>From 00f63e1afc9d07e9793574304ef34a5bb54629b7 Mon Sep 17 00:00:00 2001
From: "Yuriy M. Kaminskiy" <yumkam@gmail.com>
Date: Wed, 2 Jan 2013 01:56:07 +0400
Subject: [PATCH 5/7] ping, ping6, arping, clockdiff: Fix CAP_SETUID <->
 setuid() interaction

setuid() only drops saved uid if process have CAP_SETUID.
Drop capabilities only after setuid().
---
 arping.c      |   30 +++++++++++++++---------------
 clockdiff.c   |    8 +++++---
 ping_common.c |   30 +++++++++++++++---------------
 3 files changed, 35 insertions(+), 33 deletions(-)

diff --git a/arping.c b/arping.c
index 0033f33..3c02abf 100644
--- a/arping.c
+++ b/arping.c
@@ -161,6 +161,21 @@ void limit_capabilities(void)
 #ifdef CAPABILITIES
 	cap_t cap_p;
 
+	if (prctl(PR_SET_KEEPCAPS, 1) < 0) {
+		perror("arping: prctl");
+		exit(-1);
+	}
+
+	if (setuid(getuid()) < 0) {
+		perror("arping: setuid");
+		exit(-1);
+	}
+
+	if (prctl(PR_SET_KEEPCAPS, 0) < 0) {
+		perror("arping: prctl");
+		exit(-1);
+	}
+
 	cap_p = cap_get_proc();
 	if (!cap_p) {
 		perror("arping: cap_get_proc");
@@ -184,21 +199,6 @@ void limit_capabilities(void)
 		}
 	}
 
-	if (prctl(PR_SET_KEEPCAPS, 1) < 0) {
-		perror("arping: prctl");
-		exit(-1);
-	}
-
-	if (setuid(getuid()) < 0) {
-		perror("arping: setuid");
-		exit(-1);
-	}
-
-	if (prctl(PR_SET_KEEPCAPS, 0) < 0) {
-		perror("arping: prctl");
-		exit(-1);
-	}
-
 	cap_free(cap_p);
 #else
 	euid = geteuid();
diff --git a/clockdiff.c b/clockdiff.c
index f12da2d..540366d 100644
--- a/clockdiff.c
+++ b/clockdiff.c
@@ -536,6 +536,11 @@ usage() {
 }
 
 void drop_rights(void) {
+	if (setuid(getuid())) {
+		perror("clockdiff: setuid");
+		exit(-1);
+	}
+	{
 #ifdef CAPABILITIES
 	cap_t caps = cap_init();
 	if (cap_set_proc(caps)) {
@@ -544,9 +549,6 @@ void drop_rights(void) {
 	}
 	cap_free(caps);
 #endif
-	if (setuid(getuid())) {
-		perror("clockdiff: setuid");
-		exit(-1);
 	}
 }
 
diff --git a/ping_common.c b/ping_common.c
index 39b2c74..08c8582 100644
--- a/ping_common.c
+++ b/ping_common.c
@@ -80,6 +80,21 @@ void limit_capabilities(void)
 	cap_t cap_p;
 	cap_flag_value_t cap_ok;
 
+	if (prctl(PR_SET_KEEPCAPS, 1) < 0) {
+		perror("ping: prctl");
+		exit(-1);
+	}
+
+	if (setuid(getuid()) < 0) {
+		perror("setuid");
+		exit(-1);
+	}
+
+	if (prctl(PR_SET_KEEPCAPS, 0) < 0) {
+		perror("ping: prctl");
+		exit(-1);
+	}
+
 	cap_cur_p = cap_get_proc();
 	if (!cap_cur_p) {
 		perror("ping: cap_get_proc");
@@ -109,21 +124,6 @@ void limit_capabilities(void)
 		exit(-1);
 	}
 
-	if (prctl(PR_SET_KEEPCAPS, 1) < 0) {
-		perror("ping: prctl");
-		exit(-1);
-	}
-
-	if (setuid(getuid()) < 0) {
-		perror("setuid");
-		exit(-1);
-	}
-
-	if (prctl(PR_SET_KEEPCAPS, 0) < 0) {
-		perror("ping: prctl");
-		exit(-1);
-	}
-
 	cap_free(cap_p);
 	cap_free(cap_cur_p);
 #endif
-- 
1.7.6.3