From 6bd4d80f9274f76eb402ce85aa60729150b39980 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= Date: Thu, 29 Jul 2021 04:56:34 -0400 Subject: [PATCH 09/14] tftp: check tftp_input buffer size MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Marc-André Lureau Message-id: <20210708082537.1550263-6-marcandre.lureau@redhat.com> Patchwork-id: 101823 O-Subject: [RHEL-8.5.0 qemu-kvm PATCH 5/8] tftp: check tftp_input buffer size Bugzilla: 1970843 RH-Acked-by: Stefano Garzarella RH-Acked-by: Eric Blake RH-Acked-by: Stefan Hajnoczi From: Marc-André Lureau Fixes: CVE-2021-3595 Fixes: https://gitlab.freedesktop.org/slirp/libslirp/-/issues/46 Signed-off-by: Marc-André Lureau BZ: https://bugzilla.redhat.com/show_bug.cgi?id=1970843 (cherry picked from commit 3f17948137155f025f7809fdc38576d5d2451c3d) Signed-off-by: Marc-André Lureau Signed-off-by: Miroslav Rezanina --- slirp/src/tftp.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/slirp/src/tftp.c b/slirp/src/tftp.c index 093c2e06a3..07e8f3cb2f 100644 --- a/slirp/src/tftp.c +++ b/slirp/src/tftp.c @@ -444,7 +444,11 @@ 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: -- 2.27.0