From: Phil Pennock <pdp@exim.org>
Date: Wed, 31 Jul 2013 22:50:04 +0000 (-0400)
Subject: Fix segfault in stdio with non-SMTP MIME ACL.
X-Git-Tag: exim-4_82_RC1~11
X-Git-Url: https://git.exim.org/exim.git/commitdiff_plain/f4c1088bb7af23e4b613672230868056d46239a5?ds=sidebyside

Fix segfault in stdio with non-SMTP MIME ACL.

When injecting a message locally in non-SMTP mode, and with MIME ACLs
configured, if the ACL rejected the message, Exim would try to
`fprintf(NULL, "%s", the_message)`.  This fixes that.

Most ACLs are plumbed in SMTP-only and looking through the others in
receive.c, they all appear to be safely guarded, so it was just this one
that slipped through.

Crash report and assistance tracking down the root cause from Warren
Baker.
---

diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index f9a376779..d8990102d 100644
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -209,6 +209,10 @@ PP/23 Support safari_ecdhe_ecdsa_bug for openssl_options.
       It's SecureTransport, so affects any MacOS clients which use the
       system-integrated TLS libraries, including email clients.
 
+PP/24 Fix segfault from trying to fprintf() to a NULL stdio FILE* if
+      using a MIME ACL for non-SMTP local injection.
+      Report and assistance in diagnosis by Warren Baker.
+
 
 Exim version 4.80.1
 -------------------
diff --git a/src/ACKNOWLEDGMENTS b/src/ACKNOWLEDGMENTS
index 4474de322..0611b1f99 100644
--- a/src/ACKNOWLEDGMENTS
+++ b/src/ACKNOWLEDGMENTS
@@ -359,6 +359,7 @@ Simon Arlott              Code for outbound SSL-on-connect
                           Patch fixing NUL term/init of DKIM strings
                           Patch fixing dnsdb TXT record handling for DKIM
                           Patch speeding up DomainKeys signing
+Warren Baker              Found crash with MIME ACLs in non-SMTP local injection
 Dmitry Banschikov         Path to check for LDAP TLS initialisation errors
 René Berber               Pointed out mistake in build instructions for QNX
 Johannes Berg             Maintained dynamically loadable module code out-of-tree
diff --git a/src/src/receive.c b/src/src/receive.c
index 48c83db03..993d14917 100644
--- a/src/src/receive.c
+++ b/src/src/receive.c
@@ -1277,9 +1277,10 @@ else if (rc != OK)
 #ifdef EXPERIMENTAL_DCC
   dcc_ok = 0;
 #endif
-  if (smtp_handle_acl_fail(ACL_WHERE_MIME, rc, user_msg, log_msg) != 0)
+  if (smtp_input && smtp_handle_acl_fail(ACL_WHERE_MIME, rc, user_msg, log_msg) != 0) {
     *smtp_yield_ptr = FALSE;    /* No more messsages after dropped connection */
-  *smtp_reply_ptr = US"";       /* Indicate reply already sent */
+    *smtp_reply_ptr = US"";     /* Indicate reply already sent */
+  }
   message_id[0] = 0;            /* Indicate no message accepted */
   return FALSE;                 /* Cause skip to end of receive function */
   }