diff options
| -rw-r--r-- | block/qcow2-refcount.c | 4 | ||||
| -rw-r--r-- | block/qcow2.c | 9 | ||||
| -rwxr-xr-x | tests/qemu-iotests/080 | 10 | ||||
| -rw-r--r-- | tests/qemu-iotests/080.out | 7 |
4 files changed, 29 insertions, 1 deletions
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index 4a2df5fb99..e3c7ecdcc9 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -40,8 +40,10 @@ static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs, int qcow2_refcount_init(BlockDriverState *bs) { BDRVQcowState *s = bs->opaque; - int ret, refcount_table_size2, i; + unsigned int refcount_table_size2, i; + int ret; + assert(s->refcount_table_size <= INT_MAX / sizeof(uint64_t)); refcount_table_size2 = s->refcount_table_size * sizeof(uint64_t); s->refcount_table = g_malloc(refcount_table_size2); if (s->refcount_table_size > 0) { diff --git a/block/qcow2.c b/block/qcow2.c index f0411a9217..b9b6e70264 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -577,10 +577,19 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, s->csize_shift = (62 - (s->cluster_bits - 8)); s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; s->cluster_offset_mask = (1LL << s->csize_shift) - 1; + s->refcount_table_offset = header.refcount_table_offset; 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) */ + error_setg(errp, "Reference count table too large"); + ret = -EINVAL; + goto fail; + } + s->snapshots_offset = header.snapshots_offset; s->nb_snapshots = header.nb_snapshots; diff --git a/tests/qemu-iotests/080 b/tests/qemu-iotests/080 index 6d588ddd12..6179e0519f 100755 --- a/tests/qemu-iotests/080 +++ b/tests/qemu-iotests/080 @@ -45,6 +45,7 @@ _supported_os Linux header_size=104 offset_backing_file_offset=8 +offset_refcount_table_clusters=56 offset_header_size=100 offset_ext_magic=$header_size offset_ext_size=$((header_size + 4)) @@ -67,6 +68,15 @@ poke_file "$TEST_IMG" "$offset_ext_size" "\x7f\xff\xff\xff" poke_file "$TEST_IMG" "$offset_backing_file_offset" "\x00\x00\x00\x00\x00\x00\x00\x00" { $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir +echo +echo "== Huge refcount table size ==" +_make_test_img 64M +poke_file "$TEST_IMG" "$offset_refcount_table_clusters" "\xff\xff\xff\xff" +{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir +poke_file "$TEST_IMG" "$offset_refcount_table_clusters" "\x00\x02\x00\x01" +{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir + + # success, all done echo "*** done" rm -f $seq.full diff --git a/tests/qemu-iotests/080.out b/tests/qemu-iotests/080.out index 48c40aa3e2..6fef6d9892 100644 --- a/tests/qemu-iotests/080.out +++ b/tests/qemu-iotests/080.out @@ -13,4 +13,11 @@ qemu-io: can't open device TEST_DIR/t.qcow2: Invalid backing file offset no file open, try 'help open' qemu-io: can't open device TEST_DIR/t.qcow2: Header extension too large no file open, try 'help open' + +== Huge refcount table size == +Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 +qemu-io: can't open device TEST_DIR/t.qcow2: Reference count table too large +no file open, try 'help open' +qemu-io: can't open device TEST_DIR/t.qcow2: Reference count table too large +no file open, try 'help open' *** done |