File 0180-tcp_emu-Fix-oob-access.patch of Package qemu-testsuite.20749
From: Samuel Thibault <samuel.thibault@ens-lyon.org>
Date: Wed, 8 Jan 2020 00:58:48 +0100
Subject: tcp_emu: Fix oob access
Git-commit: 2655fffed7a9e765bcb4701dd876e9dab975f289
References: bsc#1161066, CVE2020-7039, bsc#1161066, CVS-2020-7039
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 10cf18d650092c291c29ea589756..1ff6d0929269fb0178a27c8d62aa 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)