package/slirp: add upstream security fix for CVE-2020-29129 / CVE-2020-29130

While processing ARP/NCSI packets in 'arp_input' or 'ncsi_input'
routines, ensure that pkt_len is large enough to accommodate the
respective protocol headers, lest it should do an OOB access.
Add check to avoid it.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
This commit is contained in:
Peter Korsgaard 2020-11-27 18:25:15 +01:00
parent 7e237b79ad
commit 282fc60ed4
2 changed files with 63 additions and 0 deletions

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@ -0,0 +1,60 @@
From 2e1dcbc0c2af64fcb17009eaf2ceedd81be2b27f Mon Sep 17 00:00:00 2001
From: Prasad J Pandit <pjp@fedoraproject.org>
Date: Thu, 26 Nov 2020 19:27:06 +0530
Subject: [PATCH] slirp: check pkt_len before reading protocol header
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
While processing ARP/NCSI packets in 'arp_input' or 'ncsi_input'
routines, ensure that pkt_len is large enough to accommodate the
respective protocol headers, lest it should do an OOB access.
Add check to avoid it.
CVE-2020-29129 CVE-2020-29130
QEMU: slirp: out-of-bounds access while processing ARP/NCSI packets
-> https://www.openwall.com/lists/oss-security/2020/11/27/1
Reported-by: Qiuhao Li <Qiuhao.Li@outlook.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Message-Id: <20201126135706.273950-1-ppandit@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
---
src/ncsi.c | 4 ++++
src/slirp.c | 4 ++++
2 files changed, 8 insertions(+)
diff --git a/src/ncsi.c b/src/ncsi.c
index 3c1dfef..75dcc08 100644
--- a/src/ncsi.c
+++ b/src/ncsi.c
@@ -148,6 +148,10 @@ void ncsi_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
uint32_t checksum;
uint32_t *pchecksum;
+ if (pkt_len < ETH_HLEN + sizeof(struct ncsi_pkt_hdr)) {
+ return; /* packet too short */
+ }
+
memset(ncsi_reply, 0, sizeof(ncsi_reply));
memset(reh->h_dest, 0xff, ETH_ALEN);
diff --git a/src/slirp.c b/src/slirp.c
index 9bead0c..abb6f9a 100644
--- a/src/slirp.c
+++ b/src/slirp.c
@@ -860,6 +860,10 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
return;
}
+ if (pkt_len < ETH_HLEN + sizeof(struct slirp_arphdr)) {
+ return; /* packet too short */
+ }
+
ar_op = ntohs(ah->ar_op);
switch (ar_op) {
case ARPOP_REQUEST:
--
2.20.1

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@ -14,4 +14,7 @@ SLIRP_LICENSE_FILES = COPYRIGHT
SLIRP_INSTALL_STAGING = YES
SLIRP_DEPENDENCIES = libglib2
# 0001-slirp-check-pkt_len-before-reading-protocol-header.patch
SLIRP_IGNORE_CVES += CVE-2020-29129 CVE-2020-29130
$(eval $(meson-package))