ctags/CVE-2022-4515.patch

Based on
From e00c55d7a0204dc1d0ae316141323959e1e16162 Mon Sep 17 00:00:00 2001
From: Masatake YAMATO <yamato@redhat.com>
Date: Mon, 24 Oct 2016 23:52:23 +0900
Subject: [PATCH] main: quote output file name before passing it to system(3)
 function

Following command line doesn't work:

      $ ctags -o 'a b' ...

because a shell lauched from system(3) deals a whitespace between 'a'
and 'b' as a separator. The output file name is passed to system(3)
to run external sort command.

This commit adds code to put double and single quoets around the output
file name before passing it to system(3).

The issue is reported by Lorenz Hipp <lhipp@idealbonn.de> in a private mail.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
---
 Tmain/abnormal-output-file-names.d/input.c    |  1 +
 Tmain/abnormal-output-file-names.d/run.sh     | 39 ++++++++++
 .../stderr-expected.txt                       |  0
 .../stdout-expected.txt                       |  8 +++
 main/sort.c                                   | 72 ++++++++++++++-----
 5 files changed, 102 insertions(+), 18 deletions(-)
 create mode 100644 Tmain/abnormal-output-file-names.d/input.c
 create mode 100644 Tmain/abnormal-output-file-names.d/run.sh
 create mode 100644 Tmain/abnormal-output-file-names.d/stderr-expected.txt
 create mode 100644 Tmain/abnormal-output-file-names.d/stdout-expected.txt

Index: ctags-5.8/Tmain/abnormal-output-file-names.d/input.c
===================================================================
--- /dev/null
+++ ctags-5.8/Tmain/abnormal-output-file-names.d/input.c
@@ -0,0 +1 @@
+int x;
Index: ctags-5.8/Tmain/abnormal-output-file-names.d/run.sh
===================================================================
--- /dev/null
+++ ctags-5.8/Tmain/abnormal-output-file-names.d/run.sh
@@ -0,0 +1,39 @@
+# Copyright: 2016 Masatake YAMATO
+# License: GPL-2
+
+CTAGS=$1
+
+rm -f ./"'"
+rm -f ./'"'
+rm -f ./'$(ls)'
+rm -f ./'a b'
+
+${CTAGS} --options=NONE -o ./"'" --extra=-pF input.c
+${CTAGS} --options=NONE -o ./'"' --extra=-pF input.c
+${CTAGS} --options=NONE -o ./'$(ls)' --extra=-pF input.c
+${CTAGS} --options=NONE -o ./'a b' --extra=-pF input.c
+
+echo '#' SINGLE QUOTE
+if [ -e "'" ]; then
+	cat "'"
+fi
+
+echo '#' DOUBLE QUOTES
+if [ -e '"' ]; then
+	cat '"'
+fi
+
+echo '#' PROCESS SUBSTITUTION
+if [ -e '$(ls)' ]; then
+	cat '$(ls)'
+fi
+
+echo '#' SPACE
+if [ -e 'a b' ]; then
+	cat 'a b'
+fi
+
+rm -f ./"'"
+rm -f ./'"'
+rm -f ./'$(ls)'
+rm -f ./'a b'
Index: ctags-5.8/Tmain/abnormal-output-file-names.d/stdout-expected.txt
===================================================================
--- /dev/null
+++ ctags-5.8/Tmain/abnormal-output-file-names.d/stdout-expected.txt
@@ -0,0 +1,8 @@
+# SINGLE QUOTE
+x	input.c	/^int x;$/;"	v	typeref:typename:int
+# DOUBLE QUOTES
+x	input.c	/^int x;$/;"	v	typeref:typename:int
+# PROCESS SUBSTITUTION
+x	input.c	/^int x;$/;"	v	typeref:typename:int
+# SPACE
+x	input.c	/^int x;$/;"	v	typeref:typename:int
Index: ctags-5.8/sort.c
===================================================================
--- ctags-5.8.orig/sort.c
+++ ctags-5.8/sort.c
@@ -19,6 +19,7 @@
 #endif
 #include <string.h>
 #include <stdio.h>
+#include <unistd.h>
 
