patch 9.0.2108: [security]: overflow with count for :s command

Problem:  [security]: overflow with count for :s command
Solution: Abort the :s command if the count is too large

If the count after the :s command is larger than what fits into a
(signed) long variable, abort with e_value_too_large.

Adds a test with INT_MAX as count and verify it correctly fails.

It seems the return value on Windows using mingw compiler wraps around,
so the initial test using :s/./b/9999999999999999999999999990 doesn't
fail there, since the count is wrapping around several times and finally
is no longer larger than 2147483647. So let's just use 2147483647 in the
test, which hopefully will always cause a failure

Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/doc/change.txt

@@ -1,4 +1,4 @@
-*change.txt*    For Vim version 9.0.  Last change: 2023 Sep 19
+*change.txt*    For Vim version 9.0.  Last change: 2023 Nov 15
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -644,9 +644,9 @@ For other systems the tmpnam() library function is used.
 			current line only.  When [count] is given, replace in
 			[count] lines, starting with the last line in [range].
 			When [range] is omitted start in the current line.
-							*E939*
-			[count] must be a positive number.  Also see
-			|cmdline-ranges|.
+							*E939* *E1510*
+			[count] must be a positive number (max 2147483647)
+			Also see |cmdline-ranges|.
 
 			See |:s_flags| for [flags].
 			The delimiter doesn't need to be /, see

runtime/doc/cmdline.txt

@@ -1,4 +1,4 @@
-*cmdline.txt*   For Vim version 9.0.  Last change: 2023 May 20
+*cmdline.txt*   For Vim version 9.0.  Last change: 2023 Nov 15
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -362,6 +362,7 @@ terminals)
 		A positive number represents the absolute index of an entry
 		as it is given in the first column of a :history listing.
 		This number remains fixed even if other entries are deleted.
+		(see |E1510|)
 
 		A negative number means the relative position of an entry,
 		counted from the newest entry (which has index -1) backwards.

runtime/doc/tags

@@ -4514,6 +4514,7 @@ E1507	builtin.txt	/*E1507*
 E1508	editing.txt	/*E1508*
 E1509	editing.txt	/*E1509*
 E151	helphelp.txt	/*E151*
+E1510	change.txt	/*E1510*
 E152	helphelp.txt	/*E152*
 E153	helphelp.txt	/*E153*
 E154	helphelp.txt	/*E154*

src/ex_cmds.c

@@ -3993,6 +3993,13 @@ ex_substitute(exarg_T *eap)
 	    emsg(_(e_positive_count_required));
 	    return;
 	}
+	else if (i >= INT_MAX)
+	{
+	    char	buf[20];
+	    vim_snprintf(buf, sizeof(buf), "%ld", i);
+	    semsg(_(e_val_too_large), buf);
+	    return;
+	}
 	eap->line1 = eap->line2;
 	eap->line2 += i - 1;
 	if (eap->line2 > curbuf->b_ml.ml_line_count)

src/testdir/test_substitute.vim

@@ -206,6 +206,7 @@ func Test_substitute_count()
   call assert_equal(['foo foo', 'foo foo', 'foo foo', 'bar foo', 'bar foo'],
         \           getline(1, '$'))
 
+  call assert_fails('s/./b/2147483647', 'E1510:')
   bwipe!
 endfunc
 

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2108,
 /**/
     2107,
 /**/