1From b98375f9df0b024857c03c03bc3e73e8ced8d772 Mon Sep 17 00:00:00 2001
2From: Nayuta Yanagisawa <nayuta.yanagisawa@hey.com>
3Date: Tue, 27 Sep 2022 15:22:57 +0900
4Subject: [PATCH] MDEV-29644 a potential bug of null pointer dereference in
5 spider_db_mbase::print_warnings()
6
7The function spider_db_mbase::print_warnings() can potentially result
8in a null pointer dereference.
9
10Remove the null pointer dereference by cleaning up the function.
11
12Some small changes to the original commit
13422fb63a9bbee35c50b6c7be19d199afe0bc98fa.
14
15CVE: CVE-2022-47015
16
17Upstream-Status: Backport [https://github.com/MariaDB/server/commit/b98375f9df0]
18
19Co-Authored-By: Yuchen Pei <yuchen.pei@mariadb.com>
20Signed-off-by: Mingli Yu <mingli.yu@windriver.com>
21---
22 .../spider/bugfix/r/mdev_29644.result         |  41 ++++++
23 .../mysql-test/spider/bugfix/t/mdev_29644.cnf |   3 +
24 .../spider/bugfix/t/mdev_29644.test           |  56 ++++++++
25 storage/spider/spd_db_mysql.cc                | 124 ++++++++----------
26 storage/spider/spd_db_mysql.h                 |   2 +-
27 5 files changed, 154 insertions(+), 72 deletions(-)
28 create mode 100644 storage/spider/mysql-test/spider/bugfix/r/mdev_29644.result
29 create mode 100644 storage/spider/mysql-test/spider/bugfix/t/mdev_29644.cnf
30 create mode 100644 storage/spider/mysql-test/spider/bugfix/t/mdev_29644.test
31
32diff --git a/storage/spider/mysql-test/spider/bugfix/r/mdev_29644.result b/storage/spider/mysql-test/spider/bugfix/r/mdev_29644.result
33new file mode 100644
34index 00000000000..b52cecc5bb7
35--- /dev/null
36+++ b/storage/spider/mysql-test/spider/bugfix/r/mdev_29644.result
37@@ -0,0 +1,41 @@
38+#
39+# MDEV-29644 a potential bug of null pointer dereference in spider_db_mbase::print_warnings()
40+#
41+for master_1
42+for child2
43+child2_1
44+child2_2
45+child2_3
46+for child3
47+connection child2_1;
48+CREATE DATABASE auto_test_remote;
49+USE auto_test_remote;
50+CREATE TABLE tbl_a (
51+a CHAR(5)
52+) ENGINE=InnoDB DEFAULT CHARSET=utf8;
53+SET GLOBAL sql_mode='';
54+connection master_1;
55+CREATE DATABASE auto_test_local;
56+USE auto_test_local;
57+CREATE TABLE tbl_a (
58+a CHAR(255)
59+) ENGINE=Spider DEFAULT CHARSET=utf8 COMMENT='table "tbl_a", srv "s_2_1"';
60+SET sql_mode='';
61+INSERT INTO tbl_a VALUES ("this will be truncated");
62+NOT FOUND /\[WARN SPIDER RESULT\].* Warning 1265 Data truncated for column 'a' at row 1.*/ in mysqld.1.1.err
63+SET GLOBAL spider_log_result_errors=4;
64+INSERT INTO tbl_a VALUES ("this will be truncated");
65+FOUND 1 /\[WARN SPIDER RESULT\].* Warning 1265 Data truncated for column 'a' at row 1.*/ in mysqld.1.1.err
66+connection master_1;
67+SET GLOBAL spider_log_result_errors=DEFAULT;
68+SET sql_mode=DEFAULT;
69+DROP DATABASE IF EXISTS auto_test_local;
70+connection child2_1;
71+SET GLOBAL sql_mode=DEFAULT;
72+DROP DATABASE IF EXISTS auto_test_remote;
73+for master_1
74+for child2
75+child2_1
76+child2_2
77+child2_3
78+for child3
79diff --git a/storage/spider/mysql-test/spider/bugfix/t/mdev_29644.cnf b/storage/spider/mysql-test/spider/bugfix/t/mdev_29644.cnf
80new file mode 100644
81index 00000000000..05dfd8a0bce
82--- /dev/null
83+++ b/storage/spider/mysql-test/spider/bugfix/t/mdev_29644.cnf
84@@ -0,0 +1,3 @@
85+!include include/default_mysqld.cnf
86+!include ../my_1_1.cnf
87+!include ../my_2_1.cnf
88diff --git a/storage/spider/mysql-test/spider/bugfix/t/mdev_29644.test b/storage/spider/mysql-test/spider/bugfix/t/mdev_29644.test
89new file mode 100644
90index 00000000000..3a8fbb251e1
91--- /dev/null
92+++ b/storage/spider/mysql-test/spider/bugfix/t/mdev_29644.test
93@@ -0,0 +1,56 @@
94+--echo #
95+--echo # MDEV-29644 a potential bug of null pointer dereference in spider_db_mbase::print_warnings()
96+--echo #
97+
98+# The test case below does not cause the potential null pointer dereference.
