Close security holes and restore suid bit

Restore writting cat's functionality

gnu/usr.bin/man/man/Makefile

@@ -1,5 +1,7 @@
 PROG=	man
 SRCS=	man.c manpath.c glob.c
+BINOWN= man
+BINMODE=4555
 
 .if exists(${.CURDIR}/../lib/obj)
 LDADD=  -L${.CURDIR}/../lib/obj -lman

gnu/usr.bin/man/man/man.c

@@ -19,6 +19,7 @@
 #include <sys/types.h>
 #include <stdio.h>
 #include <ctype.h>
+#include <errno.h>
 #include <string.h>
 #include <sys/file.h>
 #include <signal.h>
@@ -131,6 +132,7 @@ main (argc, argv)
 
   prognam = mkprogname (argv[0]);
 
+  unsetenv("IFS");
   man_getopt (argc, argv);
 
   if (optind == argc)
@@ -981,7 +983,7 @@ make_roff_command (file)
     fprintf (stderr, "using default preprocessor sequence\n");
 
   if ((cp = get_expander(file)) == NULL)
-    cp = "cat";
+    cp = "/bin/cat";
   sprintf(buf, "%s %s | ", cp, file);
 #ifdef HAS_TROFF
   if (troff)
@@ -1020,6 +1022,33 @@ make_roff_command (file)
   return buf;
 }
 
+sig_t ohup, oint, oquit, oterm;
+static char temp[FILENAME_MAX];
+
+void cleantmp()
+{
+	unlink(temp);
+	exit(1);
+}
+
+void
+set_sigs()
+{
+  ohup = signal(SIGHUP, cleantmp);
+  oint = signal(SIGINT, cleantmp);
+  oquit = signal(SIGQUIT, cleantmp);
+  oterm = signal(SIGTERM, cleantmp);
+}
+
+void
+restore_sigs()
+{
+  signal(SIGHUP, ohup);
+  signal(SIGINT, oint);
+  signal(SIGQUIT, oquit);
+  signal(SIGTERM, oterm);
+}
+
 /*
  * Try to format the man page and create a new formatted file.  Return
  * 1 for success and 0 for failure.
@@ -1030,73 +1059,121 @@ make_cat_file (path, man_file, cat_file)
      register char *man_file;
      register char *cat_file;
 {
-  int status;
-  int mode;
-  FILE *fp;
+  int s, f;
+  FILE *fp, *pp;
   char *roff_command;
   char command[FILENAME_MAX];
-  char temp[FILENAME_MAX];
 
-  sprintf(temp, "%s.tmp", cat_file);
-  if ((fp = fopen (temp, "w")) != NULL)
+  roff_command = make_roff_command (man_file);
+  if (roff_command == NULL)
+      return 0;
+
+  sprintf(temp, "%s.tmpXXXXXX", cat_file);
+  if ((f = mkstemp(temp)) >= 0 && (fp = fdopen(f, "w")) != NULL)
     {
-      fclose (fp);
-      unlink (temp);
+      set_sigs();
 
-      roff_command = make_roff_command (man_file);
-      if (roff_command == NULL)
+      if (fchmod (f, CATMODE) < 0) {
+	perror("fchmod");
+	unlink(temp);
+	restore_sigs();
+	fclose(fp);
 	return 0;
-      else
+      } else if (debug)
+	fprintf (stderr, "mode of %s is now %o\n", temp, CATMODE);
+
 #ifdef DO_COMPRESS
-	sprintf (command, "(cd %s ; %s | %s > %s)", path,
-		 roff_command, COMPRESSOR, temp);
+      sprintf (command, "(cd %s ; %s | %s)", path,
+		roff_command, COMPRESSOR);
 #else
-        sprintf (command, "(cd %s ; %s > %s)", path,
-		 roff_command, temp);
+      sprintf (command, "(cd %s ; %s)", path,
+		roff_command);
 #endif
-      /*
-       * Don't let the user interrupt the system () call and screw up
-       * the formatted man page if we're not done yet.
-       */
       fprintf (stderr, "Formatting page, please wait...");
       fflush(stderr);
 
-      status = do_system_command (command);
-
-      if (status <= 0) {
-	fprintf(stderr, "Failed.\n");
-	unlink(temp);
-	return(0);
-      }
+      if (debug)
+	fprintf (stderr, "\ntrying command: %s\n", command);
       else {
-        if (rename(temp, cat_file) == -1) {
-		/* FS might be sticky */
-		sprintf(command, "cp %s %s", temp, cat_file);
-		if (system(command))
-			fprintf(stderr,
-				"\nHmm!  Can't seem to rename %s to %s, check permissions on man dir!\n",
-				temp, cat_file);
-		unlink(temp);
-		return 0;
+
+	if ((pp = popen(command, "r")) == NULL) {
+	  s = errno;
+	  fprintf(stderr, "Failed.\n");
+	  errno = s;
+	  perror("popen");
+	  unlink(temp);
+	  restore_sigs();
+	  fclose(fp);
+	  return 0;
+	}
+
+	while ((s = getc(pp)) != EOF)
+	  putc(s, fp);
+
+	if ((s = pclose(pp)) == -1) {
+	  s = errno;
+	  fprintf(stderr, "Failed.\n");
+	  errno = s;
+	  perror("pclose");
+	  unlink(temp);
+	  restore_sigs();
+	  fclose(fp);
+	  return 0;
+	}
+
+	if (s != 0) {
+	  fprintf(stderr, "Failed.\n");
+	  gripe_system_command(s);
+	  unlink(temp);
+	  restore_sigs();
+	  fclose(fp);
+	  return 0;
 	}
       }
+
+      if (rename(temp, cat_file) == -1) {
+	s = errno;
+	fprintf(stderr,
+		 "\nHmm!  Can't seem to rename %s to %s, check permissions on man dir!\n",
+		 temp, cat_file);
+	errno = s;
+	perror("rename");
+	unlink(temp);
+	restore_sigs();
+	fclose(fp);
+	return 0;
+      }
+      restore_sigs();
+
+      if (fclose(fp)) {
+	s = errno;
+	unlink(cat_file);
+	fprintf(stderr, "Failed.\n");
+	errno = s;
+	perror("fclose");
+	return 0;
+      }
+
       fprintf(stderr, "Done.\n");
-      if (status == 1)
-	{
-	  mode = CATMODE;
-	  chmod (cat_file, mode);
-
-	  if (debug)
-	    fprintf (stderr, "mode of %s is now %o\n", cat_file, mode);
-	}
-
 
       return 1;
     }
   else
     {
-      if (debug)
-	fprintf (stderr, "Couldn't open %s for writing.\n", cat_file);
+      if (f >= 0) {
+	s = errno;
+	unlink(temp);
+	errno = s;
+      }
+      if (debug) {
+	s = errno;
+	fprintf (stderr, "Couldn't open %s for writing.\n", temp);
+	errno = s;
+      }
+      if (f >= 0) {
+	perror("fdopen");
+	close(f);
+      }
 
       return 0;
     }