From: Dave Hart <hart@ntp.org>
Date: Tue, 7 Dec 2010 08:42:46 +0000 (+0000)
Subject: [Bug 1732] ntpd ties up CPU on disconnected USB device.
X-Git-Tag: NTP_4_2_7P91~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8ea3cbafff8d9ef2b999c59fff49c1418ab5e111;p=thirdparty%2Fntp.git

[Bug 1732] ntpd ties up CPU on disconnected USB device.

bk: 4cfdf386UdHCYZjSIh-qifB9n8eYEA
---

diff --git a/ChangeLog b/ChangeLog
index c97de3e98..d12b08dd5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,4 @@
+* [Bug 1732] ntpd ties up CPU on disconnected USB device.
 (4.2.7p90) 2010/12/06 Released by Harlan Stenn <stenn@ntp.org>
 * [Bug 1738] Windows ntpd has wrong net adapter name.
 * [Bug 1740] ntpdc -c reslist packet count wrongly treated as signed.
diff --git a/ntpd/ntp_io.c b/ntpd/ntp_io.c
index 4b7cad12c..00951e0bf 100644
--- a/ntpd/ntp_io.c
+++ b/ntpd/ntp_io.c
@@ -3492,6 +3492,7 @@ input_handler(
 	 */
 	if (n < 0) {
 		int err = errno;
+		int j, b, prior;
 		/*
 		 * extended FAU debugging output
 		 */
@@ -3500,15 +3501,21 @@ input_handler(
 				"select(%d, %s, 0L, 0L, &0.0) error: %m",
 				maxactivefd + 1,
 				fdbits(maxactivefd, &activefds));
-		if (err == EBADF) {
-			int j, b;
-			fds = activefds;
-			for (j = 0; j <= maxactivefd; j++)
-				if ((FD_ISSET(j, &fds)
-				    && (read(j, &b, 0) == -1)))
-					msyslog(LOG_ERR,
-						"Bad file descriptor %d",
-						j);
+		if (err != EBADF)
+			return;
+		for (j = 0, prior = 0; j <= maxactivefd; j++) {
+			if (FD_ISSET(j, &activefds)) {
+				if (-1 != read(j, &b, 0)) {
+					prior = j;
+					continue;
+				}
+				msyslog(LOG_ERR,
+					"Removing bad file descriptor %d from select set",
+					j);
+				FD_CLR(j, &activefds);
+				if (j == maxactivefd)
+					maxactivefd = prior;
+			}
 		}
 		return;
 	}