From: Timo Sirainen <timo.sirainen@dovecot.fi>
Date: Tue, 7 Feb 2017 18:41:41 +0000 (+0200)
Subject: quota: Make sure quota_warning doesn't wrap "quota before" value.
X-Git-Tag: 2.3.0.rc1~2156
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cd337e465bf8bf33d556fc397787d1519d1cef07;p=thirdparty%2Fdovecot%2Fcore.git

quota: Make sure quota_warning doesn't wrap "quota before" value.

This could happen in some race conditions (and with bugs).
---

diff --git a/src/plugins/quota/quota.c b/src/plugins/quota/quota.c
index 143783162c..0fd66ee2b3 100644
--- a/src/plugins/quota/quota.c
+++ b/src/plugins/quota/quota.c
@@ -951,8 +951,15 @@ static void quota_warnings_execute(struct quota_transaction_context *ctx,
 			       &count_current, &count_limit) < 0)
 		return;
 
-	bytes_before = bytes_current - ctx->bytes_used;
-	count_before = count_current - ctx->count_used;
+	if (ctx->bytes_used > 0 && bytes_current < (uint64_t)ctx->bytes_used)
+		bytes_before = 0;
+	else
+		bytes_before = 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;
 	for (i = 0; i < count; i++) {
 		if (quota_warning_match(&warnings[i],
 					bytes_before, bytes_current,