From: tedu <tedu@openbsd.org>
Date: Mon, 3 Apr 2017 17:23:39 +0000 (+0000)
Subject: check return from pread, don't divide -1 for count
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=db006180e56b790d51443987f96346d99e672470;p=openbsd

check return from pread, don't divide -1 for count
---

diff --git a/libexec/comsat/comsat.c b/libexec/comsat/comsat.c
index ef9a0b4d18e..df7283b29ac 100644
--- a/libexec/comsat/comsat.c
+++ b/libexec/comsat/comsat.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: comsat.c,v 1.47 2017/04/03 17:07:58 deraadt Exp $	*/
+/*	$OpenBSD: comsat.c,v 1.48 2017/04/03 17:23:39 tedu Exp $	*/
 
 /*
  * Copyright (c) 1980, 1993
@@ -170,6 +170,7 @@ doreadutmp(void)
 	static u_int utmpsize;		/* last malloced size for utmp */
 	static time_t utmpmtime;	/* last modification time for utmp */
 	struct stat statbf;
+	int n;
 
 	if (time(NULL) - lastmsgtime >= MAXIDLE)
 		exit(0);
@@ -195,7 +196,10 @@ doreadutmp(void)
 			utmp = u;
 			utmpsize = nutmpsize;
 		}
-		nutmp = pread(uf, utmp, statbf.st_size, 0)/sizeof(struct utmp);
+		n = pread(uf, utmp, statbf.st_size, 0);
+		if (n == -1)
+			n = 0;
+		nutmp = n / sizeof(struct utmp);
 		dsyslog(LOG_DEBUG, "read %d utmp entries", nutmp);
 	}
 	(void)alarm(15);