upstream: when restoring non-blocking mode to stdio fds, restore

exactly the flags that ssh started with and don't just clobber them with
zero, as this could also remove the append flag from the set;

bz3523; ok dtucker@

OpenBSD-Commit-ID: 1336b03e881db7564a4b66014eb24c5230e9a0c0

diff --git a/channels.c b/channels.c
index 981746ebd6ec798c132e87bcfc48f6212c7f996e..0d26358cc65e4ac4d2bf55970f2deec5ed1a2f98 100644 (file)
--- a/channels.c
+++ b/channels.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: channels.c,v 1.426 2023/01/06 02:47:18 djm Exp $ */
+/* $OpenBSD: channels.c,v 1.427 2023/01/18 02:00:10 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -417,16 +417,19 @@ channel_register_fds(struct ssh *ssh, Channel *c, int rfd, int wfd, int efd,
                 */
                if (rfd != -1 && !isatty(rfd) &&
                    (val = fcntl(rfd, F_GETFL)) != -1 && !(val & O_NONBLOCK)) {
+                       c->restore_flags[0] = val;
                        c->restore_block |= CHANNEL_RESTORE_RFD;
                        set_nonblock(rfd);
                }
                if (wfd != -1 && !isatty(wfd) &&
                    (val = fcntl(wfd, F_GETFL)) != -1 && !(val & O_NONBLOCK)) {
+                       c->restore_flags[1] = val;
                        c->restore_block |= CHANNEL_RESTORE_WFD;
                        set_nonblock(wfd);
                }
                if (efd != -1 && !isatty(efd) &&
                    (val = fcntl(efd, F_GETFL)) != -1 && !(val & O_NONBLOCK)) {
+                       c->restore_flags[2] = val;
                        c->restore_block |= CHANNEL_RESTORE_EFD;
                        set_nonblock(efd);
                }
@@ -510,10 +513,16 @@ channel_close_fd(struct ssh *ssh, Channel *c, int *fdp)
        if (fd == -1)
                return 0;
 
-       if ((*fdp == c->rfd && (c->restore_block & CHANNEL_RESTORE_RFD) != 0) ||
-          (*fdp == c->wfd && (c->restore_block & CHANNEL_RESTORE_WFD) != 0) ||
-          (*fdp == c->efd && (c->restore_block & CHANNEL_RESTORE_EFD) != 0))
-               (void)fcntl(*fdp, F_SETFL, 0);  /* restore blocking */
+       /* restore blocking */
+       if (*fdp == c->rfd &&
+           (c->restore_block & CHANNEL_RESTORE_RFD) != 0)
+               (void)fcntl(*fdp, F_SETFL, c->restore_flags[0]);
+       else if (*fdp == c->wfd &&
+           (c->restore_block & CHANNEL_RESTORE_WFD) != 0)
+               (void)fcntl(*fdp, F_SETFL, c->restore_flags[1]);
+       else if (*fdp == c->efd &&
+           (c->restore_block & CHANNEL_RESTORE_EFD) != 0)
+               (void)fcntl(*fdp, F_SETFL, c->restore_flags[2]);
 
        if (*fdp == c->rfd) {
                c->io_want &= ~SSH_CHAN_IO_RFD;

diff --git a/channels.h b/channels.h
index c80b55d0c7c4344905db2bc7dc25816061372b50..101843a06d15998b06efbdf32f586ea967f43c86 100644 (file)
--- a/channels.h
+++ b/channels.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: channels.h,v 1.147 2023/01/06 02:47:18 djm Exp $ */
+/* $OpenBSD: channels.h,v 1.148 2023/01/18 02:00:10 djm Exp $ */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -153,6 +153,7 @@ struct Channel {
                                 * this way post-IO handlers are not
                                 * accidentally called if a FD gets reused */
        int     restore_block;  /* fd mask to restore blocking status */
+       int     restore_flags[3];/* flags to restore */
        struct sshbuf *input;   /* data read from socket, to be sent over
                                 * encrypted connection */
        struct sshbuf *output;  /* data received over encrypted connection for