From 314e8d3928aa82fa13673d47b5af7bdd9a6d82bf Mon Sep 17 00:00:00 2001 From: Alberto Garcia Date: Tue, 6 Mar 2018 18:14:07 +0200 Subject: [PATCH] qcow2: Check L1 table offset in qcow2_snapshot_load_tmp() This function checks that the size of a snapshot's L1 table is not too large, but it doesn't validate the offset. We now have a function to take care of this, so let's use it. Signed-off-by: Alberto Garcia Reviewed-by: Eric Blake Signed-off-by: Kevin Wolf --- block/qcow2-snapshot.c | 8 +++++--- tests/qemu-iotests/080 | 10 +++++++++- tests/qemu-iotests/080.out | 8 +++++++- 3 files changed, 21 insertions(+), 5 deletions(-) diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c index cee25f582b..bf94f4f434 100644 --- a/block/qcow2-snapshot.c +++ b/block/qcow2-snapshot.c @@ -704,9 +704,11 @@ 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 / sizeof(uint64_t)) { - error_setg(errp, "Snapshot L1 table too large"); - return -EFBIG; + ret = qcow2_validate_table(bs, sn->l1_table_offset, sn->l1_size, + sizeof(uint64_t), QCOW_MAX_L1_SIZE, + "Snapshot L1 table", errp); + if (ret < 0) { + return ret; } new_l1_bytes = sn->l1_size * sizeof(uint64_t); new_l1_table = qemu_try_blockalign(bs->file->bs, diff --git a/tests/qemu-iotests/080 b/tests/qemu-iotests/080 index 1c2bd85742..6a10e7defa 100755 --- a/tests/qemu-iotests/080 +++ b/tests/qemu-iotests/080 @@ -171,7 +171,15 @@ poke_file "$TEST_IMG" "$offset_l2_table_0" "\x80\x00\x00\xff\xff\xff\x00\x00" { $QEMU_IMG snapshot -c test $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir echo -echo "== Invalid snapshot L1 table ==" +echo "== Invalid snapshot L1 table offset ==" +_make_test_img 64M +{ $QEMU_IO -c "write 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir +{ $QEMU_IMG snapshot -c test $TEST_IMG; } 2>&1 | _filter_testdir +poke_file "$TEST_IMG" "$offset_snap1_l1_offset" "\x00\x00\x00\x00\x00\x40\x02\x00" +{ $QEMU_IMG convert -s test $TEST_IMG $TEST_IMG.snap; } 2>&1 | _filter_testdir + +echo +echo "== Invalid snapshot L1 table size ==" _make_test_img 64M { $QEMU_IO -c "write 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir { $QEMU_IMG snapshot -c test $TEST_IMG; } 2>&1 | _filter_testdir diff --git a/tests/qemu-iotests/080.out b/tests/qemu-iotests/080.out index 4c7790c9ee..f0d9038d55 100644 --- a/tests/qemu-iotests/080.out +++ b/tests/qemu-iotests/080.out @@ -59,7 +59,13 @@ wrote 512/512 bytes at offset 0 qemu-img: Could not create snapshot 'test': -27 (File too large) qemu-img: Could not create snapshot 'test': -11 (Resource temporarily unavailable) -== Invalid snapshot L1 table == +== Invalid snapshot L1 table offset == +Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 +wrote 512/512 bytes at offset 0 +512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) +qemu-img: Failed to load snapshot: Snapshot L1 table offset invalid + +== Invalid snapshot L1 table size == Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 wrote 512/512 bytes at offset 0 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)