From: Daniel Wagner <wagi@monom.org>
To: connman@lists.linux.dev
Cc: Nathan Crandall <ncrandall@tesla.com>
Subject: [PATCH 5/6] gweb: Fix OOB write in received_data()
Date: Mon, 1 Aug 2022 10:00:42 +0200 [thread overview]
Message-ID: <20220801080043.4861-5-wagi@monom.org> (raw)
In-Reply-To: <20220801080043.4861-1-wagi@monom.org>
From: Nathan Crandall <ncrandall@tesla.com>
There is a mismatch of handling binary vs. C-string data with memchr
and strlen, resulting in pos, count, and bytes_read to become out of
sync and result in a heap overflow. Instead, do not treat the buffer
as an ASCII C-string. We calculate the count based on the return value
of memchr, instead of strlen.
Fixes: CVE-2022-32292
---
gweb/gweb.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/gweb/gweb.c b/gweb/gweb.c
index 12fcb1d8ab32..13c6c5f25102 100644
--- a/gweb/gweb.c
+++ b/gweb/gweb.c
@@ -918,7 +918,7 @@ static gboolean received_data(GIOChannel *channel, GIOCondition cond,
}
*pos = '\0';
- count = strlen((char *) ptr);
+ count = pos - ptr;
if (count > 0 && ptr[count - 1] == '\r') {
ptr[--count] = '\0';
bytes_read--;
--
2.37.1
