diff options
| author | Alberto Garcia <berto@igalia.com> | 2017-11-03 16:18:52 +0200 |
|---|---|---|
| committer | Max Reitz <mreitz@redhat.com> | 2017-11-14 18:06:25 +0100 |
| commit | 8aa34834d566ba4e635d6029339a5f4f1ae1685e (patch) | |
| tree | 8708d307c07eb4f467d34f6bd0378234b6850792 /block/qcow2-refcount.c | |
| parent | 9883975050deffc147a3903d07ff995ecdc8a100 (diff) | |
qcow2: Prevent allocating compressed clusters at offset 0
If the refcount data is corrupted then we can end up trying to
allocate a new compressed cluster at offset 0 in the image, triggering
an assertion in qcow2_alloc_bytes() that would crash QEMU:
qcow2_alloc_bytes: Assertion `offset' failed.
This patch adds an explicit check for this scenario and a new test
case.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: fb53467cf48e95ff3330def1cf1003a5b862b7d9.1509718618.git.berto@igalia.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Diffstat (limited to 'block/qcow2-refcount.c')
| -rw-r--r-- | block/qcow2-refcount.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index 9059996c4b..60b8eef3e8 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -1082,6 +1082,13 @@ int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size) return new_cluster; } + if (new_cluster == 0) { + qcow2_signal_corruption(bs, true, -1, -1, "Preventing invalid " + "allocation of compressed cluster " + "at offset 0"); + return -EIO; + } + if (!offset || ROUND_UP(offset, s->cluster_size) != new_cluster) { offset = new_cluster; free_in_cluster = s->cluster_size; |