78 lines
2.9 KiB
Diff
78 lines
2.9 KiB
Diff
From: Kevin Wolf <kwolf@redhat.com>
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Date: Wed, 26 Mar 2014 13:05:50 +0100
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Subject: [PATCH] qcow2: Check new refcount table size on growth
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If the size becomes larger than what qcow2_open() would accept, fail the
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growing operation.
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Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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Reviewed-by: Max Reitz <mreitz@redhat.com>
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Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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(cherry picked from commit 2b5d5953eec0cc541857c3df812bdf8421596ab2)
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Conflicts:
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block/qcow2.c
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---
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block/qcow2-refcount.c | 4 ++++
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block/qcow2.c | 4 +---
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block/qcow2.h | 9 +++++++++
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3 files changed, 14 insertions(+), 3 deletions(-)
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diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
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index 3e473bd..3cdcfb6 100644
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--- a/block/qcow2-refcount.c
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+++ b/block/qcow2-refcount.c
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@@ -308,6 +308,10 @@ static int alloc_refcount_block(BlockDriverState *bs,
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uint64_t refcount_block_clusters = 1 << (s->cluster_bits - REFCOUNT_SHIFT);
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uint64_t blocks_used = DIV_ROUND_UP(cluster_index, refcount_block_clusters);
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+ if (blocks_used > QCOW_MAX_REFTABLE_SIZE / sizeof(uint64_t)) {
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+ return -EFBIG;
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+ }
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+
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/* And now we need at least one block more for the new metadata */
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uint64_t table_size = next_refcount_table_size(s, blocks_used + 1);
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uint64_t last_table_size;
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diff --git a/block/qcow2.c b/block/qcow2.c
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index 5d45036..af0a45c 100644
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--- a/block/qcow2.c
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+++ b/block/qcow2.c
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@@ -487,9 +487,7 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags)
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s->refcount_table_size =
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header.refcount_table_clusters << (s->cluster_bits - 3);
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- if (header.refcount_table_clusters > (0x800000 >> s->cluster_bits)) {
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- /* 8 MB refcount table is enough for 2 PB images at 64k cluster size
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- * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
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+ if (header.refcount_table_clusters > qcow2_max_refcount_clusters(s)) {
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fprintf(stderr, "Reference count table too large");
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ret = -EINVAL;
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goto fail;
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diff --git a/block/qcow2.h b/block/qcow2.h
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index 1e1294c..e802c55 100644
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--- a/block/qcow2.h
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+++ b/block/qcow2.h
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@@ -40,6 +40,10 @@
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#define QCOW_MAX_CRYPT_CLUSTERS 32
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#define QCOW_MAX_SNAPSHOTS 65536
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+/* 8 MB refcount table is enough for 2 PB images at 64k cluster size
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+ * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
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+#define QCOW_MAX_REFTABLE_SIZE 0x800000
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+
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/* indicate that the refcount of the referenced cluster is exactly one. */
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#define QCOW_OFLAG_COPIED (1LL << 63)
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/* indicate that the cluster is compressed (they never have the copied flag) */
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@@ -356,6 +360,11 @@ static inline int64_t qcow2_vm_state_offset(BDRVQcowState *s)
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return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
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}
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+static inline uint64_t qcow2_max_refcount_clusters(BDRVQcowState *s)
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+{
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+ return QCOW_MAX_REFTABLE_SIZE >> s->cluster_bits;
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+}
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+
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static inline int qcow2_get_cluster_type(uint64_t l2_entry)
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{
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if (l2_entry & QCOW_OFLAG_COMPRESSED) {
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