[Qemu-devel] [PATCH] vmdk: fix endianness bugs

[Alexander Graf]

The vmdk code is sloppy when handling the header descriptor during
creation of an image. Fix all header accesses in the create path to
either store native endianness or convert it when appropriate.

Reported-by: Yury Tsarev <address@hidden>
Signed-off-by: Alexander Graf <address@hidden>
---
 block/vmdk.c |   22 ++++++++++++++--------
 1 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/block/vmdk.c b/block/vmdk.c
index 8fc9d67..922b23d 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -716,11 +716,11 @@ static int vmdk_create(const char *filename, 
QEMUOptionParameter *options)
         return -errno;
     magic = cpu_to_be32(VMDK4_MAGIC);
     memset(&header, 0, sizeof(header));
-    header.version = cpu_to_le32(1);
-    header.flags = cpu_to_le32(3); /* ?? */
-    header.capacity = cpu_to_le64(total_size);
-    header.granularity = cpu_to_le64(128);
-    header.num_gtes_per_gte = cpu_to_le32(512);
+    header.version = 1;
+    header.flags = 3; /* ?? */
+    header.capacity = total_size;
+    header.granularity = 128;
+    header.num_gtes_per_gte = 512;
 
     grains = (total_size + header.granularity - 1) / header.granularity;
     gt_size = ((header.num_gtes_per_gte * sizeof(uint32_t)) + 511) >> 9;
@@ -736,6 +736,12 @@ static int vmdk_create(const char *filename, 
QEMUOptionParameter *options)
          header.granularity - 1) / header.granularity) *
         header.granularity;
 
+    /* swap endianness for all header fields */
+    header.version = cpu_to_le32(header.version);
+    header.flags = cpu_to_le32(header.flags);
+    header.capacity = cpu_to_le64(header.capacity);
+    header.granularity = cpu_to_le64(header.granularity);
+    header.num_gtes_per_gte = cpu_to_le32(header.num_gtes_per_gte);
     header.desc_offset = cpu_to_le64(header.desc_offset);
     header.desc_size = cpu_to_le64(header.desc_size);
     header.rgd_offset = cpu_to_le64(header.rgd_offset);
@@ -759,7 +765,7 @@ static int vmdk_create(const char *filename, 
QEMUOptionParameter *options)
         goto exit;
     }
 
-    ret = ftruncate(fd, header.grain_offset << 9);
+    ret = ftruncate(fd, le64_to_cpu(header.grain_offset) << 9);
     if (ret < 0) {
         ret = -errno;
         goto exit;
@@ -767,7 +773,7 @@ static int vmdk_create(const char *filename, 
QEMUOptionParameter *options)
 
     /* write grain directory */
     lseek(fd, le64_to_cpu(header.rgd_offset) << 9, SEEK_SET);
-    for (i = 0, tmp = header.rgd_offset + gd_size;
+    for (i = 0, tmp = le64_to_cpu(header.rgd_offset) + gd_size;
          i < gt_count; i++, tmp += gt_size) {
         ret = qemu_write_full(fd, &tmp, sizeof(tmp));
         if (ret != sizeof(tmp)) {
@@ -778,7 +784,7 @@ static int vmdk_create(const char *filename, 
QEMUOptionParameter *options)
 
     /* write backup grain directory */
     lseek(fd, le64_to_cpu(header.gd_offset) << 9, SEEK_SET);
-    for (i = 0, tmp = header.gd_offset + gd_size;
+    for (i = 0, tmp = le64_to_cpu(header.gd_offset) + gd_size;
          i < gt_count; i++, tmp += gt_size) {
         ret = qemu_write_full(fd, &tmp, sizeof(tmp));
         if (ret != sizeof(tmp)) {
-- 
1.6.0.2