- (djm) [openbsd-compat/sigact.c] Avoid NULL derefs in ancient sigaction

replacement code; patch from ighighi AT gmail.com in bz#1240;
   ok dtucker

ChangeLog

@@ -1,3 +1,8 @@
+20080614
+ - (djm) [openbsd-compat/sigact.c] Avoid NULL derefs in ancient sigaction
+   replacement code; patch from ighighi AT gmail.com in bz#1240;
+   ok dtucker
+
 20080613
  - (dtucker) OpenBSD CVS Sync
    - deraadt@cvs.openbsd.org 2008/06/13 09:44:36
@@ -4364,4 +4369,4 @@
    OpenServer 6 and add osr5bigcrypt support so when someone migrates
    passwords between UnixWare and OpenServer they will still work. OK dtucker@
 
-$Id: ChangeLog,v 1.5010 2008/06/13 23:14:46 dtucker Exp $
+$Id: ChangeLog,v 1.5011 2008/06/15 00:55:34 djm Exp $

openbsd-compat/sigact.c

@@ -36,6 +36,7 @@
 /* OPENBSD ORIGINAL: lib/libcurses/base/sigaction.c */
 
 #include "includes.h"
+#include <errno.h>
 #include <signal.h>
 #include "sigact.h"
 
@@ -47,12 +48,17 @@
 int
 sigaction(int sig, struct sigaction *sigact, struct sigaction *osigact)
 {
-	return sigvec(sig, &(sigact->sv), &(osigact->sv));
+	return sigvec(sig, sigact ? &sigact->sv : NULL,
+	    osigact ? &osigact->sv : NULL);
 }
 
 int
 sigemptyset (sigset_t *mask)
 {
+	if (!mask) {
+		errno = EINVAL;
+		return -1;
+	}
 	*mask = 0;
 	return 0;
 }
@@ -62,7 +68,13 @@ sigprocmask (int mode, sigset_t * mask, sigset_t * omask)
 {
 	sigset_t current = sigsetmask(0);
 
-	if (omask) *omask = current;
+	if (!mask) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	if (omask)
+		*omask = current;
 
 	if (mode == SIG_BLOCK)
 		current |= *mask;
@@ -78,12 +90,20 @@ sigprocmask (int mode, sigset_t * mask, sigset_t * omask)
 int
 sigsuspend (sigset_t *mask)
 {
+	if (!mask) {
+		errno = EINVAL;
+		return -1;
+	}
 	return sigpause(*mask);
 }
 
 int
 sigdelset (sigset_t *mask, int sig)
 {
+	if (!mask) {
+		errno = EINVAL;
+		return -1;
+	}
 	*mask &= ~sigmask(sig);
 	return 0;
 }
@@ -91,6 +111,10 @@ sigdelset (sigset_t * mask, int sig)
 int
 sigaddset (sigset_t *mask, int sig)
 {
+	if (!mask) {
+		errno = EINVAL;
+		return -1;
+	}
 	*mask |= sigmask(sig);
 	return 0;
 }
@@ -98,6 +122,10 @@ sigaddset (sigset_t * mask, int sig)
 int
 sigismember (sigset_t *mask, int sig)
 {
+	if (!mask) {
+		errno = EINVAL;
+		return -1;
+	}
 	return (*mask & sigmask(sig)) != 0;
 }