From: Kevin Wolf Date: Wed, 26 Mar 2014 13:05:46 +0100 Subject: [PATCH] qcow2: Validate active L1 table offset and size (CVE-2014-0144) This avoids an unbounded allocation. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Signed-off-by: Stefan Hajnoczi (cherry picked from commit 2d51c32c4b511db8bb9e58208f1e2c25e4c06c85) Conflicts: tests/qemu-iotests/080 tests/qemu-iotests/080.out --- block/qcow2.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/block/qcow2.c b/block/qcow2.c index 43e2db1..8dd285b 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -520,6 +520,13 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags) s->nb_snapshots = header.nb_snapshots; /* read the level 1 table */ + if (header.l1_size > 0x2000000) { + /* 32 MB L1 table is enough for 2 PB images at 64k cluster size + * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */ + fprintf(stderr, "Active L1 table too large"); + ret = -EFBIG; + goto fail; + } s->l1_size = header.l1_size; l1_vm_state_index = size_to_l1(s, header.size); @@ -535,7 +542,16 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags) ret = -EINVAL; goto fail; } + + ret = validate_table_offset(bs, header.l1_table_offset, + header.l1_size, sizeof(uint64_t)); + if (ret < 0) { + fprintf(stderr, "Invalid L1 table offset"); + goto fail; + } s->l1_table_offset = header.l1_table_offset; + + if (s->l1_size > 0) { s->l1_table = g_malloc0( align_offset(s->l1_size * sizeof(uint64_t), 512));