From: Aki Tuomi <aki.tuomi@open-xchange.com>
Date: Thu, 13 Aug 2020 08:35:17 +0000 (+0300)
Subject: lib: rand - Fix random number bounding
X-Git-Tag: 2.3.13~219
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=0589ced75103019965a2d1cc46036678e47cbec7;p=thirdparty%2Fdovecot%2Fcore.git

lib: rand - Fix random number bounding
---

diff --git a/src/lib/rand.c b/src/lib/rand.c
index ff7675dcc6..9fbcac37a7 100644
--- a/src/lib/rand.c
+++ b/src/lib/rand.c
@@ -31,7 +31,8 @@ uint32_t i_rand_limit(uint32_t upper_bound)
 {
 	i_assert(upper_bound > 0);
 
-	uint32_t val, min = -upper_bound % upper_bound;
+	uint32_t val;
+	uint32_t min = ~(upper_bound - 1) % upper_bound;
 	while((val = i_rand()) < min);
 	return val % upper_bound;
 }