From: Jeremy Harris <jgh146exb@wizmail.org>
Date: Tue, 12 Feb 2019 16:52:51 +0000 (+0000)
Subject: Fix transport buffer size handling
X-Git-Url: https://git.exim.org/users/heiko/exim.git/commitdiff_plain/1cfa7822ca8928f95160df8742af11fff888ae7e

Fix transport buffer size handling
Broken-by: 59932f7dcd

(cherry picked from commit 05bf16f6217e93594929c8bbbbbc852caf3ed374)
---

diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index 7da07ad46..66c8a7a1b 100644
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -5,6 +5,13 @@ affect Exim's operation, with an unchanged configuration file.  For new
 options, and new features, see the NewStuff file next to this ChangeLog.
 
 
+Since version 4.92
+------------------
+
+JH/06 Fix buggy handling of autoreply bounce_return_size_limit, and a possible
+      buffer overrun for (non-chunking) other transports.
+
+
 Exim version 4.92
 -----------------
 
diff --git a/src/src/transport.c b/src/src/transport.c
index 8ccdd0389..a069b8833 100644
--- a/src/src/transport.c
+++ b/src/src/transport.c
@@ -1115,13 +1115,13 @@ DEBUG(D_transport)
 
 if (!(tctx->options & topt_no_body))
   {
-  int size = size_limit;
+  unsigned long size = size_limit > 0 ? size_limit : ULONG_MAX;
 
   nl_check_length = abs(nl_check_length);
   nl_partial_match = 0;
   if (lseek(deliver_datafile, SPOOL_DATA_START_OFFSET, SEEK_SET) < 0)
     return FALSE;
-  while (  (len = MAX(DELIVER_IN_BUFFER_SIZE, size)) > 0
+  while (  (len = MIN(DELIVER_IN_BUFFER_SIZE, size)) > 0
 	&& (len = read(deliver_datafile, deliver_in_buffer, len)) > 0)
     {
     if (!write_chunk(tctx, deliver_in_buffer, len))