patch 9.1.1131: potential out-of-memory issue in search.c

Problem:  potential out-of-memory issue in search.c
Solution: improve situation and refactor search.c slightly
          (John Marriott)

- In function update_search_stat():
  add a check for a theoretical null pointer reference, set and remember
  the length of lastpat, remove the three calls to STRLEN() and use the
  various string's associated lengths instead, add a check for an
  out-of-memory condition.

- In function search_for_fuzz_match():
  remove a call to strnsave() and thus avoid having to add a check for
  an out-of-memory condition, also replace the call to STRLEN() by
  ml_get_buf_len().

closes: #16689

Signed-off-by: John Marriott <basilisk@internode.on.net>
Signed-off-by: Christian Brabandt <cb@256bit.org>

diff --git a/src/search.c b/src/search.c
index 46fa7b9d994abb553f154cbf2d421cfc80d987e7..3519c32cb6cad4c585f1cd27e7ad367a3ddd3ddb 100644 (file)
--- a/src/search.c
+++ b/src/search.c
@@ -3269,6 +3269,7 @@ update_search_stat(
     static int     last_maxcount = SEARCH_STAT_DEF_MAX_COUNT;
     static int     chgtick = 0;
     static char_u   *lastpat = NULL;
+    static size_t   lastpatlen = 0;
     static buf_T    *lbuf = NULL;
 #ifdef FEAT_RELTIME
     proftime_T  start;
@@ -3295,8 +3296,10 @@ update_search_stat(
     // Unfortunately, there is no MB_STRNICMP function.
     // XXX: above comment should be "no MB_STRCMP function" ?
     if (!(chgtick == CHANGEDTICK(curbuf)
-       && MB_STRNICMP(lastpat, spats[last_idx].pat, STRLEN(lastpat)) == 0
-       && STRLEN(lastpat) == STRLEN(spats[last_idx].pat)
+       && (lastpat != NULL
+           && MB_STRNICMP(lastpat, spats[last_idx].pat, lastpatlen) == 0
+           && lastpatlen == spats[last_idx].patlen
+       )
        && EQUAL_POS(lastpos, *cursor_pos)
        && lbuf == curbuf) || wraparound || cur < 0
            || (maxcount > 0 && cur > maxcount) || recompute)
@@ -3355,7 +3358,11 @@ update_search_stat(
        if (done_search)
        {
            vim_free(lastpat);
-           lastpat = vim_strsave(spats[last_idx].pat);
+           lastpat = vim_strnsave(spats[last_idx].pat, spats[last_idx].patlen);
+           if (lastpat == NULL)
+               lastpatlen = 0;
+           else
+               lastpatlen = spats[last_idx].patlen;
            chgtick = CHANGEDTICK(curbuf);
            lbuf = curbuf;
            lastpos = p;
@@ -5291,8 +5298,6 @@ search_for_fuzzy_match(
     pos_T      circly_end;
     int                found_new_match = FALSE;
     int                looped_around = FALSE;
-    char_u     *next_word_end = NULL;
-    char_u     *match_word = NULL;
 
     if (whole_line)
        current_pos.lnum += dir;
@@ -5330,10 +5335,9 @@ search_for_fuzzy_match(
                    {
                        if (ctrl_x_mode_normal())
                        {
-                           match_word = vim_strnsave(*ptr, *len);
-                           if (STRCMP(match_word, pattern) == 0)
+                           if (STRNCMP(*ptr, pattern, *len) == 0 && pattern[*len] == NUL)
                            {
-                               next_word_end = find_word_start(*ptr + *len);
+                               char_u  *next_word_end = find_word_start(*ptr + *len);
                                if (*next_word_end != NUL && *next_word_end != NL)
                                {
                                    // Find end of the word.
@@ -5355,7 +5359,6 @@ search_for_fuzzy_match(
                                *len = next_word_end - *ptr;
                                current_pos.col = *len;
                            }
-                           vim_free(match_word);
                        }
                        *pos = current_pos;
                        break;
@@ -5369,7 +5372,7 @@ search_for_fuzzy_match(
                    {
                        found_new_match = TRUE;
                        *pos = current_pos;
-                       *len = (int)STRLEN(*ptr);
+                       *len = (int)ml_get_buf_len(buf, current_pos.lnum);
                        break;
                    }
                }

diff --git a/src/version.c b/src/version.c
index 6961a2719a649555fa7f835fe3b5dffac26326a3..8e338f75f5d1d1fed3b35ae3ce35c48c25e28faa 100644 (file)
--- a/src/version.c
+++ b/src/version.c
@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1131,
 /**/
     1130,
 /**/