From: Timo Sirainen <tss@iki.fi>
Date: Sun, 22 Sep 2013 04:19:39 +0000 (+0300)
Subject: istream-sized: Fail read() also when the stream is larger than it should have been.
X-Git-Tag: 2.2.6~7
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=825111a4e508289a886a01fccbf22e5cc014eee4;p=thirdparty%2Fdovecot%2Fcore.git

istream-sized: Fail read() also when the stream is larger than it should have been.
---

diff --git a/src/lib/istream-sized.c b/src/lib/istream-sized.c
index 9ef44d1178..b20ac03657 100644
--- a/src/lib/istream-sized.c
+++ b/src/lib/istream-sized.c
@@ -8,6 +8,7 @@ struct sized_istream {
 	struct istream_private istream;
 
 	uoff_t size;
+	bool failed;
 };
 
 static ssize_t i_stream_sized_read(struct istream_private *stream)
@@ -18,6 +19,12 @@ static ssize_t i_stream_sized_read(struct istream_private *stream)
 	ssize_t ret;
 	size_t pos;
 
+	if (sstream->failed) {
+		/* avoid duplicate errors */
+		stream->istream.stream_errno = EINVAL;
+		return -1;
+	}
+
 	if (stream->istream.v_offset +
 	    (stream->pos - stream->skip) >= sstream->size) {
 		stream->istream.eof = TRUE;
@@ -56,6 +63,9 @@ static ssize_t i_stream_sized_read(struct istream_private *stream)
 			stream->iostream.error);
 		pos = left;
 		stream->istream.eof = TRUE;
+		stream->istream.stream_errno = EINVAL;
+		sstream->failed = TRUE;
+		return -1;
 	} else if (!stream->istream.eof) {
 		/* still more to read */
 	} else if (stream->istream.stream_errno == ENOENT) {