diff options
| author | Max Reitz <mreitz@redhat.com> | 2014-09-05 16:07:18 +0200 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2014-09-22 11:39:28 +0100 |
| commit | a97c67ee6c1546b985c1048c7a1f9e4fc13d9ee1 (patch) | |
| tree | 521747581a617c39595dde3341f7a90cf0ac9751 /block/qcow2-refcount.c | |
| parent | adb435522b86b3fca2324cb8c94e17b55ae071f1 (diff) | |
qcow2: Check L1/L2/reftable entries for alignment
Offsets taken from the L1, L2 and refcount tables are generally assumed
to be correctly aligned. However, this cannot be guaranteed if the image
has been written to by something different than qemu, thus check all
offsets taken from these tables for correct cluster alignment.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1409926039-29044-5-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'block/qcow2-refcount.c')
| -rw-r--r-- | block/qcow2-refcount.c | 44 |
1 files changed, 42 insertions, 2 deletions
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index b9d421e153..2bcaaf9b98 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -108,6 +108,13 @@ static int get_refcount(BlockDriverState *bs, int64_t cluster_index) if (!refcount_block_offset) return 0; + if (offset_into_cluster(s, refcount_block_offset)) { + qcow2_signal_corruption(bs, true, -1, -1, "Refblock offset %#" PRIx64 + " unaligned (reftable index: %#" PRIx64 ")", + refcount_block_offset, refcount_table_index); + return -EIO; + } + ret = qcow2_cache_get(bs, s->refcount_block_cache, refcount_block_offset, (void**) &refcount_block); if (ret < 0) { @@ -181,6 +188,14 @@ static int alloc_refcount_block(BlockDriverState *bs, /* If it's already there, we're done */ if (refcount_block_offset) { + if (offset_into_cluster(s, refcount_block_offset)) { + qcow2_signal_corruption(bs, true, -1, -1, "Refblock offset %#" + PRIx64 " unaligned (reftable index: " + "%#x)", refcount_block_offset, + refcount_table_index); + return -EIO; + } + return load_refcount_block(bs, refcount_block_offset, (void**) refcount_block); } @@ -836,8 +851,14 @@ void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry, case QCOW2_CLUSTER_NORMAL: case QCOW2_CLUSTER_ZERO: if (l2_entry & L2E_OFFSET_MASK) { - qcow2_free_clusters(bs, l2_entry & L2E_OFFSET_MASK, - nb_clusters << s->cluster_bits, type); + if (offset_into_cluster(s, l2_entry & L2E_OFFSET_MASK)) { + qcow2_signal_corruption(bs, false, -1, -1, + "Cannot free unaligned cluster %#llx", + l2_entry & L2E_OFFSET_MASK); + } else { + qcow2_free_clusters(bs, l2_entry & L2E_OFFSET_MASK, + nb_clusters << s->cluster_bits, type); + } } break; case QCOW2_CLUSTER_UNALLOCATED: @@ -901,6 +922,14 @@ int qcow2_update_snapshot_refcount(BlockDriverState *bs, old_l2_offset = l2_offset; l2_offset &= L1E_OFFSET_MASK; + if (offset_into_cluster(s, l2_offset)) { + qcow2_signal_corruption(bs, true, -1, -1, "L2 table offset %#" + PRIx64 " unaligned (L1 index: %#x)", + l2_offset, i); + ret = -EIO; + goto fail; + } + ret = qcow2_cache_get(bs, s->l2_table_cache, l2_offset, (void**) &l2_table); if (ret < 0) { @@ -933,6 +962,17 @@ int qcow2_update_snapshot_refcount(BlockDriverState *bs, case QCOW2_CLUSTER_NORMAL: case QCOW2_CLUSTER_ZERO: + if (offset_into_cluster(s, offset & L2E_OFFSET_MASK)) { + qcow2_signal_corruption(bs, true, -1, -1, "Data " + "cluster offset %#llx " + "unaligned (L2 offset: %#" + PRIx64 ", L2 index: %#x)", + offset & L2E_OFFSET_MASK, + l2_offset, j); + ret = -EIO; + goto fail; + } + cluster_index = (offset & L2E_OFFSET_MASK) >> s->cluster_bits; if (!cluster_index) { /* unallocated */ |