From: Paul Mackerras <paulus@ozlabs.org>
Date: Sun, 29 Dec 2019 22:32:18 +0000 (+1100)
Subject: pppd: Make sure word read from options file is null-terminated
X-Git-Tag: ppp-2.4.8~4
X-Git-Url: https://git.ozlabs.org/?a=commitdiff_plain;h=c10c3c7cb3e779af5286430d5c9bb835a873ab32;p=ppp.git

pppd: Make sure word read from options file is null-terminated

If a word read from an options file was longer than MAXWORDLEN,
we could pass it to option_error() without null termination,
which could have lead to an out-of-bounds access in vslprintf.
Make sure word[] is null terminated in all cases.

Reported-by: Florian Kohnhäuser <florian@kohnhaeuser.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
---

diff --git a/pppd/options.c b/pppd/options.c
index 5e1489f..f1d2dc9 100644
--- a/pppd/options.c
+++ b/pppd/options.c
@@ -1357,6 +1357,7 @@ getword(f, word, newlinep, filename)
 
 	c = getc(f);
     }
+    word[MAXWORDLEN-1] = 0;	/* make sure word is null-terminated */
 
     /*
      * End of the word: check for errors.