99+# It is just for checking spider_db_mbase::fetch_and_print_warnings() works.
100+
101+--disable_query_log
102+--disable_result_log
103+--source ../../t/test_init.inc
104+--enable_result_log
105+--enable_query_log
106+
107+--connection child2_1
108+CREATE DATABASE auto_test_remote;
109+USE auto_test_remote;
110+eval CREATE TABLE tbl_a (
111+    a CHAR(5)
112+) $CHILD2_1_ENGINE $CHILD2_1_CHARSET;
113+
114+SET GLOBAL sql_mode='';
115+
116+--connection master_1
117+CREATE DATABASE auto_test_local;
118+USE auto_test_local;
119+eval CREATE TABLE tbl_a (
120+    a CHAR(255)
121+) $MASTER_1_ENGINE $MASTER_1_CHARSET COMMENT='table "tbl_a", srv "s_2_1"';
122+
123+SET sql_mode='';
124+
125+let SEARCH_FILE= $MYSQLTEST_VARDIR/log/mysqld.1.1.err;
126+let SEARCH_PATTERN= \[WARN SPIDER RESULT\].* Warning 1265 Data truncated for column 'a' at row 1.*;
127+
128+INSERT INTO tbl_a VALUES ("this will be truncated");
129+--source include/search_pattern_in_file.inc # should not find
130+
131+SET GLOBAL spider_log_result_errors=4;
132+
133+INSERT INTO tbl_a VALUES ("this will be truncated");
134+--source include/search_pattern_in_file.inc # should find
135+
136+--connection master_1
137+SET GLOBAL spider_log_result_errors=DEFAULT;
138+SET sql_mode=DEFAULT;
139+DROP DATABASE IF EXISTS auto_test_local;
140+
141+--connection child2_1
142+SET GLOBAL sql_mode=DEFAULT;
143+DROP DATABASE IF EXISTS auto_test_remote;
144+
145+--disable_query_log
146+--disable_result_log
147+--source ../t/test_deinit.inc
148+--enable_query_log
149+--enable_result_log
150diff --git a/storage/spider/spd_db_mysql.cc b/storage/spider/spd_db_mysql.cc
151index d377d2bd807..bc8383017f7 100644
152--- a/storage/spider/spd_db_mysql.cc
153+++ b/storage/spider/spd_db_mysql.cc
154@@ -2207,7 +2207,7 @@ int spider_db_mbase::exec_query(
155         db_conn->affected_rows, db_conn->insert_id,
156         db_conn->server_status, db_conn->warning_count);
157       if (spider_param_log_result_errors() >= 3)
158-        print_warnings(l_time);
159+        fetch_and_print_warnings(l_time);
160     } else if (log_result_errors >= 4)
161     {
162       time_t cur_time = (time_t) time((time_t*) 0);
163@@ -2289,81 +2289,63 @@ bool spider_db_mbase::is_xa_nota_error(
164   DBUG_RETURN(xa_nota);
165 }
166
167-int spider_db_mbase::print_warnings(
168-  struct tm *l_time
169-) {
170+int spider_db_mbase::fetch_and_print_warnings(struct tm *l_time)
171+{
172   int error_num = 0;
173-  DBUG_ENTER("spider_db_mbase::print_warnings");
174+  DBUG_ENTER("spider_db_mbase::fetch_and_print_warnings");
175   DBUG_PRINT("info",("spider this=%p", this));
176-  if (db_conn->status == MYSQL_STATUS_READY)
177+
178+  if (spider_param_dry_access() || db_conn->status != MYSQL_STATUS_READY ||
179+      db_conn->server_status & SERVER_MORE_RESULTS_EXISTS ||
180+      !db_conn->warning_count)
181+    DBUG_RETURN(0);
182+
183+  if (mysql_real_query(db_conn, SPIDER_SQL_SHOW_WARNINGS_STR,
184+                       SPIDER_SQL_SHOW_WARNINGS_LEN))
185+    DBUG_RETURN(0);
186+
187+  MYSQL_RES *res= mysql_store_result(db_conn);
188+  if (!res)
189+    DBUG_RETURN(0);
190+
191+  uint num_fields= mysql_num_fields(res);
192+  if (num_fields != 3)
193   {
194-    if (
195-#if MYSQL_VERSION_ID < 50500
196-      !(db_conn->last_used_con->server_status & SERVER_MORE_RESULTS_EXISTS) &&
197-      db_conn->last_used_con->warning_count
198-#else
199-      !(db_conn->server_status & SERVER_MORE_RESULTS_EXISTS) &&
200-      db_conn->warning_count
201-#endif
202-    ) {
203-      if (
204-        spider_param_dry_access() ||
205-        !mysql_real_query(db_conn, SPIDER_SQL_SHOW_WARNINGS_STR,
206-          SPIDER_SQL_SHOW_WARNINGS_LEN)
207-      ) {
208-        MYSQL_RES *res = NULL;
209-        MYSQL_ROW row = NULL;
210-        uint num_fields;
211-        if (
