From 6ceab004edfb7c1f0f03701bc2ae443941468fd7 Mon Sep 17 00:00:00 2001 From: Jon Maloy Date: Mon, 17 Aug 2020 22:06:08 -0400 Subject: [PATCH 1/6] Drop bogus IPv6 messages MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Jon Maloy Message-id: <20200817220608.1142611-2-jmaloy@redhat.com> Patchwork-id: 98161 O-Subject: [RHEL-AV-8.3.0 qemu-kvm PATCH 1/1] Drop bogus IPv6 messages Bugzilla: 1867075 RH-Acked-by: Danilo de Paula RH-Acked-by: Philippe Mathieu-Daudé RH-Acked-by: Marc-André Lureau From: Ralf Haferkamp Drop IPv6 message shorter than what's mentioned in the payload length header (+ the size of the IPv6 header). They're invalid an could lead to data leakage in icmp6_send_echoreply(). (cherry picked from libslirp commit c7ede54cbd2e2b25385325600958ba0124e31cc0) Signed-off-by: Jon Maloy Signed-off-by: Danilo C. L. de Paula --- slirp/src/ip6_input.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/slirp/src/ip6_input.c b/slirp/src/ip6_input.c index a83e4f8e3d..f7ef354ee4 100644 --- a/slirp/src/ip6_input.c +++ b/slirp/src/ip6_input.c @@ -56,6 +56,13 @@ void ip6_input(struct mbuf *m) goto bad; } + // Check if the message size is big enough to hold what's + // set in the payload length header. If not this is an invalid + // packet + if (m->m_len < ntohs(ip6->ip_pl) + sizeof(struct ip6)) { + goto bad; + } + /* check ip_ttl for a correct ICMP reply */ if (ip6->ip_hl == 0) { icmp6_send_error(m, ICMP6_TIMXCEED, ICMP6_TIMXCEED_INTRANS); -- 2.27.0