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>
s->nb_snapshots = header.nb_snapshots;
/* 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) */
+ error_setg(errp, "Active L1 table too large");
+ ret = -EFBIG;
+ goto fail;
+ }
s->l1_size = header.l1_size;
l1_vm_state_index = size_to_l1(s, header.size);
ret = -EINVAL;
goto fail;
}
+
+ ret = validate_table_offset(bs, header.l1_table_offset,
+ header.l1_size, sizeof(uint64_t));
+ if (ret < 0) {
+ error_setg(errp, "Invalid L1 table offset");
+ goto fail;
+ }
s->l1_table_offset = header.l1_table_offset;
+
+
if (s->l1_size > 0) {
s->l1_table = g_malloc0(
align_offset(s->l1_size * sizeof(uint64_t), 512));
header_size=104
offset_backing_file_offset=8
+offset_l1_size=36
+offset_l1_table_offset=40
offset_refcount_table_offset=48
offset_refcount_table_clusters=56
offset_nb_snapshots=60
{ $QEMU_IMG snapshot -c test $TEST_IMG; } 2>&1 | _filter_testdir
{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir
+echo
+echo "== Invalid L1 table =="
+_make_test_img 64M
+poke_file "$TEST_IMG" "$offset_l1_size" "\xff\xff\xff\xff"
+{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir
+poke_file "$TEST_IMG" "$offset_l1_size" "\x7f\xff\xff\xff"
+{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir
+
+poke_file "$TEST_IMG" "$offset_l1_table_offset" "\x7f\xff\xff\xff\xff\xff\x00\x00"
+poke_file "$TEST_IMG" "$offset_l1_size" "\x00\x00\xff\xff"
+{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir
+
+poke_file "$TEST_IMG" "$offset_l1_table_offset" "\x12\x34\x56\x78\x90\xab\xcd\xef"
+poke_file "$TEST_IMG" "$offset_l1_size" "\x00\x00\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
qemu-img: Could not create snapshot 'test': -27 (File too large)
read 512/512 bytes at offset 0
512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== Invalid L1 table ==
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+qemu-io: can't open device TEST_DIR/t.qcow2: Active L1 table too large
+no file open, try 'help open'
+qemu-io: can't open device TEST_DIR/t.qcow2: Active L1 table too large
+no file open, try 'help open'
+qemu-io: can't open device TEST_DIR/t.qcow2: Invalid L1 table offset
+no file open, try 'help open'
+qemu-io: can't open device TEST_DIR/t.qcow2: Invalid L1 table offset
+no file open, try 'help open'
*** done