212-          spider_param_dry_access() ||
213-          !(res = mysql_store_result(db_conn)) ||
214-          !(row = mysql_fetch_row(res))
215-        ) {
216-          if (mysql_errno(db_conn))
217-          {
218-            if (res)
219-              mysql_free_result(res);
220-            DBUG_RETURN(0);
221-          }
222-          /* no record is ok */
223-        }
224-        num_fields = mysql_num_fields(res);
225-        if (num_fields != 3)
226-        {
227-          mysql_free_result(res);
228-          DBUG_RETURN(0);
229-        }
230-        if (l_time)
231-        {
232-          while (row)
233-          {
234-            fprintf(stderr, "%04d%02d%02d %02d:%02d:%02d [WARN SPIDER RESULT] "
235-              "from [%s] %ld to %ld: %s %s %s\n",
236+    mysql_free_result(res);
237+    DBUG_RETURN(0);
238+  }
239+
240+  MYSQL_ROW row= mysql_fetch_row(res);
241+  if (l_time)
242+  {
243+    while (row)
244+    {
245+      fprintf(stderr,
246+              "%04d%02d%02d %02d:%02d:%02d [WARN SPIDER RESULT] from [%s] %ld "
247+              "to %ld: %s %s %s\n",
248               l_time->tm_year + 1900, l_time->tm_mon + 1, l_time->tm_mday,
249-              l_time->tm_hour, l_time->tm_min, l_time->tm_sec,
250-              conn->tgt_host, (ulong) db_conn->thread_id,
251-              (ulong) current_thd->thread_id, row[0], row[1], row[2]);
252-            row = mysql_fetch_row(res);
253-          }
254-        } else {
255-          while (row)
256-          {
257-            DBUG_PRINT("info",("spider row[0]=%s", row[0]));
258-            DBUG_PRINT("info",("spider row[1]=%s", row[1]));
259-            DBUG_PRINT("info",("spider row[2]=%s", row[2]));
260-            longlong res_num =
261-              (longlong) my_strtoll10(row[1], (char**) NULL, &error_num);
262-            DBUG_PRINT("info",("spider res_num=%lld", res_num));
263-            my_printf_error((int) res_num, row[2], MYF(0));
264-            error_num = (int) res_num;
265-            row = mysql_fetch_row(res);
266-          }
267-        }
268-        if (res)
269-          mysql_free_result(res);
270-      }
271+              l_time->tm_hour, l_time->tm_min, l_time->tm_sec, conn->tgt_host,
272+              (ulong) db_conn->thread_id, (ulong) current_thd->thread_id, row[0],
273+              row[1], row[2]);
274+      row= mysql_fetch_row(res);
275+    }
276+  } else {
277+    while (row)
278+    {
279+      DBUG_PRINT("info",("spider row[0]=%s", row[0]));
280+      DBUG_PRINT("info",("spider row[1]=%s", row[1]));
281+      DBUG_PRINT("info",("spider row[2]=%s", row[2]));
282+      longlong res_num =
283+        (longlong) my_strtoll10(row[1], (char**) NULL, &error_num);
284+      DBUG_PRINT("info",("spider res_num=%lld", res_num));
285+      my_printf_error((int) res_num, row[2], MYF(0));
286+      error_num = (int) res_num;
287+      row = mysql_fetch_row(res);
288     }
289   }
290+
291+  mysql_free_result(res);
292+
293   DBUG_RETURN(error_num);
294 }
295
296@@ -14668,7 +14650,7 @@ int spider_mbase_handler::show_table_status(
297       DBUG_RETURN(error_num);
298     }
299   }
300-  if ((error_num = ((spider_db_mbase *) conn->db_conn)->print_warnings(NULL)))
301+  if ((error_num = ((spider_db_mbase *) conn->db_conn)->fetch_and_print_warnings(NULL)))
302   {
303     DBUG_RETURN(error_num);
304   }
305diff --git a/storage/spider/spd_db_mysql.h b/storage/spider/spd_db_mysql.h
306index e90461ea278..a2012352f21 100644
307--- a/storage/spider/spd_db_mysql.h
308+++ b/storage/spider/spd_db_mysql.h
309@@ -442,7 +442,7 @@ class spider_db_mbase: public spider_db_conn
310   bool is_xa_nota_error(
311     int error_num
312   );
313-  int print_warnings(
314+  int fetch_and_print_warnings(
315     struct tm *l_time
316   );
317   spider_db_result *store_result(
318--
3192.25.1
320
321