gww@beatnix.UUCP (Gary Winiger) (03/13/88)
Subject: touch with no files dereferences a null pointer +Fix
Index: usr.bin/touch.c 4.3BSD +Fix
Description:
If touch is called with no files, it will dereference a null pointer.
On systems which don't permit null pointer dereferences, this will
cause a core dump.
Repeat-By:
touch
On a system which doesn't permit null pointer dereferences.
Fix:
Test to see if a parameter was passed.
The attached code solves this problem at Elxsi.
Gary..
{ucbvax!sun,uunet,lll-lcc!lll-tis,amdahl!altos86,bridge2}!elxsi!gww
--------- cut --------- snip --------- :.,$w diff -------------
*** /tmp/,RCSt1001870 Tue Sep 8 17:41:04 1987
--- touch.c Tue Sep 8 17:15:19 1987
***************
*** 1,11 ****
/*
* $Log: touch.c,v $
* Revision 1.1 86/12/30 10:24:34 gww
* Initial revision
*
*/
#ifndef lint
! static char *ERcsId = "$Header: touch.c,v 1.1 86/12/30 10:24:34 gww Exp $ ENIX BSD";
static char sccsid[] = "@(#)touch.c 4.3 (Berkeley) 8/11/83";
#endif
--- 1,15 ----
/*
* $Log: touch.c,v $
+ * Revision 1.2 87/09/08 17:14:30 gww
+ * If no file(s) is (are) specified, give a usage message and don't dereference
+ * a null pointer.
+ *
* Revision 1.1 86/12/30 10:24:34 gww
* Initial revision
*
*/
#ifndef lint
! static char *ERcsId = "$Header: touch.c,v 1.2 87/09/08 17:14:30 gww Exp $ ENIX BSD";
static char sccsid[] = "@(#)touch.c 4.3 (Berkeley) 8/11/83";
#endif
***************
*** 33,39 ****
dontcreate = 0;
force = 0;
! for (argv++; **argv == '-'; argv++) {
for (argp = &(*argv)[1]; *argp; argp++) {
switch (*argp) {
case 'c':
--- 37,43 ----
dontcreate = 0;
force = 0;
! for (argc--, argv++; argc >= 1 && **argv == '-'; argc--, argv++) {
for (argp = &(*argv)[1]; *argp; argp++) {
switch (*argp) {
case 'c':
***************
*** 48,53 ****
--- 52,61 ----
exit(1);
}
}
+ }
+ if (argc < 1) {
+ fprintf(stderr, "usage: touch [-c] [-f] file ...\n");
+ exit(1);
}
for (/*void*/; *argv; argv++) {
touch(*argv);