Validate ispell dictionaries more carefully.

Using incorrect, or just mismatched, dictionary and affix files
could result in a crash, due to failure to cross-check offsets
obtained from the file.  Add necessary validation, as well as
some Asserts for future-proofing.

Per bug #16050 from Alexander Lakhin.  Back-patch to 9.6 where the
problem was introduced.

Arthur Zakirov, per initial investigation by Tomas Vondra

Discussion: https://postgr.es/m/16050-024ae722464ab604@postgresql.org
Discussion: https://postgr.es/m/20191013012610.2p2fp3zzpoav7jzf@development

diff --git a/src/backend/tsearch/spell.c b/src/backend/tsearch/spell.c
index 4a9e1396341e2a9b4fafac38c176f7978036a166..07feb68449cdc3e6e48908ca18e8ea82ceefac16 100644 (file)
--- a/src/backend/tsearch/spell.c
+++ b/src/backend/tsearch/spell.c
@@ -458,6 +458,8 @@ IsAffixFlagInUse(IspellDict *Conf, int affix, char *affixflag)
    if (*affixflag == 0)
        return true;
 
+   Assert(affix < Conf->nAffixData);
+
    flagcur = Conf->AffixData[affix];
 
    while (*flagcur)
@@ -1160,13 +1162,17 @@ getAffixFlagSet(IspellDict *Conf, char *s)
                    (errcode(ERRCODE_CONFIG_FILE_ERROR),
                     errmsg("invalid affix alias \"%s\"", s)));
 
-       if (curaffix > 0 && curaffix <= Conf->nAffixData)
+       if (curaffix > 0 && curaffix < Conf->nAffixData)
 
            /*
             * Do not subtract 1 from curaffix because empty string was added
             * in NIImportOOAffixes
             */
            return Conf->AffixData[curaffix];
+       else if (curaffix > Conf->nAffixData)
+           ereport(ERROR,
+                   (errcode(ERRCODE_CONFIG_FILE_ERROR),
+                    errmsg("invalid affix alias \"%s\"", s)));
        else
            return VoidString;
    }
@@ -1556,6 +1562,8 @@ MergeAffix(IspellDict *Conf, int a1, int a2)
 {
    char      **ptr;
 
+   Assert(a1 < Conf->nAffixData && a2 < Conf->nAffixData);
+
    /* Do not merge affix flags if one of affix flags is empty */
    if (*Conf->AffixData[a1] == '\0')
        return a2;
@@ -1598,9 +1606,10 @@ MergeAffix(IspellDict *Conf, int a1, int a2)
 static uint32
 makeCompoundFlags(IspellDict *Conf, int affix)
 {
-   char       *str = Conf->AffixData[affix];
+   Assert(affix < Conf->nAffixData);
 
-   return (getCompoundAffixFlagValue(Conf, str) & FF_COMPOUNDFLAGMASK);
+   return (getCompoundAffixFlagValue(Conf, Conf->AffixData[affix]) &
+           FF_COMPOUNDFLAGMASK);
 }
 
 /*
@@ -1720,6 +1729,16 @@ NISortDictionary(IspellDict *Conf)
                            (errcode(ERRCODE_CONFIG_FILE_ERROR),
                             errmsg("invalid affix alias \"%s\"",
                                    Conf->Spell[i]->p.flag)));
+               if (curaffix < 0 || curaffix >= Conf->nAffixData)
+                   ereport(ERROR,
+                           (errcode(ERRCODE_CONFIG_FILE_ERROR),
+                            errmsg("invalid affix alias \"%s\"",
+                                   Conf->Spell[i]->p.flag)));
+               if (*end != '\0' && !t_isdigit(end) && !t_isspace(end))
+                   ereport(ERROR,
+                           (errcode(ERRCODE_CONFIG_FILE_ERROR),
+                            errmsg("invalid affix alias \"%s\"",
+                                   Conf->Spell[i]->p.flag)));
            }
            else
            {

diff --git a/src/test/regress/expected/tsdicts.out b/src/test/regress/expected/tsdicts.out
index 0744ef803b1c95157f3d1424c267acaaec05474d..eed0d538d0529dca0ee1451c88832087cacb2160 100644 (file)
--- a/src/test/regress/expected/tsdicts.out
+++ b/src/test/regress/expected/tsdicts.out
@@ -383,6 +383,40 @@ SELECT ts_lexize('hunspell_num', 'footballyklubber');
  {foot,ball,klubber}
 (1 row)
 
