Drop bogus IPv6 messages

Drop IPv6 message shorter than what's mentioned in the payload
  length header (+ the size of the IPv6 header). They're invalid and could
  lead to data leakage in icmp6_send_echoreply().

Drop-bogus-IPv6-messages.patch

@@ -0,0 +1,30 @@
+From e8b555c08061ad78920611a5e98ee14fcd967692 Mon Sep 17 00:00:00 2001
+From: Ralf Haferkamp <rhafer@suse.com>
+Date: Fri, 11 Sep 2020 10:55:49 +0800
+Subject: [PATCH] Drop bogus IPv6 messages
+
+Drop IPv6 message shorter than what's mentioned in the playload
+length header (+the size of IPv6 header). They're invalid and could
+lead to data leakage in icmp6_send_echoreply().
+
+diff --git a/slirp/src/ip6_input.c b/slirp/src/ip6_input.c
+index d9d2b7e..c2dce52 100644
+--- a/slirp/src/ip6_input.c
++++ b/slirp/src/ip6_input.c
+@@ -49,6 +49,13 @@ 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);
+-- 
+1.8.3.1
+

qemu.spec

@@ -1,6 +1,6 @@
 Name: qemu
 Version: 4.1.0
-Release: 18
+Release: 19
 Epoch: 2
 Summary: QEMU is a generic and open source machine emulator and virtualizer
 License: GPLv2 and BSD and MIT and CC-BY
@@ -184,6 +184,7 @@ Patch0171: megasas-use-unsigned-type-for-positive-numeric-field.patch
 Patch0172: hw-scsi-megasas-Fix-possible-out-of-bounds-array-acc.patch
 Patch0173: hw-arm-acpi-enable-SHPC-native-hot-plug.patch
 PATCH0174: hw-usb-core-fix-buffer-overflow.patch
+Patch0175: Drop-bogus-IPv6-messages.patch 
 
 BuildRequires: flex
 BuildRequires: bison
@@ -529,6 +530,9 @@ getent passwd qemu >/dev/null || \
 %endif
 
 %changelog
+* Fri Sep 11 2020 Huawei Technologies Co., Ltd <lijiajie11@huawei.com>
+- slirp/src/ip6_input.c: fix out-of-bounds read information vulnerablity
+
 * Thu Aug 27 2020 Huawei Technologies Co., Ltd <lijiajie11@huawei.com>
 - hw/usb/core.c: fix buffer overflow in do_token_setup function