Call setsid() in the child after sshd accepts the connection and forks.

This is needed for privsep which calls setlogin() when it changes uids.
Without this, there is a race where the login name of an existing connection,
as returned by getlogin(), may be changed to the privsep user (sshd).
markus@ OK

1 files changed, 9 insertions, 1 deletions

diff --git a/usr.bin/ssh/sshd.c b/usr.bin/ssh/sshd.c
index ec01386a148..7e92e0ab744 100644
--- a/usr.bin/ssh/sshd.c
+++ b/usr.bin/ssh/sshd.c
@@ -42,7 +42,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: sshd.c,v 1.240 2002/04/23 22:16:29 djm Exp $");
+RCSID("$OpenBSD: sshd.c,v 1.241 2002/05/13 15:53:19 millert Exp $");
 
 #include <openssl/dh.h>
 #include <openssl/bn.h>
@@ -1292,6 +1292,14 @@ main(int ac, char **av)
 	/* This is the child processing a new connection. */
 
 	/*
+	 * Create a new session and process group since the 4.4BSD
+	 * setlogin() affects the entire process group.  We don't
+	 * want the child to be able to affect the parent.
+	 */
+	if (setsid() < 0)
+		error("setsid: %.100s", strerror(errno));
+
+	/*
 	 * Disable the key regeneration alarm.  We will not regenerate the
 	 * key since we are no longer in a position to give it to anyone. We
 	 * will not restart on SIGHUP since it no longer makes sense.