Re: [sysvinit-devel] [PATCH 2/5] init.c: add return tests for dup() in spawn()

[Michał Kulling]

Hi Petter!

Could you apply patch from attachment?
I added four new variables at the top of spawn() for TTY controlling and 
duplicated /dev/null.

Coverity mark my changes as resource leak because I'm not assign 
descriptor returned from dup().

Patch for rev 159.

Best regards, Mike.


[Michał Kulling]
Currently in spawn() function is using dup() without return code
validation, i added simple check with additional output to stderr.
Thank you.  Applied.



--
Michal Kulling

--- init.c-orig	2014-02-11 20:31:37.688063205 +0100
+++ init.c	2014-02-11 20:38:45.580073375 +0100
@@ -978,6 +978,8 @@
   char *args[16];		/* Argv array */
   char buf[136];		/* Line buffer */
   int f, st;			/* Scratch variables */
+  int fdtty1, fdtty2;		/* Handlers for TTY controlling dup()*/
+  int fdnull1, fdnull2;		/* Handlers for /dev/null dup() */
   char *ptr;			/* Ditto */
   time_t t;			/* System time */
   int oldAlarm;			/* Previous alarm value */
@@ -1111,12 +1113,15 @@
 			if ((ftty = console_open(O_RDWR|O_NOCTTY)) >= 0) {
 				/* Take over controlling tty by force */
 				(void)ioctl(ftty, TIOCSCTTY, 1);
+				
+				fdtty1 = dup(ftty);
+				fdtty2 = dup(ftty);
 
-				if(dup(ftty) < 0){
+				if(fdtty1 == -1){
 				        initlog(L_VB, "cannot duplicate console fd");
 				}
 				
-				if(dup(ftty) < 0){
+				if(fdtty2 == -1){
 				        initlog(L_VB, "cannot duplicate console fd");
 				}
 
@@ -1189,11 +1194,14 @@
 				fd = open("/dev/null", O_RDWR);
 			}
 
-			if(dup(fd) < 0) {
+			fdnull1 = dup(fd);
+			fdnull2 = dup(fd);
+
+			if(fdnull1 == -1) {
 				initlog(L_VB, "cannot duplicate /dev/null fd");
 			}
 			
-			if(dup(fd) < 0) {
+			if(fdnull2 < 0) {
 				initlog(L_VB, "cannot duplicate /dev/null fd");
 			}