From 5c2c5496083fa549e1dff903413bb6136fc19d8d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= Date: Fri, 17 Jan 2020 12:07:56 +0100 Subject: [PATCH 1/4] tcp_emu: Fix oob access MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Marc-André Lureau Message-id: <20200117120758.1076549-2-marcandre.lureau@redhat.com> Patchwork-id: 93399 O-Subject: [RHEL-AV-8.1.0 qemu-kvm + RHEL-AV-8.2.0 qemu-kvm PATCH 1/3] tcp_emu: Fix oob access Bugzilla: 1791568 RH-Acked-by: Philippe Mathieu-Daudé RH-Acked-by: Stefano Garzarella RH-Acked-by: Stefan Hajnoczi From: Samuel Thibault The main loop only checks for one available byte, while we sometimes need two bytes. [ MA - minor conflict, CHANGELOG.md absent ] (cherry picked from libslirp commit 2655fffed7a9e765bcb4701dd876e9dab975f289) Signed-off-by: Marc-André Lureau Signed-off-by: Miroslav Rezanina --- slirp/src/tcp_subr.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/slirp/src/tcp_subr.c b/slirp/src/tcp_subr.c index d6dd133..cbecd64 100644 --- a/slirp/src/tcp_subr.c +++ b/slirp/src/tcp_subr.c @@ -886,6 +886,9 @@ int 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 @@ -901,6 +904,10 @@ int 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 = (((uint8_t *)bptr)[0] << 8) + ((uint8_t *)bptr)[1]; if (lport < 6970) lport += 256; /* don't know why */ -- 1.8.3.1