libslirp/0004-upd6-check-udp6_input-...

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Diff

From 30feadb676a0792036a0f64309235c5767e2ee76 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= <marcandre.lureau@redhat.com>
Date: Fri, 4 Jun 2021 16:32:55 +0400
Subject: [PATCH 4/7] upd6: check udp6_input buffer size
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Fixes: CVE-2021-3593
Fixes: https://gitlab.freedesktop.org/slirp/libslirp/-/issues/45
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
(cherry picked from commit de71c15de66ba9350bf62c45b05f8fbff166517b)
---
src/udp6.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/src/udp6.c b/src/udp6.c
index fdd8089..236b962 100644
--- a/src/udp6.c
+++ b/src/udp6.c
@@ -29,7 +29,10 @@ void udp6_input(struct mbuf *m)
ip = mtod(m, struct ip6 *);
m->m_len -= iphlen;
m->m_data += iphlen;
- uh = mtod(m, struct udphdr *);
+ uh = mtod_check(m, sizeof(struct udphdr));
+ if (uh == NULL) {
+ goto bad;
+ }
m->m_len += iphlen;
m->m_data -= iphlen;
--
2.29.0