replace remaining setuid() calls with permanently_set_uid() and

check seteuid() return values; report Marcus Meissner; ok dtucker djm

5 files changed, 24 insertions, 19 deletions

diff --git a/usr.bin/ssh/readpass.c b/usr.bin/ssh/readpass.c
index 05264d893c9..02cf8a94688 100644
--- a/usr.bin/ssh/readpass.c
+++ b/usr.bin/ssh/readpass.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: readpass.c,v 1.37 2006/03/25 13:17:02 djm Exp $ */
+/* $OpenBSD: readpass.c,v 1.38 2006/06/06 10:20:20 markus Exp $ */
 /*
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
  *
@@ -36,6 +36,7 @@
 #include "pathnames.h"
 #include "log.h"
 #include "ssh.h"
+#include "uidswap.h"
 
 static char *
 ssh_askpass(char *askpass, const char *msg)
@@ -59,8 +60,7 @@ ssh_askpass(char *askpass, const char *msg)
 		return NULL;
 	}
 	if (pid == 0) {
-		seteuid(getuid());
-		setuid(getuid());
+		permanently_set_uid(getpwuid(getuid()));
 		close(p[0]);
 		if (dup2(p[1], STDOUT_FILENO) < 0)
 			fatal("ssh_askpass: dup2: %s", strerror(errno));
diff --git a/usr.bin/ssh/sshconnect.c b/usr.bin/ssh/sshconnect.c
index 2a7d5417015..bcb5e94457d 100644
--- a/usr.bin/ssh/sshconnect.c
+++ b/usr.bin/ssh/sshconnect.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshconnect.c,v 1.182 2006/05/17 12:43:34 markus Exp $ */
+/* $OpenBSD: sshconnect.c,v 1.183 2006/06/06 10:20:20 markus Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -91,8 +91,7 @@ ssh_proxy_connect(const char *host, u_short port, const char *proxy_command)
 		char *argv[10];
 
 		/* Child.  Permanently give up superuser privileges. */
-		seteuid(original_real_uid);
-		setuid(original_real_uid);
+		permanently_set_uid(getpwuid(original_real_uid));
 
 		/* Redirect stdin and stdout. */
 		close(pin[1]);
diff --git a/usr.bin/ssh/sshconnect.h b/usr.bin/ssh/sshconnect.h
index 3786ba56ee0..692d2756753 100644
--- a/usr.bin/ssh/sshconnect.h
+++ b/usr.bin/ssh/sshconnect.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshconnect.h,v 1.19 2006/03/25 22:22:43 djm Exp $ */
+/* $OpenBSD: sshconnect.h,v 1.20 2006/06/06 10:20:20 markus Exp $ */
 
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
@@ -54,16 +54,20 @@ int	 ssh_local_cmd(const char *);
 /*
  * Macros to raise/lower permissions.
  */
-#define PRIV_START do {				\
-	int save_errno = errno;			\
-	(void)seteuid(original_effective_uid);	\
-	errno = save_errno;			\
+#define PRIV_START do {					\
+	int save_errno = errno;				\
+	if (seteuid(original_effective_uid) != 0)	\
+		fatal("PRIV_START: seteuid: %s",	\
+		    strerror(errno));			\
+	errno = save_errno;				\
 } while (0)
 
-#define PRIV_END do {				\
-	int save_errno = errno;			\
-	(void)seteuid(original_real_uid);	\
-	errno = save_errno;			\
+#define PRIV_END do {					\
+	int save_errno = errno;				\
+	if (seteuid(original_real_uid) != 0)		\
+		fatal("PRIV_END: seteuid: %s",		\
+		    strerror(errno));			\
+	errno = save_errno;				\
 } while (0)
 
 #endif
diff --git a/usr.bin/ssh/sshconnect2.c b/usr.bin/ssh/sshconnect2.c
index fef0d52b177..16ab3d0f052 100644
--- a/usr.bin/ssh/sshconnect2.c
+++ b/usr.bin/ssh/sshconnect2.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshconnect2.c,v 1.153 2006/05/08 10:49:48 djm Exp $ */
+/* $OpenBSD: sshconnect2.c,v 1.154 2006/06/06 10:20:20 markus Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
@@ -52,6 +52,7 @@
 #include "canohost.h"
 #include "msg.h"
 #include "pathnames.h"
+#include "uidswap.h"
 
 #ifdef GSSAPI
 #include "ssh-gss.h"
@@ -1251,8 +1252,7 @@ ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
 		return -1;
 	}
 	if (pid == 0) {
-		seteuid(getuid());
-		setuid(getuid());
+		permanently_set_uid(getpwuid(getuid()));
 		close(from[0]);
 		if (dup2(from[1], STDOUT_FILENO) < 0)
 			fatal("ssh_keysign: dup2: %s", strerror(errno));
diff --git a/usr.bin/ssh/uidswap.c b/usr.bin/ssh/uidswap.c
index 5891b71d4bd..75a1d7cb467 100644
--- a/usr.bin/ssh/uidswap.c
+++ b/usr.bin/ssh/uidswap.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: uidswap.c,v 1.27 2006/04/22 04:06:51 djm Exp $ */
+/* $OpenBSD: uidswap.c,v 1.28 2006/06/06 10:20:20 markus Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -111,6 +111,8 @@ restore_uid(void)
 void
 permanently_set_uid(struct passwd *pw)
 {
+	if (pw == NULL)
+		fatal("permanently_set_uid: no user given");
 	if (temporarily_use_uid_effective)
 		fatal("permanently_set_uid: temporarily_use_uid effective");
 	debug("permanently_set_uid: %u/%u", (u_int)pw->pw_uid,