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| author | djm@openbsd.org <djm@openbsd.org> | 2021-05-19 01:24:05 +0000 |
|---|---|---|
| committer | Damien Miller <djm@mindrot.org> | 2021-05-19 11:52:14 +1000 |
| commit | 7be4ac813662f68e89f23c50de058a49aa32f7e4 (patch) | |
| tree | 7040d1e4601e2a0545e20614e96d8d818eccbf35 /ssh.c | |
| parent | c4902e1a653c67fea850ec99c7537f358904c0af (diff) | |
| download | openssh-git-7be4ac813662f68e89f23c50de058a49aa32f7e4.tar.gz | |
upstream: restore blocking status on stdio fds before close
ssh(1) needs to set file descriptors to non-blocking mode to operate
but it was not restoring the original state on exit. This could cause
problems with fds shared with other programs via the shell, e.g.
> $ cat > test.sh << _EOF
> #!/bin/sh
> {
> ssh -Fnone -oLogLevel=verbose ::1 hostname
> cat /usr/share/dict/words
> } | sleep 10
> _EOF
> $ ./test.sh
> Authenticated to ::1 ([::1]:22).
> Transferred: sent 2352, received 2928 bytes, in 0.1 seconds
> Bytes per second: sent 44338.9, received 55197.4
> cat: stdout: Resource temporarily unavailable
This restores the blocking status for fds 0,1,2 (stdio) before ssh(1)
abandons/closes them.
This was reported as bz3280 and GHPR246; ok dtucker@
OpenBSD-Commit-ID: 8cc67346f05aa85a598bddf2383fcfcc3aae61ce
Diffstat (limited to 'ssh.c')
| -rw-r--r-- | ssh.c | 17 |
1 files changed, 5 insertions, 12 deletions
@@ -1,4 +1,4 @@ -/* $OpenBSD: ssh.c,v 1.556 2021/05/17 11:43:16 djm Exp $ */ +/* $OpenBSD: ssh.c,v 1.557 2021/05/19 01:24:05 djm Exp $ */ /* * Author: Tatu Ylonen <ylo@cs.hut.fi> * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland @@ -1876,9 +1876,10 @@ ssh_init_stdio_forwarding(struct ssh *ssh) if ((in = dup(STDIN_FILENO)) == -1 || (out = dup(STDOUT_FILENO)) == -1) - fatal("channel_connect_stdio_fwd: dup() in/out failed"); + fatal_f("dup() in/out failed"); if ((c = channel_connect_stdio_fwd(ssh, options.stdio_forward_host, - options.stdio_forward_port, in, out)) == NULL) + options.stdio_forward_port, in, out, + CHANNEL_NONBLOCK_STDIO)) == NULL) fatal_f("channel_connect_stdio_fwd failed"); channel_register_cleanup(ssh, c->self, client_cleanup_stdio_fwd, 0); channel_register_open_confirm(ssh, c->self, ssh_stdio_confirm, NULL); @@ -2074,14 +2075,6 @@ ssh_session2_open(struct ssh *ssh) if (in == -1 || out == -1 || err == -1) fatal("dup() in/out/err failed"); - /* enable nonblocking unless tty */ - if (!isatty(in)) - set_nonblock(in); - if (!isatty(out)) - set_nonblock(out); - if (!isatty(err)) - set_nonblock(err); - window = CHAN_SES_WINDOW_DEFAULT; packetmax = CHAN_SES_PACKET_DEFAULT; if (tty_flag) { @@ -2091,7 +2084,7 @@ ssh_session2_open(struct ssh *ssh) c = channel_new(ssh, "session", SSH_CHANNEL_OPENING, in, out, err, window, packetmax, CHAN_EXTENDED_WRITE, - "client-session", /*nonblock*/0); + "client-session", CHANNEL_NONBLOCK_STDIO); debug3_f("channel_new: %d", c->self); |