| Bug #86291 | MYSQL_DATA_TRUNCATED reported when buffer large enough | ||
|---|---|---|---|
| Submitted: | 12 May 2017 3:38 | Modified: | 7 Jul 2017 4:46 |
| Reporter: | Francois Lamoureux | Email Updates: | |
| Status: | No Feedback | Impact on me: | |
| Category: | MySQL Server: C API (client library) | Severity: | S3 (Non-critical) |
| Version: | 5.7.18 | OS: | Ubuntu (16.04) |
| Assigned to: | Assigned Account | CPU Architecture: | Any |
[14 May 2017 20:04]
Francois Lamoureux
On a different table I also get the same sort of error. I even went as far as allocating double the column lenght.
Given this FOR statement:
-------
for (int x=0; x<mysql_num_fields(metadata); x++) {
MYSQL_FIELD *field = mysql_fetch_field_direct(metadata, x);
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, " error: %4s, length: %5lu, buffer_length: %5lu, column size: %5lu",
bind_results[x].error_value ? "true" : "no",
(unsigned long) *bind_results[x].length,
bind_results[x].buffer_length,
field->length);
}
-------
This is what I got
-------
error: no, length: 4, buffer_length: 22, column size: 11
error: no, length: 24, buffer_length: 25, column size: 24
error: no, length: 44, buffer_length: 45, column size: 44
error: no, length: 44, buffer_length: 10001, column size: 10000
error: true, length: 44, buffer_length: 101, column size: 100
error: true, length: 4, buffer_length: 22, column size: 11
error: no, length: 40, buffer_length: 40, column size: 23
error: true, length: 0, buffer_length: 37, column size: 36
error: true, length: 4, buffer_length: 22, column size: 11
error: true, length: 9, buffer_length: 46, column size: 45
error: true, length: 28, buffer_length: 257, column size: 256
error: true, length: 36, buffer_length: 37, column size: 36
error: true, length: 10, buffer_length: 51, column size: 50
error: true, length: 3, buffer_length: 46, column size: 45
error: true, length: 4, buffer_length: 22, column size: 11
error: true, length: 3, buffer_length: 46, column size: 45
error: true, length: 10, buffer_length: 16, column size: 15
error: no, length: 40, buffer_length: 40, column size: 23
error: no, length: 40, buffer_length: 40, column size: 23
error: true, length: 40, buffer_length: 40, column size: 23
error: true, length: 40, buffer_length: 40, column size: 23
error: no, length: 40, buffer_length: 40, column size: 23
error: true, length: 40, buffer_length: 40, column size: 23
error: no, length: 8, buffer_length: 30, column size: 15
error: no, length: 8, buffer_length: 30, column size: 15
error: no, length: 8, buffer_length: 30, column size: 15
error: no, length: 8, buffer_length: 30, column size: 15
error: no, length: 8, buffer_length: 30, column size: 15
error: true, length: 8, buffer_length: 30, column size: 15
-------
[19 May 2017 11:35]
Chiranjeevi Battula
Hello Francois, Thank you for the bug report. Could you please provide repeatable test case (exact steps/sample code, create table statement/database details etc. - please make it as private if you prefer) to confirm this issue at our end? Thanks, Chiranjeevi.
[7 Jun 2017 0:25]
Francois Lamoureux
Hi, sorry, I haven't forgotten about you nor this bug. I'll see if I can strip down my DB and program to the bare minimum.
[8 Jul 2017 1:00]
Bugs System
No feedback was provided for this bug for over a month, so it is being suspended automatically. If you are able to provide the information that was originally requested, please do so and change the status of the bug back to "Open".
