gwj / at91sam9263 · Commits

Commit 54c42368f57c02b0970bb32b4542f99b913908ba

Authored by aliguori
1 parent ae2f14af

qcow2: Add plausibility check for L1/L2 entries (Kevin Wolf) 

From: Kevin Wolf <kwolf@redhat.com>

All L1 and L2 entries must point at the start of a cluster. If there is some
offset into the cluster, the entry is corrupted.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@7217 c046a42c-6fe2-441c-8c8c-71466251a162
Inline Side-by-side
Showing 1 changed file with 14 additions and 0 deletions
block-qcow2.c
  View file @54c4236
... ... @@ -2666,6 +2666,13 @@ static int check_refcounts_l2(BlockDriverState *bs,
2666 2666 errors += inc_refcounts(bs, refcount_table,
2667 2667 refcount_table_size,
2668 2668 offset, s->cluster_size);
  2669 +
  2670 + /* Correct offsets are cluster aligned */
  2671 + if (offset & (s->cluster_size - 1)) {
  2672 + fprintf(stderr, "ERROR offset=%" PRIx64 ": Cluster is not "
  2673 + "properly aligned; L2 entry corrupted.\n", offset);
  2674 + errors++;
  2675 + }
2669 2676 }
2670 2677 }
2671 2678 }
... ... @@ -2734,6 +2741,13 @@ static int check_refcounts_l1(BlockDriverState *bs,
2734 2741 l2_offset,
2735 2742 s->cluster_size);
2736 2743  
  2744 + /* L2 tables are cluster aligned */
  2745 + if (l2_offset & (s->cluster_size - 1)) {
  2746 + fprintf(stderr, "ERROR l2_offset=%" PRIx64 ": Table is not "
  2747 + "cluster aligned; L1 entry corrupted\n", l2_offset);
  2748 + errors++;
  2749 + }
  2750 +
2737 2751 /* Process and check L2 entries */
2738 2752 ret = check_refcounts_l2(bs, refcount_table, refcount_table_size,
2739 2753 l2_offset, check_copied);
... ...