Package: postfix Version: 3.4.1-1 Severity: important Dear Maintainer,
as also reported upstrean at https://marc.info/?t=155301763200003&r=1&w=2 i am running postfix 3.4.1-1 (from debian sid). i recently noticed that mails from multiple senders (most importantly google mail) are being rejected with: > 552 5.3.4 Chunk exceeds message size limit postfix logs: > Mar 19 17:42:48 ngs postfix/smtpd[22671]: warning: 25E74C1: BDAT request from > \ > mail-ed1-f44.google.com[209.85.208.44] exceeds message size limit this happens regardless of the actual message size, even a one-line plaintext message is rejected. /etc/postfix/main.cf has: header_size_limit = 4096000 message_size_limit = 0 downgrading to 3.3.2 fixed the issue. i found the responsible code in postfix-3.4.1/src/smtpd/smtpd.c commenting out that check also fixes the issue. /* Block too large chunks. */ if (state->act_size > var_message_limit - chunk_size) { state->error_mask |= MAIL_ERROR_POLICY; msg_warn("%s: BDAT request from %s exceeds message size limit", state->queue_id ? state->queue_id : "NOQUEUE", state->namaddr); return skip_bdat(state, chunk_size, final_chunk, "552 5.3.4 Chunk exceeds message size limit"); } after some more reading of code, it turns out that this usage of `var_message_limit` is missing the check of `var_message_limit > 0` that in other places enables `0` to mean "no limit", and thus it enforces a limit of 0 with my config :( -- System Information: Debian Release: buster/sid APT prefers unstable APT policy: (500, 'unstable') Architecture: amd64 (x86_64) Kernel: Linux 4.15.0-2-amd64 (SMP w/4 CPU cores) Kernel taint flags: TAINT_WARN Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: sysvinit (via /sbin/init) Versions of packages postfix depends on: ii adduser 3.118 ii cpio 2.12+dfsg-6 ii debconf [debconf-2.0] 1.5.71 ii dpkg 1.19.5 ii e2fsprogs 1.45.0-1 ii libc6 2.28-8 ii libdb5.3 5.3.28+dfsg1-0.6 ii libicu63 63.1-6 ii libsasl2-2 2.1.27+dfsg-1 ii libssl1.1 1.1.1b-1 ii lsb-base 10.2019031300 ii netbase 5.6 ii ssl-cert 1.0.39 Versions of packages postfix recommends: ii python3 3.7.2-1 Versions of packages postfix suggests: ii bsd-mailx [mail-reader] 8.1.2-0.20180807cvs-1 ii libsasl2-modules 2.1.27+dfsg-1 ii mutt [mail-reader] 1.10.1-2 pn postfix-cdb <none> pn postfix-doc <none> pn postfix-ldap <none> pn postfix-lmdb <none> pn postfix-mysql <none> ii postfix-pcre 3.4.1-1 pn postfix-pgsql <none> ii postfix-sqlite 3.4.1-1 ii procmail 3.22-26 pn resolvconf <none> pn ufw <none> -- debconf-show failed
