- djm@cvs.openbsd.org 2010/08/12 21:49:44

[ssh.c]
     close any extra file descriptors inherited from parent at start and
     reopen stdin/stdout to /dev/null when forking for ControlPersist.

     prevents tools that fork and run a captive ssh for communication from
     failing to exit when the ssh completes while they wait for these fds to
     close. The inherited fds may persist arbitrarily long if a background
     mux master has been started by ControlPersist. cvs and scp were effected
     by this.

     "please commit" markus@
This commit is contained in:
Damien Miller 2010-08-17 01:59:31 +10:00
parent aa74f6754a
commit 00d9ae26db
2 changed files with 31 additions and 1 deletions

View File

@ -3,6 +3,19 @@
openbsd-compat/openbsd-compat.h openbsd-compat/strptime.c] Add strptime to
the compat library which helps on platforms like old IRIX. Based on work
by djm, tested by Tom Christensen.
- OpenBSD CVS Sync
- djm@cvs.openbsd.org 2010/08/12 21:49:44
[ssh.c]
close any extra file descriptors inherited from parent at start and
reopen stdin/stdout to /dev/null when forking for ControlPersist.
prevents tools that fork and run a captive ssh for communication from
failing to exit when the ssh completes while they wait for these fds to
close. The inherited fds may persist arbitrarily long if a background
mux master has been started by ControlPersist. cvs and scp were effected
by this.
"please commit" markus@
20100812
- (tim) [regress/login-timeout.sh regress/reconfigure.sh regress/reexec.sh

19
ssh.c
View File

@ -1,4 +1,4 @@
/* $OpenBSD: ssh.c,v 1.345 2010/08/04 05:42:47 djm Exp $ */
/* $OpenBSD: ssh.c,v 1.346 2010/08/12 21:49:44 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@ -237,6 +237,12 @@ main(int ac, char **av)
__progname = ssh_get_progname(av[0]);
init_rng();
/*
* Discard other fds that are hanging around. These can cause problem
* with backgrounded ssh processes started by ControlPersist.
*/
closefrom(STDERR_FILENO + 1);
/*
* Save the original real uid. It will be needed later (uid-swapping
* may clobber the real uid).
@ -898,6 +904,7 @@ static void
control_persist_detach(void)
{
pid_t pid;
int devnull;
debug("%s: backgrounding master process", __func__);
@ -924,6 +931,16 @@ control_persist_detach(void)
/* muxclient() doesn't return on success. */
fatal("Failed to connect to new control master");
}
if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) {
error("%s: open(\"/dev/null\"): %s", __func__,
strerror(errno));
} else {
if (dup2(devnull, STDIN_FILENO) == -1 ||
dup2(devnull, STDOUT_FILENO) == -1)
error("%s: dup2: %s", __func__, strerror(errno));
if (devnull > STDERR_FILENO)
close(devnull);
}
}
/* Do fork() after authentication. Used by "ssh -f" */