Commit 54c42368 authored by Anthony Liguori's avatar Anthony Liguori
Browse files

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: default avatarKevin Wolf <kwolf@redhat.com>
Signed-off-by: default avatarAnthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@7217 c046a42c-6fe2-441c-8c8c-71466251a162
parent ae2f14af

block-qcow2.c

+14 −0
Original line number Diff line number Diff line
@@ -2666,6 +2666,13 @@ static int check_refcounts_l2(BlockDriverState *bs, 
                errors += inc_refcounts(bs, refcount_table,

                              refcount_table_size,

                              offset, s->cluster_size);



                /* Correct offsets are cluster aligned */

                if (offset & (s->cluster_size - 1)) {

                    fprintf(stderr, "ERROR offset=%" PRIx64 ": Cluster is not "

                        "properly aligned; L2 entry corrupted.\n", offset);

                    errors++;

                }

            }

        }

    }
@@ -2734,6 +2741,13 @@ static int check_refcounts_l1(BlockDriverState *bs, 
                          l2_offset,

                          s->cluster_size);



            /* L2 tables are cluster aligned */

            if (l2_offset & (s->cluster_size - 1)) {

                fprintf(stderr, "ERROR l2_offset=%" PRIx64 ": Table is not "

                    "cluster aligned; L1 entry corrupted\n", l2_offset);

                errors++;

            }



            /* Process and check L2 entries */

            ret = check_refcounts_l2(bs, refcount_table, refcount_table_size,

                l2_offset, check_copied);