From 31aaf902aa6ba31ab8f41543b2d4da8c01f3b861 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= Date: Fri, 4 Jun 2021 16:34:30 +0400 Subject: [PATCH 5/7] tftp: check tftp_input buffer size MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fixes: CVE-2021-3595 Fixes: https://gitlab.freedesktop.org/slirp/libslirp/-/issues/46 Signed-off-by: Marc-André Lureau (cherry picked from commit 3f17948137155f025f7809fdc38576d5d2451c3d) --- src/tftp.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/src/tftp.c b/src/tftp.c index c6950ee..e06911d 100644 --- a/src/tftp.c +++ b/src/tftp.c @@ -446,7 +446,11 @@ static void tftp_handle_error(Slirp *slirp, struct sockaddr_storage *srcsas, void tftp_input(struct sockaddr_storage *srcsas, struct mbuf *m) { - struct tftp_t *tp = (struct tftp_t *)m->m_data; + struct tftp_t *tp = mtod_check(m, offsetof(struct tftp_t, x.tp_buf)); + + if (tp == NULL) { + return; + } switch (ntohs(tp->tp_op)) { case TFTP_RRQ: -- 2.29.0