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