From: Stephan Bosch <stephan.bosch@open-xchange.com>
Date: Mon, 27 Sep 2021 22:51:03 +0000 (+0200)
Subject: lib: ostream-wrapper - Make sure o_stream_finish() has stream_errno != 0 when -1... 
X-Git-Tag: 2.3.18~273
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3c05dcfa5844f99fa9572079cf0937b3ec8cb40a;p=thirdparty%2Fdovecot%2Fcore.git

lib: ostream-wrapper - Make sure o_stream_finish() has stream_errno != 0 when -1 is to be returned.

Fixes:

Panic: file ostream.c: line 209 (o_stream_flush): assertion failed: (stream->stream_errno != 0)
---

diff --git a/src/lib/ostream-wrapper.c b/src/lib/ostream-wrapper.c
index 566a977cbe..dfd669946f 100644
--- a/src/lib/ostream-wrapper.c
+++ b/src/lib/ostream-wrapper.c
@@ -68,14 +68,22 @@ static inline bool wrapper_ostream_is_filled(struct wrapper_ostream *wostream)
 
 /* Handle error in the underlying output stream (the parent). */
 static void
-wrapper_ostream_handle_parent_error(struct wrapper_ostream *wostream)
+wrapper_ostream_copy_parent_error(struct wrapper_ostream *wostream)
 {
 	i_assert(wostream->output != NULL);
+	i_assert(wostream->output->stream_errno != 0);
 
 	wostream->ostream.ostream.stream_errno =
 		wostream->output->stream_errno;
 	wostream->ostream.ostream.overflow =
 		wostream->output->overflow;
+}
+
+static void
+wrapper_ostream_handle_parent_error(struct wrapper_ostream *wostream)
+{
+	wrapper_ostream_copy_parent_error(wostream);
+
 	if (wostream->output->closed)
 		o_stream_close(&wostream->ostream.ostream);
 
@@ -244,11 +252,16 @@ static int wrapper_ostream_finish(struct wrapper_ostream *wostream)
 
 	/* Finished sending payload; now also finish the underlying output. */
 	ret = wrapper_ostream_output_finish(wostream);
-	if (ret <= 0)
+	if (ret == 0)
 		return ret;
-
-	if (wrapper_ostream_handle_pending_error(wostream) < 0)
+	if (ret < 0 && wostream->ostream.ostream.stream_errno != 0) {
+		wrapper_ostream_copy_parent_error(wostream);
+		return -1;
+	}
+	if (wrapper_ostream_handle_pending_error(wostream) < 0 || ret < 0) {
+		i_assert(wostream->ostream.ostream.stream_errno != 0);
 		return -1;
+	}
 	wrapper_ostream_output_close(wostream);
 	return 1;
 }
@@ -933,6 +946,7 @@ static int wrapper_ostream_flush(struct ostream_private *stream)
 	if (wostream->output_closed) {
 		i_assert(ret < 0 || ostream->stream_errno == 0 ||
 			 ostream->closed);
+		i_assert(ret >= 0 || ostream->stream_errno != 0);
 		o_stream_unref(&ostream);
 		return (ret >= 0 ? 1 : -1);
 	}
@@ -948,8 +962,9 @@ static int wrapper_ostream_flush(struct ostream_private *stream)
 	} else {
 		o_stream_uncork(wostream->output);
 	}
-	o_stream_unref(&ostream);
 
+	i_assert(ret >= 0 || ostream->stream_errno != 0);
+	o_stream_unref(&ostream);
 	return ret;
 }