Fix a potential buffer overrun in the replace() function. (CVS 3947)

FossilOrigin-Name: b0fb4a3cf6ddbc17ccd0c719b34a720d9090bc93

manifest

@@ -1,5 +1,5 @@
-C Add\smore\scode\sto\senforce\sthe\slimits\sspecified\sin\slimits.h.\s(CVS\s3946)
+C Fix\sa\spotential\sbuffer\soverrun\sin\sthe\sreplace()\sfunction.\s(CVS\s3947)
-D 2007-05-08T13:58:27
+D 2007-05-08T14:39:04
 F Makefile.in 87b200ad9970907f76df734d29dff3d294c10935
 F Makefile.linux-gcc 2d8574d1ba75f129aba2019f0b959db380a90935
 F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@@ -71,7 +71,7 @@ F src/date.c c34a9c86ffd6da4cb3903ea038d977ec539d07e2
 F src/delete.c 5c0d89b3ef7d48fe1f5124bfe8341f982747fe29
 F src/experimental.c 1b2d1a6cd62ecc39610e97670332ca073c50792b
 F src/expr.c 2f0f9f89efe9170e5e6ca5d5e93a9d5896fff5ac
-F src/func.c 755a8c58cd05d290fa2388bd471f8781afe2c1c7
+F src/func.c 72801217dadcbee33a0fda48c02b89db5b5da659
 F src/hash.c 67b23e14f0257b69a3e8aa663e4eeadc1a2b6fd5
 F src/hash.h 1b3f7e2609141fd571f62199fc38687d262e9564
 F src/insert.c e595ca26805dfb3a9ebaabc28e7947c479f3b14d
@@ -247,7 +247,7 @@ F test/fts2k.test 222d0b3bc8667753f18406aaea9906a6098ea016
 F test/fts2l.test 4c53c89ce3919003765ff4fd8d98ecf724d97dd3
 F test/fts2m.test 4b30142ead6f3ed076e880a2a464064c5ad58c51
 F test/fts2n.test a70357e72742681eaebfdbe9007b87ff3b771638
-F test/func.test 5e32fe07bf4113ce2923df28af78c76702f6cd92
+F test/func.test 6f230b25b235cc1afcc7bd5a41baf7317018a8d1
 F test/hook.test 7e7645fd9a033f79cce8fdff151e32715e7ec50a
 F test/icu.test e6bfae7f625c88fd14df6f540fe835bdfc1e4329
 F test/in.test 369cb2aa1eab02296b4ec470732fe8c131260b1d
@@ -485,7 +485,7 @@ F www/tclsqlite.tcl bb0d1357328a42b1993d78573e587c6dcbc964b9
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
 F www/whentouse.tcl fc46eae081251c3c181bd79c5faef8195d7991a5
-P 2f186e916c982cde557e0bc1b925b10e6d58f8a1
+P c59d436095b5258d7132a432c0cb6cd5a7990d85
-R 66a21423994186eccfb2c3232e9829a5
+R e45c28784fb5fd22f2c0e733c939e615
-U drh
+U danielk1977
-Z b93bfcd0453e2fb25e098403e201422f
+Z 3a097658130cbbee5c196715fa819c73

manifest.uuid

@@ -1 +1 @@
-c59d436095b5258d7132a432c0cb6cd5a7990d85
+b0fb4a3cf6ddbc17ccd0c719b34a720d9090bc93

src/func.c

@@ -16,7 +16,7 @@
 ** sqliteRegisterBuildinFunctions() found at the bottom of the file.
 ** All other code has file scope.
 **
-** $Id: func.c,v 1.147 2007/05/08 12:12:17 drh Exp $
+** $Id: func.c,v 1.148 2007/05/08 14:39:04 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -753,7 +753,8 @@ static void replaceFunc(
   if( nPattern>=nRep ){
     nOut = nStr;
   }else{
-    nOut = (nStr/nPattern + 1)*nRep;
+    i64 nOut64 = (i64)(nStr/nPattern + 1) * (i64)nRep;
+    nOut = ((nOut64>SQLITE_MAX_LENGTH) ? SQLITE_MAX_LENGTH : nOut64);
   }
   zOut = sqlite3_malloc(nOut+1);
   if( zOut==0 ) return;
@@ -762,6 +763,11 @@ static void replaceFunc(
     if( zStr[i]!=zPattern[0] || memcmp(&zStr[i], zPattern, nPattern) ){
       zOut[j++] = zStr[i];
     }else{
+      if( (j+nRep+loopLimit-i)>SQLITE_MAX_LENGTH ){
+        sqlite3_result_error(context, "replace() is too large", -1);
+        sqlite3_free(zOut);
+        return;
+      }
       memcpy(&zOut[j], zRep, nRep);
       j += nRep;
       i += nPattern-1;

test/func.test

@@ -11,7 +11,7 @@
 # This file implements regression tests for SQLite library.  The
 # focus of this file is testing built-in functions.
 #
-# $Id: func.test,v 1.64 2007/05/07 16:58:02 danielk1977 Exp $
+# $Id: func.test,v 1.65 2007/05/08 14:39:04 danielk1977 Exp $
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
@@ -333,6 +333,7 @@ do_test func-9.11 {
 do_test func-9.12 {
   execsql {SELECT hex(replace('abcdefg','','12'))}
 } {{}}
+breakpoint
 do_test func-9.13 {
   execsql {SELECT hex(replace('aabcdefg','a','aaa'))}
 } {616161616161626364656667}
@@ -782,6 +783,16 @@ do_test func-21.8 {
   }
 } {0123456789012345678901234567890123456789012345678901234567890123456789}
 
+do_test func-21.9 {
+  # Attempt to exploit a buffer-overflow that at one time existed 
+  # in the REPLACE function. 
+  set ::str "[string repeat A 29998]CC[string repeat A 35537]"
+  set ::rep [string repeat B 65536]
+  execsql {
+    SELECT LENGTH(REPLACE($::str, 'C', $::rep));
+  }
+} [expr 29998 + 2*65536 + 35537]
+
 # Tests for the TRIM, LTRIM and RTRIM functions.
 #
 do_test func-22.1 {