+-- Test suitability of affix and dict files
+CREATE TEXT SEARCH DICTIONARY hunspell_err (
+                       Template=ispell,
+                       DictFile=ispell_sample,
+                       AffFile=hunspell_sample_long
+);
+ERROR:  invalid affix alias "GJUS"
+CREATE TEXT SEARCH DICTIONARY hunspell_err (
+                       Template=ispell,
+                       DictFile=ispell_sample,
+                       AffFile=hunspell_sample_num
+);
+ERROR:  invalid affix flag "SZ\"
+CREATE TEXT SEARCH DICTIONARY hunspell_invalid_1 (
+                       Template=ispell,
+                       DictFile=hunspell_sample_long,
+                       AffFile=ispell_sample
+);
+CREATE TEXT SEARCH DICTIONARY hunspell_invalid_2 (
+                       Template=ispell,
+                       DictFile=hunspell_sample_long,
+                       AffFile=hunspell_sample_num
+);
+CREATE TEXT SEARCH DICTIONARY hunspell_invalid_3 (
+                       Template=ispell,
+                       DictFile=hunspell_sample_num,
+                       AffFile=ispell_sample
+);
+CREATE TEXT SEARCH DICTIONARY hunspell_err (
+                       Template=ispell,
+                       DictFile=hunspell_sample_num,
+                       AffFile=hunspell_sample_long
+);
+ERROR:  invalid affix alias "302,301,202,303"
 -- Synonym dictionary
 CREATE TEXT SEARCH DICTIONARY synonym (
                        Template=synonym,

diff --git a/src/test/regress/sql/tsdicts.sql b/src/test/regress/sql/tsdicts.sql
index a5a569e1ad4f21e5b13ae33662fd1884163561aa..ed8e2578c558d727035c20499d1b403c85906e06 100644 (file)
--- a/src/test/regress/sql/tsdicts.sql
+++ b/src/test/regress/sql/tsdicts.sql
@@ -96,6 +96,43 @@ SELECT ts_lexize('hunspell_num', 'footballklubber');
 SELECT ts_lexize('hunspell_num', 'ballyklubber');
 SELECT ts_lexize('hunspell_num', 'footballyklubber');
 
+-- Test suitability of affix and dict files
+CREATE TEXT SEARCH DICTIONARY hunspell_err (
+                       Template=ispell,
+                       DictFile=ispell_sample,
+                       AffFile=hunspell_sample_long
+);
+
+CREATE TEXT SEARCH DICTIONARY hunspell_err (
+                       Template=ispell,
+                       DictFile=ispell_sample,
+                       AffFile=hunspell_sample_num
+);
+
+CREATE TEXT SEARCH DICTIONARY hunspell_invalid_1 (
+                       Template=ispell,
+                       DictFile=hunspell_sample_long,
+                       AffFile=ispell_sample
+);
+
+CREATE TEXT SEARCH DICTIONARY hunspell_invalid_2 (
+                       Template=ispell,
+                       DictFile=hunspell_sample_long,
+                       AffFile=hunspell_sample_num
+);
+
+CREATE TEXT SEARCH DICTIONARY hunspell_invalid_3 (
+                       Template=ispell,
+                       DictFile=hunspell_sample_num,
+                       AffFile=ispell_sample
+);
+
+CREATE TEXT SEARCH DICTIONARY hunspell_err (
+                       Template=ispell,
+                       DictFile=hunspell_sample_num,
+                       AffFile=hunspell_sample_long
+);
+
 -- Synonym dictionary
 CREATE TEXT SEARCH DICTIONARY synonym (
                        Template=synonym,