From: Aki Tuomi <aki.tuomi@open-xchange.com>
Date: Thu, 22 Oct 2020 17:21:41 +0000 (+0300)
Subject: quota: Avoid implicit integer conversion to unsigned in quota calculation
X-Git-Tag: 2.3.13~66
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7a97dfb74f5f2bda6531c6e3584767edce26433f;p=thirdparty%2Fdovecot%2Fcore.git

quota: Avoid implicit integer conversion to unsigned in quota calculation

Deducting negative number from unsigned integer causes
signed integer conversion to unsigned int, which results a
too large positive number. Do calculations using int64 instead.

This did not cause any visible problems, found by
clang integer sanitization.
---

diff --git a/src/plugins/quota/quota.c b/src/plugins/quota/quota.c
index 1457ffe654..ef58e71838 100644
--- a/src/plugins/quota/quota.c
+++ b/src/plugins/quota/quota.c
@@ -1121,12 +1121,12 @@ static void quota_warnings_execute(struct quota_transaction_context *ctx,
 	if (ctx->bytes_used > 0 && bytes_current < (uint64_t)ctx->bytes_used)
 		bytes_before = 0;
 	else
-		bytes_before = bytes_current - ctx->bytes_used;
+		bytes_before = (int64_t)bytes_current - ctx->bytes_used;
 
 	if (ctx->count_used > 0 && count_current < (uint64_t)ctx->count_used)
 		count_before = 0;
 	else
-		count_before = count_current - ctx->count_used;
+		count_before = (int64_t)count_current - ctx->count_used;
 	for (i = 0; i < count; i++) {
 		if (quota_warning_match(&warnings[i],
 					bytes_before, bytes_current,