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[Qemu-devel] [PULL for-2.0 31/51] qcow2: Check new refcount table size o
From: |
Stefan Hajnoczi |
Subject: |
[Qemu-devel] [PULL for-2.0 31/51] qcow2: Check new refcount table size on growth |
Date: |
Tue, 1 Apr 2014 19:19:09 +0200 |
From: Kevin Wolf <address@hidden>
If the size becomes larger than what qcow2_open() would accept, fail the
growing operation.
Signed-off-by: Kevin Wolf <address@hidden>
Reviewed-by: Max Reitz <address@hidden>
Signed-off-by: Stefan Hajnoczi <address@hidden>
---
block/qcow2-refcount.c | 4 ++++
block/qcow2.c | 4 +---
block/qcow2.h | 9 +++++++++
3 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 561d659..1c78ff8 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -311,6 +311,10 @@ static int alloc_refcount_block(BlockDriverState *bs,
uint64_t refcount_block_clusters = 1 << (s->cluster_bits - REFCOUNT_SHIFT);
uint64_t blocks_used = DIV_ROUND_UP(cluster_index,
refcount_block_clusters);
+ if (blocks_used > QCOW_MAX_REFTABLE_SIZE / sizeof(uint64_t)) {
+ return -EFBIG;
+ }
+
/* And now we need at least one block more for the new metadata */
uint64_t table_size = next_refcount_table_size(s, blocks_used + 1);
uint64_t last_table_size;
diff --git a/block/qcow2.c b/block/qcow2.c
index d4d991c..b64564d 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -609,9 +609,7 @@ static int qcow2_open(BlockDriverState *bs, QDict *options,
int flags,
s->refcount_table_size =
header.refcount_table_clusters << (s->cluster_bits - 3);
- if (header.refcount_table_clusters > (0x800000 >> s->cluster_bits)) {
- /* 8 MB refcount table is enough for 2 PB images at 64k cluster size
- * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
+ if (header.refcount_table_clusters > qcow2_max_refcount_clusters(s)) {
error_setg(errp, "Reference count table too large");
ret = -EINVAL;
goto fail;
diff --git a/block/qcow2.h b/block/qcow2.h
index b153505..4015373 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -40,6 +40,10 @@
#define QCOW_MAX_CRYPT_CLUSTERS 32
#define QCOW_MAX_SNAPSHOTS 65536
+/* 8 MB refcount table is enough for 2 PB images at 64k cluster size
+ * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
+#define QCOW_MAX_REFTABLE_SIZE 0x800000
+
/* indicate that the refcount of the referenced cluster is exactly one. */
#define QCOW_OFLAG_COPIED (1ULL << 63)
/* indicate that the cluster is compressed (they never have the copied flag) */
@@ -410,6 +414,11 @@ static inline int64_t qcow2_vm_state_offset(BDRVQcowState
*s)
return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
}
+static inline uint64_t qcow2_max_refcount_clusters(BDRVQcowState *s)
+{
+ return QCOW_MAX_REFTABLE_SIZE >> s->cluster_bits;
+}
+
static inline int qcow2_get_cluster_type(uint64_t l2_entry)
{
if (l2_entry & QCOW_OFLAG_COMPRESSED) {
--
1.9.0
- [Qemu-devel] [PULL for-2.0 20/51] vhdx: Bounds checking for block_size and logical_sector_size (CVE-2014-0148), (continued)
- [Qemu-devel] [PULL for-2.0 20/51] vhdx: Bounds checking for block_size and logical_sector_size (CVE-2014-0148), Stefan Hajnoczi, 2014/04/01
- [Qemu-devel] [PULL for-2.0 22/51] qcow2: Check header_length (CVE-2014-0144), Stefan Hajnoczi, 2014/04/01
- [Qemu-devel] [PULL for-2.0 23/51] qcow2: Check backing_file_offset (CVE-2014-0144), Stefan Hajnoczi, 2014/04/01
- [Qemu-devel] [PULL for-2.0 25/51] qcow2: Validate refcount table offset, Stefan Hajnoczi, 2014/04/01
- [Qemu-devel] [PULL for-2.0 24/51] qcow2: Check refcount table size (CVE-2014-0144), Stefan Hajnoczi, 2014/04/01
- [Qemu-devel] [PULL for-2.0 26/51] qcow2: Validate snapshot table offset/size (CVE-2014-0144), Stefan Hajnoczi, 2014/04/01
- [Qemu-devel] [PULL for-2.0 27/51] qcow2: Validate active L1 table offset and size (CVE-2014-0144), Stefan Hajnoczi, 2014/04/01
- [Qemu-devel] [PULL for-2.0 28/51] qcow2: Fix backing file name length check, Stefan Hajnoczi, 2014/04/01
- [Qemu-devel] [PULL for-2.0 29/51] qcow2: Don't rely on free_cluster_index in alloc_refcount_block() (CVE-2014-0147), Stefan Hajnoczi, 2014/04/01
- [Qemu-devel] [PULL for-2.0 30/51] qcow2: Avoid integer overflow in get_refcount (CVE-2014-0143), Stefan Hajnoczi, 2014/04/01
- [Qemu-devel] [PULL for-2.0 31/51] qcow2: Check new refcount table size on growth,
Stefan Hajnoczi <=
- [Qemu-devel] [PULL for-2.0 35/51] dmg: coding style and indentation cleanup, Stefan Hajnoczi, 2014/04/01
- [Qemu-devel] [PULL for-2.0 36/51] dmg: prevent out-of-bounds array access on terminator, Stefan Hajnoczi, 2014/04/01
- [Qemu-devel] [PULL for-2.0 34/51] qcow2: Fix new L1 table size check (CVE-2014-0143), Stefan Hajnoczi, 2014/04/01
- [Qemu-devel] [PULL for-2.0 32/51] qcow2: Fix types in qcow2_alloc_clusters and alloc_clusters_noref, Stefan Hajnoczi, 2014/04/01
- [Qemu-devel] [PULL for-2.0 33/51] qcow2: Protect against some integer overflows in bdrv_check, Stefan Hajnoczi, 2014/04/01
- [Qemu-devel] [PULL for-2.0 37/51] dmg: drop broken bdrv_pread() loop, Stefan Hajnoczi, 2014/04/01
- [Qemu-devel] [PULL for-2.0 38/51] dmg: use appropriate types when reading chunks, Stefan Hajnoczi, 2014/04/01
- [Qemu-devel] [PULL for-2.0 39/51] dmg: sanitize chunk length and sectorcount (CVE-2014-0145), Stefan Hajnoczi, 2014/04/01
- [Qemu-devel] [PULL for-2.0 41/51] dmg: prevent chunk buffer overflow (CVE-2014-0145), Stefan Hajnoczi, 2014/04/01
- [Qemu-devel] [PULL for-2.0 42/51] block: vdi bounds check qemu-io tests, Stefan Hajnoczi, 2014/04/01