From 968656cf302ba7f8a3dfaf1013f7d8e80663e63e 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 5/6] 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 Signed-off-by: imxcc --- 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 2b4176cc..035a0cab 100644 --- a/slirp/src/tftp.c +++ b/slirp/src/tftp.c @@ -449,7 +449,11 @@ 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