 #include "debug.h"
 #include "entry.h"
@@ -53,41 +54,83 @@ extern void catFile (const char *const n
 # define PE_CONST const
 #endif
 
+/*
+   Output file name should not be evaluated in system(3) function.
+   The name must be used as is. Quotations are required to block the
+   evaluation.
+
+   Normal single-quotes are used to quote a cstring:
+   a => 'a'
+   " => '"'
+
+   If a single-quote is included in the cstring, use double quotes for quoting it.
+   ' => ''"'"''
+*/
+static void appendCstringWithQuotes (vString *dest, const char* cstr)
+{
+       const char* o;
+
+       vStringPut (dest, '\'');
+       for (o = cstr; *o; o++)
+       {
+               if (*o == '\'')
+                       vStringCatS (dest, "'\"'\"'");
+               else
+                       vStringPut (dest, *o);
+       }
+       vStringPut (dest, '\'');
+}
+
 extern void externalSortTags (const boolean toStdout)
 {
-	const char *const sortNormalCommand = "sort -u -o";
-	const char *const sortFoldedCommand = "sort -u -f -o";
+	const char *const sortNormalCommand = "/usr/bin/sort -u";
+	const char *const sortFoldedCommand = "/usr/bin/sort -u -f";
 	const char *sortCommand =
 		Option.sorted == SO_FOLDSORTED ? sortFoldedCommand : sortNormalCommand;
+# ifndef HAVE_SETENV
 	PE_CONST char *const sortOrder1 = "LC_COLLATE=C";
 	PE_CONST char *const sortOrder2 = "LC_ALL=C";
-	const size_t length = 4 + strlen (sortOrder1) + strlen (sortOrder2) +
-			strlen (sortCommand) + (2 * strlen (tagFileName ()));
-	char *const cmd = (char *) malloc (length + 1);
+# endif
+	vString *cmd = vStringNew ();
 	int ret = -1;
 
 	if (cmd != NULL)
 	{
 		/*  Ensure ASCII value sort order.
 		 */
-#ifdef HAVE_SETENV
+#if defined(HAVE_SETENV) || defined(HAVE_PUTENV)
+# if HAVE_SETENV
 		setenv ("LC_COLLATE", "C", 1);
 		setenv ("LC_ALL", "C", 1);
-		sprintf (cmd, "%s %s %s", sortCommand, tagFileName (), tagFileName ());
-#else
-# ifdef HAVE_PUTENV
+# else
 		putenv (sortOrder1);
 		putenv (sortOrder2);
-		sprintf (cmd, "%s %s %s", sortCommand, tagFileName (), tagFileName ());
-# else
-		sprintf (cmd, "%s %s %s %s %s", sortOrder1, sortOrder2, sortCommand,
-				tagFileName (), tagFileName ());
 # endif
+		vStringCatS (cmd, sortCommand);
+//		if (! toStdout)
+		{
+			vStringCatS (cmd, " -o ");
+			appendCstringWithQuotes (cmd, tagFileName ());
+			vStringPut (cmd, ' ');
+			appendCstringWithQuotes (cmd, tagFileName ());
+		}
+#else
+		vStringCatS (cmd, sortOrder1);
+		vStringPut (cmd, ' ');
+		vStringCatS (cmd, sortOrder2);
+		vStringPut (cmd, ' ');
+		vStringCatS (cmd, sortCommand);
+//		if (! toStdout)
+		{
+			vStringCats (cmd, " -o ");
+			appendCstringWithQuotes (cmd, tagFileName ());
+			vStringPut (cmd, ' ');
+			appendCstringWithQuotes (cmd, tagFileName ());
+		}
 #endif
-		verbose ("system (\"%s\")\n", cmd);
-		ret = system (cmd);
-		free (cmd);
-
+		verbose ("system (\"%s\")\n", vStringValue(cmd));
+		ret = system (vStringValue(cmd));
+		vStringDelete (cmd);
 	}
 	if (ret != 0)
 		error (FATAL | PERROR, "cannot sort tag file");