Description: MYSQL_DATA_TRUNCATED is returned after mysql_stmt_fetch() even though all bind_results parameters have been allocated enough memory. Output from code below: ----------------------- allocating 51 for FIELD1 allocating 37 for FIELD2 allocating 46 for FIELD3 allocating 65 for FIELD4 allocating 1 for F5 allocating 8 for F6 allocating 8 for F7 allocating 8 for F8 Data truncated error: no, length: 8, buffer_length: 51, error: true, length: 36, buffer_length: 37, error: no, length: 15, buffer_length: 46, error: no, length: 9, buffer_length: 65, error: no, length: 1, buffer_length: 1, error: no, length: 4, buffer_length: 8, error: no, length: 4, buffer_length: 8, error: true, length: 4, buffer_length: 8, ------------------------ We can clearly see above that the two fields where error is set to true (which triggered the MYSQL_DATA_TRUNCATED return code) have been allocated large enough. How to repeat: Using a View descibed as such: =========================================== Field type NULL Default FIELD1 varchar(50) NO FIELD2 varchar(36) NO uuid() FIELD3 varchar(45) YES FIELD4 varchar(64) YES F5 tinyint(1) YES 1 F6 int(11) YES -1 F7 int(11) YES -1 F8 int(11) YES -1 And with this single row returned from the view: ================================================= FIELD1 FIELD2 FIELD3 FIELD4 F5 F6 F8 F9 aaaaaaaa cc2361a2-34f4-42b7-8b5c-1a59e9dc423b aaaaaaaaaaaaaaa aaaaaaaaa 1 -1 -1 -1 ================================================== Then calling the do_something() method below will reproduce the output from the defect description: -------------------- apr_hash_t *prepare_bind_results(MYSQL_RES *metadata, MYSQL_BIND bind_result[]) { apr_hash_t *ret = apr_hash_make(r->pool); MYSQL_FIELD *field; for(int i = 0; i < mysql_num_fields(metadata); i++) { field = mysql_fetch_field_direct(metadata, i); bind_result[i].buffer_type = field->type; bind_result[i].length = apr_pcalloc(r->pool, sizeof(unsigned long)); *bind_result[i].length = 0; switch (field->type) { case (MYSQL_TYPE_TINY): bind_result[i].buffer = (signed char *) apr_pcalloc(r->pool, sizeof(signed char)); bind_result[i].buffer_length = sizeof(signed char); break; case (MYSQL_TYPE_LONG): bind_result[i].buffer = (long *) apr_pcalloc(r->pool, sizeof(long)); bind_result[i].buffer_length = sizeof(long); break; case (MYSQL_TYPE_LONGLONG): bind_result[i].buffer = (long long*) apr_pcalloc(r->pool, sizeof(long long)); bind_result[i].buffer_length = sizeof(long long); break; case (MYSQL_TYPE_STRING): case (MYSQL_TYPE_VARCHAR): case (MYSQL_TYPE_VAR_STRING): bind_result[i].buffer = apr_pcalloc(r->pool, sizeof(char) * (field->length + 1)); bind_result[i].buffer_length = sizeof(char) * (field->length + 1); break; case (MYSQL_TYPE_TIME): case (MYSQL_TYPE_DATE): case (MYSQL_TYPE_DATETIME): case (MYSQL_TYPE_TIMESTAMP): bind_result[i].buffer = (MYSQL_TIME *) apr_pcalloc(r->pool, sizeof(MYSQL_TIME)); bind_result[i].buffer_length = sizeof(MYSQL_TIME); break; default: ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "Database column type for column [%s] is not handled (enum value: %d)!!! (%s:%d)", field->name, field->type, __FILE__, __LINE__); } ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r, "allocating %lu for %s", bind_result[i].buffer_length, field->name ); bind_result[i].is_null = apr_pcalloc(r->pool, sizeof(my_bool)); bind_result[i].error = apr_pcalloc(r->pool, sizeof(my_bool)); apr_hash_set(ret, apr_pstrdup(r->pool, field->name), APR_HASH_KEY_STRING, &bind_result[i]); } return ret; } bool do_something() { bool ret = false; MYSQL_STMT *stmt = NULL; MYSQL_BIND bind_select[1]; MYSQL_RES *metadata = NULL; char *sql = apr_pstrdup(r->pool, "select * from my_view where FIELD1 = ?"); memset(bind_select, 0, sizeof(bind_select)); bind_select[0].buffer_type= MYSQL_TYPE_STRING; bind_select[0].buffer= (char *) "aaaaaaaa"; bind_select[0].buffer_length=strlen("aaaaaaaa"); ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r, "SQL: %s", sql); if (!(stmt = mysql_stmt_init(&mysql))) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "mysql_stmt_init(), out of memory"); }else if (mysql_stmt_prepare(stmt, sql, strlen(sql))) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "mysql_stmt_prepare() failed with %s", mysql_stmt_error(stmt)); }else if (mysql_stmt_bind_param(stmt, bind_select)) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "mysql_stmt_bind_param() failed with %s", mysql_stmt_error(stmt)); } else if (!(metadata = mysql_stmt_result_metadata(stmt))){ ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "mysql_stmt_execute() failed with %s", mysql_stmt_error(stmt)); } else { int field_count = mysql_num_fields(metadata); MYSQL_BIND bind_results[field_count]; apr_hash_t *hash_bind_results = prepare_bind_results(metadata, bind_results); int db_ret = 0; if (mysql_stmt_bind_result(stmt, bind_results)) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "mysql_stmt_bind_result() failed with %s", mysql_stmt_error(stmt)); }else if (mysql_stmt_execute(stmt)) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "mysql_stmt_execute() failed with %s", mysql_stmt_error(stmt)); } else if (mysql_stmt_store_result(stmt)) { // This will force fetching all rows from the server in one shot, preventing back and forth ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "mysql_stmt_store_result() failed with %s", mysql_stmt_error(stmt)); }else if ((db_ret = mysql_stmt_fetch(stmt)) == 0) { ret = true; // whatever... }else if (db_ret == MYSQL_DATA_TRUNCATED) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "Data truncated!!!"); for (int x=0; x<field_count; x++) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "error: %s, length: %lu, buffer_length: %lu, ", bind_results[x].error_value ? "true" : "no", (unsigned long) *bind_results[x].length, bind_results[x].buffer_length); } }else if (db_ret == MYSQL_NO_DATA) { ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "No rows returned"); }else{ ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "Error: %s", mysql_stmt_error(stmt)); } } if (stmt) { mysql_stmt_close(stmt); } return ret; }