Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
| Comment: | Prevent the printf formatter from doing large memory allocations - larger than either the size of the static buffer for interfaces like sqlite3_snprintf(), or larger than SQLITE_LIMIT_LENGTH for interfaces that are associated with a database connection. This helps to prevent DOS attacks on products that let hostile sources inject arbitrary SQL. It also helps fuzzers run faster and more effectively. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA3-256: | 179e5d46054e5c86f53a79b7a0823d9a |
| User & Date: | drh 2019-02-01 20:29:04 |
Context
|
2019-02-01
| ||
| 21:08 | Slight adjustment to the printf formatter large memory allocation detector so that it does not overestimate the amount of space needed for oversize %d conversions. check-in: 1aee70d6 user: drh tags: trunk | |
| 20:29 | Prevent the printf formatter from doing large memory allocations - larger than either the size of the static buffer for interfaces like sqlite3_snprintf(), or larger than SQLITE_LIMIT_LENGTH for interfaces that are associated with a database connection. This helps to prevent DOS attacks on products that let hostile sources inject arbitrary SQL. It also helps fuzzers run faster and more effectively. check-in: 179e5d46 user: drh tags: trunk | |
| 18:46 | Performance improvement in the parsing of options to %-formats in the printf implementation. check-in: 40d8f8ae user: drh tags: trunk | |
Changes
Changes to src/printf.c.
151 152 153 154 155 156 157 158 159 160 161 162 163 164 ... 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 ... 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 ... 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 |
return sqlite3_value_double(p->apArg[p->nUsed++]);
}
static char *getTextArg(PrintfArguments *p){
if( p->nArg<=p->nUsed ) return 0;
return (char*)sqlite3_value_text(p->apArg[p->nUsed++]);
}
/*
** On machines with a small stack size, you can redefine the
** SQLITE_PRINT_BUF_SIZE to be something smaller, if desired.
*/
#ifndef SQLITE_PRINT_BUF_SIZE
# define SQLITE_PRINT_BUF_SIZE 70
................................................................................
precision = width-(prefix!=0);
}
if( precision<etBUFSIZE-10-etBUFSIZE/3 ){
nOut = etBUFSIZE;
zOut = buf;
}else{
u64 n = (u64)precision + 10 + precision/3;
zOut = zExtra = sqlite3Malloc( n );
if( zOut==0 ){
setStrAccumError(pAccum, SQLITE_NOMEM);
return;
}
nOut = (int)n;
}
bufpt = &zOut[nOut-1];
if( xtype==etORDINAL ){
static const char zOrd[] = "thstndrd";
int x = (int)(longvalue % 10);
if( x>=4 || (longvalue/10)%10==1 ){
................................................................................
flag_rtz = flag_altform2;
}
if( xtype==etEXP ){
e2 = 0;
}else{
e2 = exp;
}
if( MAX(e2,0)+(i64)precision+(i64)width > etBUFSIZE - 15 ){
bufpt = zExtra
= sqlite3Malloc( MAX(e2,0)+(i64)precision+(i64)width+15 );
if( bufpt==0 ){
setStrAccumError(pAccum, SQLITE_NOMEM);
return;
}
}
zOut = bufpt;
nsd = 16 + flag_altform2*10;
flag_dp = (precision>0 ?1:0) | flag_alternateform | flag_altform2;
/* The sign in front of the number */
if( prefix ){
................................................................................
if( flag_altform2 && (ch&0xc0)==0xc0 ){
while( (escarg[i+1]&0xc0)==0x80 ){ i++; }
}
}
needQuote = !isnull && xtype==etSQLESCAPE2;
n += i + 3;
if( n>etBUFSIZE ){
bufpt = zExtra = sqlite3Malloc( n );
if( bufpt==0 ){
setStrAccumError(pAccum, SQLITE_NOMEM);
return;
}
}else{
bufpt = buf;
}
j = 0;
if( needQuote ) bufpt[j++] = q;
k = i;
for(i=0; i<k; i++){
|
> > > > > > > > > > > > > > > > > > > > > | | < < < | | | | | | | | < < < |
151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 ... 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 ... 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 ... 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 |
return sqlite3_value_double(p->apArg[p->nUsed++]);
}
static char *getTextArg(PrintfArguments *p){
if( p->nArg<=p->nUsed ) return 0;
return (char*)sqlite3_value_text(p->apArg[p->nUsed++]);
}
/*
** Allocate memory for a temporary buffer needed for printf rendering.
**
** If the requested size of the temp buffer is larger than the size
** of the output buffer in pAccum, then cause an SQLITE_TOOBIG error.
** Do the size check before the memory allocation to prevent rogue
** SQL from requesting large allocations using the precision or width
** field of the printf() function.
*/
static char *printfTempBuf(sqlite3_str *pAccum, sqlite3_int64 n){
char *z;
if( n>pAccum->nAlloc && n>pAccum->mxAlloc ){
setStrAccumError(pAccum, SQLITE_TOOBIG);
return 0;
}
z = sqlite3DbMallocRaw(pAccum->db, n);
if( z==0 ){
setStrAccumError(pAccum, SQLITE_NOMEM);
}
return z;
}
/*
** On machines with a small stack size, you can redefine the
** SQLITE_PRINT_BUF_SIZE to be something smaller, if desired.
*/
#ifndef SQLITE_PRINT_BUF_SIZE
# define SQLITE_PRINT_BUF_SIZE 70
................................................................................
precision = width-(prefix!=0);
}
if( precision<etBUFSIZE-10-etBUFSIZE/3 ){
nOut = etBUFSIZE;
zOut = buf;
}else{
u64 n = (u64)precision + 10 + precision/3;
zOut = zExtra = printfTempBuf(pAccum, n);
if( zOut==0 ) return;
nOut = (int)n;
}
bufpt = &zOut[nOut-1];
if( xtype==etORDINAL ){
static const char zOrd[] = "thstndrd";
int x = (int)(longvalue % 10);
if( x>=4 || (longvalue/10)%10==1 ){
................................................................................
flag_rtz = flag_altform2;
}
if( xtype==etEXP ){
e2 = 0;
}else{
e2 = exp;
}
{
i64 szBufNeeded; /* Size of a temporary buffer needed */
szBufNeeded = MAX(e2,0)+(i64)precision+(i64)width+15;
if( szBufNeeded > etBUFSIZE ){
bufpt = zExtra = printfTempBuf(pAccum, szBufNeeded);
if( bufpt==0 ) return;
}
}
zOut = bufpt;
nsd = 16 + flag_altform2*10;
flag_dp = (precision>0 ?1:0) | flag_alternateform | flag_altform2;
/* The sign in front of the number */
if( prefix ){
................................................................................
if( flag_altform2 && (ch&0xc0)==0xc0 ){
while( (escarg[i+1]&0xc0)==0x80 ){ i++; }
}
}
needQuote = !isnull && xtype==etSQLESCAPE2;
n += i + 3;
if( n>etBUFSIZE ){
bufpt = zExtra = printfTempBuf(pAccum, n);
if( bufpt==0 ) return;
}else{
bufpt = buf;
}
j = 0;
if( needQuote ) bufpt[j++] = q;
k = i;
for(i=0; i<k; i++){
|