File 0150-tcp_emu-Fix-oob-access.patch of Package qemu.15022

From 0f38924c62f0892cadfb55dc96f85d32ce3f2702 Mon Sep 17 00:00:00 2001
From: Samuel Thibault <samuel.thibault@ens-lyon.org>
Date: Wed, 8 Jan 2020 00:58:48 +0100
Subject: [PATCH] tcp_emu: Fix oob access

Git-commit: 2655fffed7a9e765bcb4701dd876e9dab975f289
References: bsc#1161066, CVE-2020-7039, bsc#1163018, CVE-2020-8608

The main loop only checks for one available byte, while we sometimes
need two bytes.

Signed-off-by: Bruce Rogers <brogers@suse.com>
---
 slirp/tcp_subr.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/slirp/tcp_subr.c b/slirp/tcp_subr.c
index 10cf18d650..1ff6d09292 100644
--- a/slirp/tcp_subr.c
+++ b/slirp/tcp_subr.c
@@ -892,6 +892,9 @@ tcp_emu(struct socket *so, struct mbuf *m)
 				break;
 
 			 case 5:
+				if (bptr == m->m_data + m->m_len - 1)
+					return 1; /* We need two bytes */
+
 				/*
 				 * The difference between versions 1.0 and
 				 * 2.0 is here. For future versions of
@@ -907,6 +910,10 @@ tcp_emu(struct socket *so, struct mbuf *m)
 				/* This is the field containing the port
 				 * number that RA-player is listening to.
 				 */
+
+				if (bptr == m->m_data + m->m_len - 1)
+					return 1; /* We need two bytes */
+
 				lport = (((u_char*)bptr)[0] << 8)
 				+ ((u_char *)bptr)[1];
 				if (lport < 6970)