From: Todd C. Miller <Todd.Miller@courtesan.com>
Date: Mon, 26 Jul 2010 17:03:44 +0000 (-0400)
Subject: Handle ENXIO from read/write which can occur when reading/writing
X-Git-Tag: SUDO_1_7_4~24
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=13cff351118e8d64bed317d4a88d2a54adbe8f34;p=sudo

Handle ENXIO from read/write which can occur when reading/writing
a pty that has gone away.  Fixes bugzilla 422

--HG--
branch : 1.7
---

diff --git a/exec_pty.c b/exec_pty.c
index af034d566..ca607472d 100644
--- a/exec_pty.c
+++ b/exec_pty.c
@@ -287,17 +287,25 @@ perform_io(fdsr, fdsw, cstat)
 		n = read(iob->rfd, iob->buf + iob->len,
 		    sizeof(iob->buf) - iob->len);
 	    } while (n == -1 && errno == EINTR);
-	    if (n == -1) {
-		if (errno != EAGAIN)
+	    switch (n) {
+		case -1:
+		    if (errno == EAGAIN)
+			break;
+		    if (errno != ENXIO && errno != EBADF) {
+			errors++;
+			break;
+		    }
+		    /* FALLTHROUGH */
+		case 0:
+		    /* got EOF or pty has gone away */
+		    safe_close(iob->rfd);
+		    iob->rfd = -1;
+		    break;
+		default:
+		    if (!iob->action(iob->buf + iob->len, n))
+			terminate_child(child, TRUE);
+		    iob->len += n;
 		    break;
-	    } else if (n == 0) {
-		/* got EOF */
-		safe_close(iob->rfd);
-		iob->rfd = -1;
-	    } else {
-		if (!iob->action(iob->buf + iob->len, n))
-		    terminate_child(child, TRUE);
-		iob->len += n;
 	    }
 	}
 	if (iob->wfd != -1 && FD_ISSET(iob->wfd, fdsw)) {
@@ -306,8 +314,8 @@ perform_io(fdsr, fdsw, cstat)
 		    iob->len - iob->off);
 	    } while (n == -1 && errno == EINTR);
 	    if (n == -1) {
-		if (errno == EPIPE) {
-		    /* other end of pipe closed */
+		if (errno == EPIPE || errno == ENXIO || errno == EBADF) {
+		    /* other end of pipe closed or pty revoked */
 		    if (iob->rfd != -1) {
 			safe_close(iob->rfd);
 			iob->rfd = -1;