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authorPeter Lieven <pl@kamp.de>2019-09-10 17:26:22 +0200
committerKevin Wolf <kwolf@redhat.com>2019-10-14 17:12:48 +0200
commit6caaad46de02c02fb1eeaae64fcdc74f9e0a5eb0 (patch)
tree99d7f8c75d8a3ca43da59688a3a73731ea64961d /block/vhdx.c
parent22dbfdecc3c52228d3489da3fe81da92b21197bf (diff)
block/vhdx: add check for truncated image files
qemu is currently not able to detect truncated vhdx image files. Add a basic check if all allocated blocks are reachable at open and report all errors during bdrv_co_check. Signed-off-by: Peter Lieven <pl@kamp.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block/vhdx.c')
-rw-r--r--block/vhdx.c120
1 files changed, 103 insertions, 17 deletions
diff --git a/block/vhdx.c b/block/vhdx.c
index 6a09d0a55c..371f226286 100644
--- a/block/vhdx.c
+++ b/block/vhdx.c
@@ -24,6 +24,7 @@
#include "qemu/option.h"
#include "qemu/crc32c.h"
#include "qemu/bswap.h"
+#include "qemu/error-report.h"
#include "vhdx.h"
#include "migration/blocker.h"
#include "qemu/uuid.h"
@@ -235,6 +236,9 @@ static int vhdx_region_check(BDRVVHDXState *s, uint64_t start, uint64_t length)
end = start + length;
QLIST_FOREACH(r, &s->regions, entries) {
if (!((start >= r->end) || (end <= r->start))) {
+ error_report("VHDX region %" PRIu64 "-%" PRIu64 " overlaps with "
+ "region %" PRIu64 "-%." PRIu64, start, end, r->start,
+ r->end);
ret = -EINVAL;
goto exit;
}
@@ -877,6 +881,95 @@ static void vhdx_calc_bat_entries(BDRVVHDXState *s)
}
+static int vhdx_check_bat_entries(BlockDriverState *bs, int *errcnt)
+{
+ BDRVVHDXState *s = bs->opaque;
+ int64_t image_file_size = bdrv_getlength(bs->file->bs);
+ uint64_t payblocks = s->chunk_ratio;
+ uint64_t i;
+ int ret = 0;
+
+ if (image_file_size < 0) {
+ error_report("Could not determinate VHDX image file size.");
+ return image_file_size;
+ }
+
+ for (i = 0; i < s->bat_entries; i++) {
+ if ((s->bat[i] & VHDX_BAT_STATE_BIT_MASK) ==
+ PAYLOAD_BLOCK_FULLY_PRESENT) {
+ uint64_t offset = s->bat[i] & VHDX_BAT_FILE_OFF_MASK;
+ /*
+ * Allow that the last block exists only partially. The VHDX spec
+ * states that the image file can only grow in blocksize increments,
+ * but QEMU created images with partial last blocks in the past.
+ */
+ uint32_t block_length = MIN(s->block_size,
+ bs->total_sectors * BDRV_SECTOR_SIZE - i * s->block_size);
+ /*
+ * Check for BAT entry overflow.
+ */
+ if (offset > INT64_MAX - s->block_size) {
+ error_report("VHDX BAT entry %" PRIu64 " offset overflow.", i);
+ ret = -EINVAL;
+ if (!errcnt) {
+ break;
+ }
+ (*errcnt)++;
+ }
+ /*
+ * Check if fully allocated BAT entries do not reside after
+ * end of the image file.
+ */
+ if (offset >= image_file_size) {
+ error_report("VHDX BAT entry %" PRIu64 " start offset %" PRIu64
+ " points after end of file (%" PRIi64 "). Image"
+ " has probably been truncated.",
+ i, offset, image_file_size);
+ ret = -EINVAL;
+ if (!errcnt) {
+ break;
+ }
+ (*errcnt)++;
+ } else if (offset + block_length > image_file_size) {
+ error_report("VHDX BAT entry %" PRIu64 " end offset %" PRIu64
+ " points after end of file (%" PRIi64 "). Image"
+ " has probably been truncated.",
+ i, offset + block_length - 1, image_file_size);
+ ret = -EINVAL;
+ if (!errcnt) {
+ break;
+ }
+ (*errcnt)++;
+ }
+
+ /*
+ * verify populated BAT field file offsets against
+ * region table and log entries
+ */
+ if (payblocks--) {
+ /* payload bat entries */
+ int ret2;
+ ret2 = vhdx_region_check(s, offset, s->block_size);
+ if (ret2 < 0) {
+ ret = -EINVAL;
+ if (!errcnt) {
+ break;
+ }
+ (*errcnt)++;
+ }
+ } else {
+ payblocks = s->chunk_ratio;
+ /*
+ * Once differencing files are supported, verify sector bitmap
+ * blocks here
+ */
+ }
+ }
+ }
+
+ return ret;
+}
+
static void vhdx_close(BlockDriverState *bs)
{
BDRVVHDXState *s = bs->opaque;
@@ -981,25 +1074,15 @@ static int vhdx_open(BlockDriverState *bs, QDict *options, int flags,
goto fail;
}
- uint64_t payblocks = s->chunk_ratio;
- /* endian convert, and verify populated BAT field file offsets against
- * region table and log entries */
+ /* endian convert populated BAT field entires */
for (i = 0; i < s->bat_entries; i++) {
s->bat[i] = le64_to_cpu(s->bat[i]);
- if (payblocks--) {
- /* payload bat entries */
- if ((s->bat[i] & VHDX_BAT_STATE_BIT_MASK) ==
- PAYLOAD_BLOCK_FULLY_PRESENT) {
- ret = vhdx_region_check(s, s->bat[i] & VHDX_BAT_FILE_OFF_MASK,
- s->block_size);
- if (ret < 0) {
- goto fail;
- }
- }
- } else {
- payblocks = s->chunk_ratio;
- /* Once differencing files are supported, verify sector bitmap
- * blocks here */
+ }
+
+ if (!(flags & BDRV_O_CHECK)) {
+ ret = vhdx_check_bat_entries(bs, NULL);
+ if (ret < 0) {
+ goto fail;
}
}
@@ -2072,6 +2155,9 @@ static int coroutine_fn vhdx_co_check(BlockDriverState *bs,
if (s->log_replayed_on_open) {
result->corruptions_fixed++;
}
+
+ vhdx_check_bat_entries(bs, &result->corruptions);
+
return 0;
}