From 6126f7a53c57485a9a29ddd772765695f23c92e6 Mon Sep 17 00:00:00 2001
From: Petr Uzel
Date: Thu, 3 May 2012 21:02:01 +0200
Subject: libuuid: avoid double open and leaking descriptor

We are opening /dev/urandom twice in uuid_generate(): first to check if
the file is available and then later __uuid_generate_random() again to
actually get the random data. Moreover, descriptor from the first open
is leaking.

Fix by passign the descriptor down the stack and reusing it there.

References: http://marc.info/?l=util-linux-ng&m=133406051131131&w=2

Signed-off-by: Petr Uzel <petr.uzel@suse.cz>
---
 libuuid/src/gen_uuid.c | 17 ++++++++++-------
 libuuid/src/uuidd.h    |  2 +-
 2 files changed, 11 insertions(+), 8 deletions(-)

(limited to 'libuuid')

diff --git a/libuuid/src/gen_uuid.c b/libuuid/src/gen_uuid.c
index 8ff41291c..76f1bbdad 100644
--- a/libuuid/src/gen_uuid.c
+++ b/libuuid/src/gen_uuid.c
@@ -277,7 +277,7 @@ static int get_clock(uint32_t *clock_high, uint32_t *clock_low,
 	}
 
 	if ((last.tv_sec == 0) && (last.tv_usec == 0)) {
-		random_get_bytes(&clock_seq, sizeof(clock_seq));
+		random_get_bytes(&clock_seq, sizeof(clock_seq), -1);
 		clock_seq &= 0x3FFF;
 		gettimeofday(&last, 0);
 		last.tv_sec--;
@@ -434,7 +434,7 @@ int __uuid_generate_time(uuid_t out, int *num)
 
 	if (!has_init) {
 		if (get_node_id(node_id) <= 0) {
-			random_get_bytes(node_id, 6);
+			random_get_bytes(node_id, 6, -1);
 			/*
 			 * Set multicast bit, to prevent conflicts
 			 * with IEEE 802 addresses obtained from
@@ -520,7 +520,7 @@ int uuid_generate_time_safe(uuid_t out)
 }
 
 
-void __uuid_generate_random(uuid_t out, int *num)
+void __uuid_generate_random(uuid_t out, int *num, int fd)
 {
 	uuid_t	buf;
 	struct uuid uu;
@@ -532,7 +532,7 @@ void __uuid_generate_random(uuid_t out, int *num)
 		n = *num;
 
 	for (i = 0; i < n; i++) {
-		random_get_bytes(buf, sizeof(buf));
+		random_get_bytes(buf, sizeof(buf), fd);
 		uuid_unpack(buf, &uu);
 
 		uu.clock_seq = (uu.clock_seq & 0x3FFF) | 0x8000;
@@ -548,7 +548,7 @@ void uuid_generate_random(uuid_t out)
 	int	num = 1;
 	/* No real reason to use the daemon for random uuid's -- yet */
 
-	__uuid_generate_random(out, &num);
+	__uuid_generate_random(out, &num, -1);
 }
 
 
@@ -560,8 +560,11 @@ void uuid_generate_random(uuid_t out)
  */
 void uuid_generate(uuid_t out)
 {
-	if (random_get_fd() >= 0)
-		uuid_generate_random(out);
+	int	fd;
+	int	num = 1;
+
+	if ((fd = random_get_fd()) >= 0)
+		__uuid_generate_random(out, &num, fd);
 	else
 		uuid_generate_time(out);
 }
diff --git a/libuuid/src/uuidd.h b/libuuid/src/uuidd.h
index 27b79c216..2e19522df 100644
--- a/libuuid/src/uuidd.h
+++ b/libuuid/src/uuidd.h
@@ -49,6 +49,6 @@
 #define UUIDD_MAX_OP			UUIDD_OP_BULK_RANDOM_UUID
 
 extern int __uuid_generate_time(uuid_t out, int *num);
-extern void __uuid_generate_random(uuid_t out, int *num);
+extern void __uuid_generate_random(uuid_t out, int *num, int fd);
 
 #endif /* _UUID_UUID_H */
-- 
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