diff options
| author | Kevin Wolf <kwolf@redhat.com> | 2014-03-26 13:05:50 +0100 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2014-04-01 15:22:34 +0200 |
| commit | 2b5d5953eec0cc541857c3df812bdf8421596ab2 (patch) | |
| tree | 46005cfd30454c30b3e4853a8146e1ac260bee3c | |
| parent | db8a31d11d6a60f48d6817530640d75aa72a9a2f (diff) | |
qcow2: Check new refcount table size on growth
If the size becomes larger than what qcow2_open() would accept, fail the
growing operation.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
| -rw-r--r-- | block/qcow2-refcount.c | 4 | ||||
| -rw-r--r-- | block/qcow2.c | 4 | ||||
| -rw-r--r-- | block/qcow2.h | 9 |
3 files changed, 14 insertions, 3 deletions
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index 561d65925c..1c78ff8c97 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 d4d991cbb3..b64564d171 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 b153505f5b..4015373bb0 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) { |