File CVE-2023-4874-part2.patch of Package mutt

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File CVE-2023-4874-part2.patch of Package mutt

From 4cc3128abdf52c615911589394a03271fddeefc6 Mon Sep 17 00:00:00 2001
From: Kevin McCarthy <kevin@8t8.us>
Date: Mon, 4 Sep 2023 12:50:07 +0800
Subject: [PATCH] Check for NULL userhdrs.

When composing an email, miscellaneous extra headers are stored in a
userhdrs list.  Mutt first checks to ensure each header contains at
least a colon character, passes the entire userhdr field (name, colon,
and body) to the rfc2047 decoder, and safe_strdup()'s the result on
the userhdrs list.  An empty result would from the decode would result
in a NULL headers being added to list.

The previous commit removed the possibility of the decoded header
field being empty, but it's prudent to add a check to the strchr
calls, in case there is another unexpected bug resulting in one.

Thanks to Chenyuan Mi (@morningbread) for discovering the two strchr
crashes, giving a working example draft message, and providing the
stack traces for the two NULL derefences.
---
 sendlib.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sendlib.c b/sendlib.c
--- a/sendlib.c
+++ b/sendlib.c
@@ -2070,7 +2070,7 @@ int mutt_write_rfc822_header (FILE *fp,
   /* Add any user defined headers */
   for (; tmp; tmp = tmp->next)
   {
-    if ((p = strchr (tmp->data, ':')))
+    if ((p = strchr (NONULL (tmp->data), ':')))
     {
       q = p;
 
@@ -2116,7 +2116,7 @@ static void encode_headers (LIST *h)
 
   for (; h; h = h->next)
   {
-    if (!(p = strchr (h->data, ':')))
+    if (!(p = strchr (NONULL (h->data), ':')))
       continue;
 
     i = p - h->data;

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File CVE-2023-4874-part2.patch of Package mutt

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