@@ -434,6 +445,10 @@ static int vdi_open(BlockDriverState *bs, QDict *options, int flags,
         logout("parent uuid != 0, unsupported\n");
         ret = -ENOTSUP;
         goto fail;
+    } else if (header.blocks_in_image > VDI_BLOCKS_IN_IMAGE_MAX) {
+        logout("unsupported number of blocks in image\n");
+        ret = -ENOTSUP;
+        goto fail;
     }
 
     bs->total_sectors = header.disk_size / SECTOR_SIZE;
@@ -682,11 +697,17 @@ static int vdi_create(const char *filename, QEMUOptionParameter *options,
         options++;
     }
 
+    if (bytes > VDI_DISK_SIZE_MAX) {
+        result = -EINVAL;
+        goto exit;
+    }
+
     fd = qemu_open(filename,
                    O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE,
                    0644);
     if (fd < 0) {
-        return -errno;
+        result = -errno;
+        goto exit;
     }
 
     /* We need enough blocks to store the given disk size,
@@ -747,6 +768,7 @@ static int vdi_create(const char *filename, QEMUOptionParameter *options,
         result = -errno;
     }
 
+exit:
     return result;
 }
 
-- 
1.7.1