From 49fbfce352a678b538113598cba05c48281174a4 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Date: Wed, 24 Jul 2019 15:53:34 +0100 Subject: [PATCH 09/14] slirp: check sscanf result when emulating ident MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Philippe Mathieu-Daudé Message-id: <20190724155337.25303-2-philmd@redhat.com> Patchwork-id: 89675 O-Subject: [RHEL-8.1.0 qemu-kvm PATCH v2 1/4] slirp: check sscanf result when emulating ident Bugzilla: 1727642 RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Marc-André Lureau RH-Acked-by: Thomas Huth From: William Bowling When emulating ident in tcp_emu, if the strchr checks passed but the sscanf check failed, two uninitialized variables would be copied and sent in the reply, so move this code inside the if(sscanf()) clause. Signed-off-by: William Bowling Cc: qemu-stable@nongnu.org Cc: secalert@redhat.com Message-Id: <1551476756-25749-1-git-send-email-will@wbowling.info> Signed-off-by: Samuel Thibault Reviewed-by: Philippe Mathieu-Daudé (cherry picked from commit d3222975c7d6cda9e25809dea05241188457b113) Fixes: CVE-2019-9824 Signed-off-by: Philippe Mathieu-Daudé Signed-off-by: Danilo C. L. de Paula --- slirp/tcp_subr.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/slirp/tcp_subr.c b/slirp/tcp_subr.c index 1c7eb28..af1b3eb 100644 --- a/slirp/tcp_subr.c +++ b/slirp/tcp_subr.c @@ -665,12 +665,12 @@ tcp_emu(struct socket *so, struct mbuf *m) break; } } + so_rcv->sb_cc = snprintf(so_rcv->sb_data, + so_rcv->sb_datalen, + "%d,%d\r\n", n1, n2); + so_rcv->sb_rptr = so_rcv->sb_data; + so_rcv->sb_wptr = so_rcv->sb_data + so_rcv->sb_cc; } - so_rcv->sb_cc = snprintf(so_rcv->sb_data, - so_rcv->sb_datalen, - "%d,%d\r\n", n1, n2); - so_rcv->sb_rptr = so_rcv->sb_data; - so_rcv->sb_wptr = so_rcv->sb_data + so_rcv->sb_cc; } m_free(m); return 0; -- 1.8.3.1