From 4199ce23fd3df23daccbf961b2ff1a2d42f89519 Mon Sep 17 00:00:00 2001
From: Mark Wooding <mdw@distorted.org.uk>
Date: Sat, 23 Dec 2023 14:18:18 +0000
Subject: [PATCH] rand/rand.c: Rearrange some comparisons to avoid arithmetic
 overflow.

---
 rand/rand.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/rand/rand.c b/rand/rand.c
index 90e81930..0d0650eb 100644
--- a/rand/rand.c
+++ b/rand/rand.c
@@ -413,7 +413,7 @@ void rand_get(rand_pool *r, void *p, size_t sz)
   if (!sz)
     return;
   for (;;) {
-    if (r->o + sz <= RAND_BUFSZ) {
+    if (sz <= RAND_BUFSZ - r->o) {
       memcpy(o, r->buf + r->o, sz);
       r->o += sz;
       break;
@@ -475,7 +475,7 @@ void rand_getgood(rand_pool *r, void *p, size_t sz)
 	chunk = r->obits / 8;
     }
 
-    if (chunk + r->o <= RAND_BUFSZ) {
+    if (chunk <= RAND_BUFSZ - r->o) {
       memcpy(o, r->buf + r->o, chunk);
       r->o += chunk;
     } else {
-- 
2.11.0