Limit the size of input strings to the (disused) spellfix extension

to avoid excessive runtime and integer overflows.

FossilOrigin-Name: 2a8951b548a9408df300d238a9fea313268a30c322f0efc0b233bdd3e71a7f9d

ext/misc/spellfix.c

@@ -1008,6 +1008,8 @@ static int editDist3Core(
   unsigned int stackSpace[SQLITE_SPELLFIX_STACKALLOC_SZ/sizeof(unsigned int)];
 
   /* allocate the Wagner matrix and the aTo[] array for the TO string */
+  if( n2>10000 ) return -2;
+  if( f.n>10000 ) return -2;
   n = (f.n+1)*(n2+1);
   n = (n+1)&~1;
   nByte = n*sizeof(m[0]) + sizeof(a2[0])*n2;
@@ -1198,6 +1200,8 @@ static void editDist3SqlFunc(
     editDist3FromStringDelete(pFrom);
     if( dist==(-1) ){
       sqlite3_result_error_nomem(context);
+    }else if( dist==(-2) ){
+      sqlite3_result_error_toobig(context);
     }else{
       sqlite3_result_int(context, dist);
     }

manifest

@@ -1,5 +1,5 @@
-C Fix\sa\sNULL\spointer\sdereference\sin\sthe\sobscure\s(and\sunused)\sprefixes\nextension,\swhich\sI\shad\sforgotten\seven\sexisted.
-D 2026-05-19T10:30:29.681
+C Limit\sthe\ssize\sof\sinput\sstrings\sto\sthe\s(disused)\sspellfix\sextension\nto\savoid\sexcessive\sruntime\sand\sinteger\soverflows.
+D 2026-05-19T10:33:53.258
 F .fossil-settings/binary-glob 61195414528fb3ea9693577e1980230d78a1f8b0a54c78cf1b9b24d0a409ed6a x
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
@@ -398,7 +398,7 @@ F ext/misc/series.c 496f43bac9bad2ee2cea63fb5212036f30ad3003b4cd317d5c2d6f3ad7c7
 F ext/misc/sha1.c 8bf60344c11a525384c2efd1ae77f160b06be336db679effaadf292d4b41451c
 F ext/misc/shathree.c fd22d70620f86a0467acfdd3acd8435d5cb54eb1e2d9ff36ae44e389826993df
 F ext/misc/showauth.c 732578f0fe4ce42d577e1c86dc89dd14a006ab52
-F ext/misc/spellfix.c 693c8fd3293087fa821322967a97e59dfa24051e5d2ca7fa85790a4034db6fa4
+F ext/misc/spellfix.c 33c92014c4662c2678ec01fd7dfa622aeff2f6f0f7821f643b331d4cabac2c7e
 F ext/misc/sqlar.c 97c100b010159c08a7a9acd8eb1ea510a5522e64741aaafcd7b6c629de682edc
 F ext/misc/sqlite3_stdio.c b43a0f530c6f0fb3d41d9af8c0b40f3f71198a1db55ab8ffffbef5c8cc329d22
 F ext/misc/sqlite3_stdio.h 27a4ecea47e61bc9574ccdf2806f468afe23af2f95028c9b689bfa08ab1ce99f
@@ -1670,7 +1670,7 @@ F test/speedtest1.c 6c01252e66f46de0b6b8d5316e03521e2151782104f3608c10262aa5dce8
 F test/spellfix.test 951a6405d49d1a23d6b78027d3877b4a33eeb8221dcab5704b499755bb4f552e
 F test/spellfix2.test dfc8f519a3fc204cb2dfa8b4f29821ae90f6f8c3
 F test/spellfix3.test 0f9efaaa502a0e0a09848028518a6fb096c8ad33
-F test/spellfix4.test 51c7c26514ade169855c66bcf130bd5acfb4d7fd090cc624645ab275ae6a41fb
+F test/spellfix4.test 7c56a09de68b95051ef0627fe235e514efbba2aa816dc2a9c5c670d98877e632
 F test/sqldiff1.test 1b7ab4f312442c5cc6b3a5f299fa8ca051416d1dd173cb1126fd51bf64f2c3fb
 F test/sqllimits1.test 408131e4975d61868711c83f101a56d4602313cc5cae88d3eee81c1da364fd89
 F test/sqllog.test 6af6cb0b09f4e44e1917e06ce85be7670302517a
@@ -2198,9 +2198,9 @@ F tool/warnings-clang.sh bbf6a1e685e534c92ec2bfba5b1745f34fb6f0bc2a362850723a9ee
 F tool/warnings.sh a554d13f6e5cf3760f041b87939e3d616ec6961859c3245e8ef701d1eafc2ca2
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
 F tool/winmain.c 00c8fb88e365c9017db14c73d3c78af62194d9644feaf60e220ab0f411f3604c
-P 9bf2f4ca8f3d0cce2ac0bf3742a04a83460d309bd8864bd414946d35106014a9
-Q +4880adc053b0f21633936347fd5610e4338b15da39607d8ba5a6b32d1516e8cb
-R 3774ec557a88b5c578c28228d99536f7
+P 24b8ecd17f70f222c40aa91382515a7d0d0b82c882498ae0714818d672806e7f
+Q +4b16b80cf2e26c41f0828d65883145dc81c0987110c3f04a864cec43e7c418e5
+R 6f5606fdbd8f4c5422503bb256f4ddcd
 U drh
-Z 4d02eabbd2e500772250f8e258de799f
+Z 6768569daddda80128545c4db75384d8
 # Remove this line to create a well-formed Fossil manifest.

manifest.uuid

@@ -1 +1 @@
-24b8ecd17f70f222c40aa91382515a7d0d0b82c882498ae0714818d672806e7f
+2a8951b548a9408df300d238a9fea313268a30c322f0efc0b233bdd3e71a7f9d

test/spellfix4.test

@@ -350,4 +350,14 @@ do_execsql_test 320 {
   )
 } {69d0a31872203a775e19325ea98cd053}
 
+do_catchsql_test 400 {
+  SELECT editdist3(format('%.10001c','x'),'abc');
+} {1 {string or blob too big}}
+do_catchsql_test 401 {
+  SELECT editdist3('xxxabc',format('%.10001c','x'));
+} {1 {string or blob too big}}
+do_catchsql_test 410 {
+  SELECT editdist3(format('abc%.9997c','x'),format('abc%.9997c','x'));
+} {0 0}
+
 finish_test