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authorKevin Wolf <kwolf@redhat.com>2014-03-26 13:06:06 +0100
committerStefan Hajnoczi <stefanha@redhat.com>2014-04-01 15:22:35 +0200
commit6a83f8b5bec6f59e56cc49bd49e4c3f8f805d56f (patch)
tree4063692109e5f06ece922daad860641ec0fe8421 /block
parentc05e4667be91b46ab42b5a11babf8e84d476cc6b (diff)
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qcow2: Check maximum L1 size in qcow2_snapshot_load_tmp() (CVE-2014-0143)
This avoids an unbounded allocation. 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 'block')
-rw-r--r--block/qcow2-snapshot.c4
-rw-r--r--block/qcow2.c4
-rw-r--r--block/qcow2.h4
3 files changed, 9 insertions, 3 deletions
diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
index 715168e..5db4f30 100644
--- a/block/qcow2-snapshot.c
+++ b/block/qcow2-snapshot.c
@@ -680,6 +680,10 @@ int qcow2_snapshot_load_tmp(BlockDriverState *bs,
sn = &s->snapshots[snapshot_index];
/* Allocate and read in the snapshot's L1 table */
+ if (sn->l1_size > QCOW_MAX_L1_SIZE) {
+ error_setg(errp, "Snapshot L1 table too large");
+ return -EFBIG;
+ }
new_l1_bytes = sn->l1_size * sizeof(uint64_t);
new_l1_table = g_malloc0(align_offset(new_l1_bytes, 512));
diff --git a/block/qcow2.c b/block/qcow2.c
index be48a27..bb6000f 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -638,9 +638,7 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,
}
/* 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) */
+ if (header.l1_size > QCOW_MAX_L1_SIZE) {
error_setg(errp, "Active L1 table too large");
ret = -EFBIG;
goto fail;
diff --git a/block/qcow2.h b/block/qcow2.h
index 3649465..f28e7d9 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -44,6 +44,10 @@
* (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
#define QCOW_MAX_REFTABLE_SIZE 0x800000
+/* 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) */
+#define QCOW_MAX_L1_SIZE 0x2000000
+
/* 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) */