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authorMax Reitz <mreitz@redhat.com>2014-03-07 23:10:12 +0100
committerStefan Hajnoczi <stefanha@redhat.com>2014-03-13 14:23:27 +0100
commit26d49c46750aff62c8c6e7a8b14c79d4114a8e53 (patch)
tree4216a8ea7edb623480dfcc839598b683c969810a
parent750036a848ea913ba6343718ffa70da98f7eef6b (diff)
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qcow2-refcount: Sanitize refcount table entry
When reading the refcount table entry in get_refcount(), only bits which are actually significant for the refcount block offset should be taken into account. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
-rw-r--r--block/qcow2-refcount.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 8712d8bd54..6151148507 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -96,7 +96,8 @@ static int get_refcount(BlockDriverState *bs, int64_t cluster_index)
refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT);
if (refcount_table_index >= s->refcount_table_size)
return 0;
- refcount_block_offset = s->refcount_table[refcount_table_index];
+ refcount_block_offset =
+ s->refcount_table[refcount_table_index] & REFT_OFFSET_MASK;
if (!refcount_block_offset)
return 0;