diff options
| author | Kevin Wolf <kwolf@redhat.com> | 2014-03-28 18:06:31 +0100 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2014-04-01 15:21:03 +0200 |
| commit | b106ad9185f35fc4ad669555ad0e79e276083bd7 (patch) | |
| tree | 180dbb92f35c3299780f066ec023266ab90bc508 /tests/qemu-iotests/026.out | |
| parent | 6d33e8e7dc9d40ea105feed4b39caa3e641569e8 (diff) | |
qcow2: Don't rely on free_cluster_index in alloc_refcount_block() (CVE-2014-0147)
free_cluster_index is only correct if update_refcount() was called from
an allocation function, and even there it's brittle because it's used to
protect unfinished allocations which still have a refcount of 0 - if it
moves in the wrong place, the unfinished allocation can be corrupted.
So not using it any more seems to be a good idea. Instead, use the
first requested cluster to do the calculations. Return -EAGAIN if
unfinished allocations could become invalid and let the caller restart
its search for some free clusters.
The context of creating a snapsnot is one situation where
update_refcount() is called outside of a cluster allocation. For this
case, the change fixes a buffer overflow if a cluster is referenced in
an L2 table that cannot be represented by an existing refcount block.
(new_table[refcount_table_index] was out of bounds)
[Bump the qemu-iotests 026 refblock_alloc.write leak count from 10 to
11.
--Stefan]
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'tests/qemu-iotests/026.out')
| -rw-r--r-- | tests/qemu-iotests/026.out | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/tests/qemu-iotests/026.out b/tests/qemu-iotests/026.out index 15045799a2..f7c78e712a 100644 --- a/tests/qemu-iotests/026.out +++ b/tests/qemu-iotests/026.out @@ -475,7 +475,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: refblock_alloc.write_blocks; errno: 28; imm: off; once: off; write write failed: No space left on device -10 leaked clusters were found on the image. +11 leaked clusters were found on the image. This means waste of disk space, but no harm to data. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 @@ -499,7 +499,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: refblock_alloc.write_table; errno: 28; imm: off; once: off; write write failed: No space left on device -10 leaked clusters were found on the image. +11 leaked clusters were found on the image. This means waste of disk space, but no harm to data. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 @@ -523,7 +523,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: refblock_alloc.switch_table; errno: 28; imm: off; once: off; write write failed: No space left on device -10 leaked clusters were found on the image. +11 leaked clusters were found on the image. This means waste of disk space, but no harm to data. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 |