From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Wed, 18 Aug 2021 07:05:02 +0000 (+0900)
Subject: creds-util: fix possible divide-by-zero
X-Git-Tag: v250-rc1~807
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=7ff592a4542f611088e63ab27191a40fcd064e7c;p=thirdparty%2Fsystemd.git

creds-util: fix possible divide-by-zero

input_size may be zero.

Fixes #20469.
---

diff --git a/src/shared/creds-util.c b/src/shared/creds-util.c
index 3bc5fbef512..9980cd93a92 100644
--- a/src/shared/creds-util.c
+++ b/src/shared/creds-util.c
@@ -667,11 +667,11 @@ int encrypt_credential_and_warn(
         p += tsz;
         assert(p <= output_size);
 
-        if (DEBUG_LOGGING) {
+        if (DEBUG_LOGGING && input_size > 0) {
                 size_t base64_size;
 
                 base64_size = DIV_ROUND_UP(p * 4, 3); /* Include base64 size increase in debug output */
-
+                assert(base64_size >= input_size);
                 log_debug("Input of %zu bytes grew to output of %zu bytes (+%2zu%%).", input_size, base64_size, base64_size * 100 / input_size - 100);
         }