Fix CVE-2017-7853:

https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-7853
https://savannah.gnu.org/support/index.php?109265

Patch copied from upstream source repository:

https://git.savannah.gnu.org/cgit/osip.git/commit/?id=1ae06daf3b2375c34af23083394a6f010be24a45

From 1ae06daf3b2375c34af23083394a6f010be24a45 Mon Sep 17 00:00:00 2001
From: Aymeric Moizard <amoizard@gmail.com>
Date: Tue, 21 Feb 2017 17:16:26 +0100
Subject: [PATCH]  * fix bug report: sr #109265: SIP message body length
 underflow in libosip2-4.1.0    https://savannah.gnu.org/support/?109265   
 also applicable to current latest version

---
 src/osipparser2/osip_message_parse.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/osipparser2/osip_message_parse.c b/src/osipparser2/osip_message_parse.c
index 1628c60..aa35446 100644
--- a/src/osipparser2/osip_message_parse.c
+++ b/src/osipparser2/osip_message_parse.c
@@ -784,6 +784,12 @@ msg_osip_body_parse (osip_message_t * sip, const char *start_of_buf, const char
     if ('\n' == start_of_body[0] || '\r' == start_of_body[0])
       start_of_body++;
 
+    /* if message body is empty or contains a single CR/LF */
+    if (end_of_body <= start_of_body) {
+      osip_free (sep_boundary);
+      return OSIP_SYNTAXERROR;
+    }
+
     body_len = end_of_body - start_of_body;
 
     /* Skip CR before end boundary. */
-- 
2.13.1

c5b0fd2de9ed1eaa13461bd31fe1'>commit</a><a href='/guix/diff/etc/committer.scm.in?id=f6943167b4a1c5b0fd2de9ed1eaa13461bd31fe1'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/etc/committer.scm.in'>
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<div class='path'>path: <a href='/guix/log/?id=f6943167b4a1c5b0fd2de9ed1eaa13461bd31fe1'>root</a>/<a href='/guix/log/etc?id=f6943167b4a1c5b0fd2de9ed1eaa13461bd31fe1'>etc</a>/<a href='/guix/log/etc/committer.scm.in?id=f6943167b4a1c5b0fd2de9ed1eaa13461bd31fe1'>committer.scm.in</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/etc/committer.scm.in?id=f6943167b4a1c5b0fd2de9ed1eaa13461bd31fe1&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2022-05-31 14:52:13 -0400'>2022-05-31</span></td><td><a href='/guix/commit/etc/committer.scm.in?id=5e6efdfeecae82315862ebee95ce02bb868eb0f3'>etc/committer: Teach it how to commit package removal.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/committer.scm.in (hunk-types): New variable.
(&lt;hunk&gt;): Rename hunk-definition? getter to 'hunk-type'.
(diff-info): Mute a git warning by separating file names from arguments with
'--'.  Rename the 'definitions?' variable to 'type'.
Use the 'addition type when a new package addition is detected, 'removal when
removed else #f.
(add-commit-message): Re-indent.
(remove-commit-message): New procedure.
(main)[definitions]: Make commit message conditional depending on whether it
is an addition or removal.
[changes]: Adjust indentation.
</span></span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2022-05-31 14:52:13 -0400'>2022-05-31</span></td><td><a href='/guix/commit/etc/committer.scm.in?id=6c956243bc7972644e947563a45e33d73042afdc'>etc/committer: Prefix (sxml xpath) symbols to avoid name conflict.</a><span class='msg-avail'>...<span class='msg-tooltip'>This avoids a naming conflict for 'filter', provided by both (srfi srfi-1)
and (sxml xpath).

* etc/committer.scm.in: Use 'use-modules' instead of 'import', and use a
prefix for the (sxml xpath) module.
(new-sexp): Adjust accordingly.
(change-commit-message): Likewise.
</span></span></td><td>Maxim Cournoyer</td></tr>