| # 2009 June 3 |
| # |
| # The author disclaims copyright to this source code. In place of |
| # a legal notice, here is a blessing: |
| # |
| # May you do good and not evil. |
| # May you find forgiveness for yourself and forgive others. |
| # May you share freely, never taking more than you give. |
| # |
| #*********************************************************************** |
| # |
| # $Id: corruptD.test,v 1.2 2009/06/05 17:09:12 drh Exp $ |
| |
| set testdir [file dirname $argv0] |
| source $testdir/tester.tcl |
| |
| # Do not use a codec for tests in this file, as the database file is |
| # manipulated directly using tcl scripts (using the [hexio_write] command). |
| # |
| do_not_use_codec |
| |
| #-------------------------------------------------------------------------- |
| # OVERVIEW |
| # |
| # This test file attempts to verify that SQLite does not read past the |
| # end of any in-memory buffers as a result of corrupted database page |
| # images. Usually this happens because a field within a database page |
| # that contains an offset to some other structure within the same page |
| # is set to too large a value. A database page contains the following |
| # such fields: |
| # |
| # 1. The page header field that contains the offset to the first |
| # free block of space. |
| # |
| # 2. The first two bytes of all but the last free block on the free-block |
| # list (the offset to the next free block). |
| # |
| # 3. The page header field containing the number of cells on the page |
| # (implicitly defines the offset to the final element in the cell offset |
| # array, which could potentially be off the end of the page). |
| # |
| # 4. The page header field containing the offset to the start of the cell |
| # content area. |
| # |
| # 5. The contents of the cell offset array. |
| # |
| # 6. The first few bytes of each cell determine the size of the cell |
| # stored within the page, and hence the offset to the final byte of |
| # the cell. |
| # |
| # If any of the above fields are set to too large a value, then a buffer |
| # overread may occur. This test script creates and operates on various |
| # strategically corrupted database files to attempt to provoke such buffer |
| # overreads. |
| # |
| # Very often, a buffer overread passes unnoticed, particularly in workstation |
| # environments. For this reason, this test script should be run using valgrind |
| # (or similar) in order to verify that no overreads occur. |
| # |
| # TEST PLAN |
| # |
| # Test cases corruptD-1.* are white-box tests. They attempt to corrupt |
| # one of the above fields, then exercise each part of the code in btree.c |
| # that uses said field. |
| # |
| # Offset variables 1, 2, 3 and 4 are all checked to make sure they |
| # will not result in buffer overruns as part of page initialization in |
| # sqlite3BtreeInitPage(). Offsets 5 and 6 cannot be tested as part of |
| # page initialization, as trying to do so causes a performance hit. |
| # |
| |
| do_test corruptD-1.0 { |
| execsql { |
| PRAGMA auto_vacuum = 0; |
| PRAGMA page_size = 1024; |
| CREATE TABLE t1(a, b); |
| CREATE INDEX i1 ON t1(a, b); |
| } |
| for {set ii 1} {$ii < 50} {incr ii} { |
| execsql { INSERT INTO t1 VALUES($ii, $ii * $ii) } |
| } |
| execsql { |
| DELETE FROM t1 WHERE a = 10; |
| DELETE FROM t1 WHERE a = 20; |
| DELETE FROM t1 WHERE a = 30; |
| DELETE FROM t1 WHERE a = 40; |
| } |
| copy_file test.db test.bu |
| } {} |
| |
| proc incr_change_counter {} { |
| hexio_write test.db 24 [ |
| hexio_render_int32 [expr [hexio_get_int [hexio_read test.db 24 4]] + 1] |
| ] |
| } |
| |
| proc restore_file {} { |
| db close |
| copy_file test.bu test.db |
| sqlite3 db test.db |
| } |
| |
| #------------------------------------------------------------------------- |
| # The following tests, corruptD-1.1.*, focus on the page header field |
| # containing the offset of the first free block in a page. |
| # |
| do_test corruptD-1.1.1 { |
| incr_change_counter |
| hexio_write test.db [expr 1024+1] FFFF |
| catchsql { SELECT * FROM t1 } |
| } {1 {database disk image is malformed}} |
| do_test corruptD-1.1.2 { |
| incr_change_counter |
| hexio_write test.db [expr 1024+1] [hexio_render_int32 1021] |
| catchsql { SELECT * FROM t1 } |
| } {1 {database disk image is malformed}} |
| |
| #------------------------------------------------------------------------- |
| # The following tests, corruptD-1.2.*, focus on the offsets contained |
| # in the first 2 byte of each free-block on the free-list. |
| # |
| do_test corruptD-1.2.1 { |
| restore_file |
| } {} |
| do_test corruptD-1.2.2 { |
| } {} |
| |
| #------------------------------------------------------------------------- |
| # The following tests, corruptD-1.4.*, ... |
| # |
| |
| |
| #------------------------------------------------------------------------- |
| # The following tests, corruptD-1.5.*, focus on the offsets contained |
| # in the cell offset array. |
| # |
| # defragmentPage |
| # |
| |
| finish_test |