On Wed, Nov 04, 2020 at 10:32:57AM -0500, Andreas Weigel wrote:
> Hi everyone,
>
> I think I stumbled upon a problem with postfix 3.5.X and very long
> header lines. To reproduce, I build a very simple setup with two VMs:
> - "A" running postfix 3.3.0 (xubuntu 18.04 package)
> - "B" running postfix 3.5.6 (xubuntu 20.10 package)
>
Yes, this looks like a bug introduced in Postfix 3.5 via:
20190615
Feature: SMTP/LMTP client support for 'D', 'O', 'R', 'X'
flags similar to the pipe(8) daemon, to produce Delivered-To,
X-Original-To, and Return-Path headers, and to indicate
final delivery. Files: smtp/smtp.c, smtp/smtp.h, smtp/smtp_misc.c,
smtp/smtp_proto.c, smtp/smtp_rcpt.c.
The new code that handles adding those headers was also reused to emit
all headers, incorrectly including logical headers that span multiple
physical lines:
https://github.com/vdukhovni/postfix/commit/2ff7c91a461a093ff7a04a2ea9d1d3c0f1376243#diff-0e8480070aeb81a843eb195dc510a864f404ea03c5cdd597c6e00ab98d08de1cR2307-R2313
The value of "rec_type" needs to be passed to smtp_out_raw_or_mime() and
the output processed accordingly. Untested patch below:
diff --git a/src/smtp/smtp_proto.c b/src/smtp/smtp_proto.c
index 7fd63486..2bb3d3ca 100644
--- a/src/smtp/smtp_proto.c
+++ b/src/smtp/smtp_proto.c
@@ -1389,17 +1389,17 @@ static void smtp_mime_fail(SMTP_STATE *state, int
mime_errs)
/* smtp_out_raw_or_mime - output buffer, raw output or MIME-aware */
-static int smtp_out_raw_or_mime(SMTP_STATE *state, VSTRING *buf)
+static int smtp_out_raw_or_mime(SMTP_STATE *state, int rec_type, VSTRING *buf)
{
SMTP_SESSION *session = state->session;
int mime_errs;
if (session->mime_state == 0) {
- smtp_text_out((void *) state, REC_TYPE_NORM, vstring_str(buf),
+ smtp_text_out((void *) state, rec_type, vstring_str(buf),
VSTRING_LEN(buf), (off_t) 0);
} else {
mime_errs =
- mime_state_update(session->mime_state, REC_TYPE_NORM,
+ mime_state_update(session->mime_state, rec_type,
vstring_str(buf), VSTRING_LEN(buf));
if (mime_errs) {
smtp_mime_fail(state, mime_errs);
@@ -1423,7 +1423,7 @@ static int smtp_out_add_header(SMTP_STATE *state, const
char *label,
vstring_str(session->scratch2),
QUOTE_FLAG_DEFAULT | QUOTE_FLAG_APPEND);
vstring_strcat(session->scratch, gt);
- return (smtp_out_raw_or_mime(state, session->scratch));
+ return (smtp_out_raw_or_mime(state, REC_TYPE_NORM, session->scratch));
}
/* smtp_out_add_headers - output additional headers, uses session->scratch* */
@@ -2307,7 +2307,8 @@ static int smtp_loop(SMTP_STATE *state, NOCLOBBER int
send_state,
while ((rec_type = rec_get(state->src, session->scratch, 0)) >
0) {
if (rec_type != REC_TYPE_NORM && rec_type != REC_TYPE_CONT)
break;
- if (smtp_out_raw_or_mime(state, session->scratch) < 0)
+ if (smtp_out_raw_or_mime(state, rec_type,
+ session->scratch) < 0)
RETURN(0);
prev_type = rec_type;
}
--
Viktor.
