From 5dab2faddc8eaa1fb1abdbe2f502001fc13a1b21 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Wed, 26 Mar 2014 13:05:43 +0100 Subject: qcow2: Check refcount table size (CVE-2014-0144) Limit the in-memory reference count table size to 8 MB, it's enough in practice. This fixes an unbounded allocation as well as a buffer overflow in qcow2_refcount_init(). Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Signed-off-by: Stefan Hajnoczi --- tests/qemu-iotests/080 | 10 ++++++++++ tests/qemu-iotests/080.out | 7 +++++++ 2 files changed, 17 insertions(+) (limited to 'tests') diff --git a/tests/qemu-iotests/080 b/tests/qemu-iotests/080 index 6d588dd..6179e05 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 48c40aa..6fef6d9 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 -- cgit v1.1