File ppp-CVE-2014-3158.patch of Package ppp.openSUSE_13.1_Update
From 7658e8257183f062dc01f87969c140707c7e52cb Mon Sep 17 00:00:00 2001
From: Paul Mackerras <paulus@samba.org>
Date: Fri, 1 Aug 2014 16:05:42 +1000
Subject: [PATCH] pppd: Eliminate potential integer overflow in option parsing
When we are reading in a word from an options file, we maintain a count
of the length we have seen so far in 'len', which is an int. When len
exceeds MAXWORDLEN - 1 (i.e. 1023) we cease storing characters in the
buffer but we continue to increment len. Since len is an int, it will
wrap around to -2147483648 after it reaches 2147483647. At that point
our test of (len < MAXWORDLEN-1) will succeed and we will start writing
characters to memory again.
This may enable an attacker to overwrite the heap and thereby corrupt
security-relevant variables. For this reason it has been assigned a
CVE identifier, CVE-2014-3158.
This fixes the bug by ceasing to increment len once it reaches MAXWORDLEN.
Reported-by: Lee Campbell <leecam@google.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
---
pppd/options.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/pppd/options.c b/pppd/options.c
index 45fa742..e9042d1 100644
--- a/pppd/options.c
+++ b/pppd/options.c
@@ -1289,9 +1289,10 @@ getword(f, word, newlinep, filename)
/*
* Store the resulting character for the escape sequence.
*/
- if (len < MAXWORDLEN-1)
+ if (len < MAXWORDLEN) {
word[len] = value;
- ++len;
+ ++len;
+ }
if (!got)
c = getc(f);
@@ -1329,9 +1330,10 @@ getword(f, word, newlinep, filename)
/*
* An ordinary character: store it in the word and get another.
*/
- if (len < MAXWORDLEN-1)
+ if (len < MAXWORDLEN) {
word[len] = c;
- ++len;
+ ++len;
+ }
c = getc(f);
}
--
2.0.4
