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 <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Alberto Garcia 2018-03-06 18:14:07 +02:00 committed by Kevin Wolf
parent 0cf0e5980b
commit 314e8d3928
3 changed files with 21 additions and 5 deletions

View File

@ -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,

View File

@ -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

View File

@ -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)