From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sat, 3 Sep 2011 20:17:39 +0000 (-0400)
Subject: Fix typo in pg_srand48 (srand48 in older branches).
X-Git-Tag: REL9_1_0~28
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=b6cfede8b630db61afa7dd158adde93ba669f429;p=postgresql

Fix typo in pg_srand48 (srand48 in older branches).

">" should be ">>".  This typo results in failure to use all of the bits
of the provided seed.

This might rise to the level of a security bug if we were relying on
srand48 for any security-critical purposes, but we are not --- in fact,
it's not used at all unless the platform lacks srandom(), which is
improbable.  Even on such a platform the exposure seems minimal.

Reported privately by Andres Freund.
---

diff --git a/src/port/erand48.c b/src/port/erand48.c
index 64db7a5376..f58a9808b4 100644
--- a/src/port/erand48.c
+++ b/src/port/erand48.c
@@ -92,7 +92,7 @@ srand48(long seed)
 {
 	_rand48_seed[0] = RAND48_SEED_0;
 	_rand48_seed[1] = (unsigned short) seed;
-	_rand48_seed[2] = (unsigned short) (seed > 16);
+	_rand48_seed[2] = (unsigned short) (seed >> 16);
 	_rand48_mult[0] = RAND48_MULT_0;
 	_rand48_mult[1] = RAND48_MULT_1;
 	_rand48_mult[2] = RAND48_MULT_2;