diff options
Diffstat (limited to 'net-packet-fix-overflow-in-tpacket_rcv.patch')
| -rw-r--r-- | net-packet-fix-overflow-in-tpacket_rcv.patch | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/net-packet-fix-overflow-in-tpacket_rcv.patch b/net-packet-fix-overflow-in-tpacket_rcv.patch new file mode 100644 index 000000000..6c6868f5c --- /dev/null +++ b/net-packet-fix-overflow-in-tpacket_rcv.patch @@ -0,0 +1,59 @@ +From 00c393ea14d12a4ef490a6aedf0fa6bfc2bfe8c3 Mon Sep 17 00:00:00 2001 +From: Sasha Levin <sashal@kernel.org> +Date: Thu, 3 Sep 2020 21:05:28 -0700 +Subject: net/packet: fix overflow in tpacket_rcv + +From: Or Cohen <orcohen@paloaltonetworks.com> + +[ Upstream commit acf69c946233259ab4d64f8869d4037a198c7f06 ] + +Using tp_reserve to calculate netoff can overflow as +tp_reserve is unsigned int and netoff is unsigned short. + +This may lead to macoff receving a smaller value then +sizeof(struct virtio_net_hdr), and if po->has_vnet_hdr +is set, an out-of-bounds write will occur when +calling virtio_net_hdr_from_skb. + +The bug is fixed by converting netoff to unsigned int +and checking if it exceeds USHRT_MAX. + +This addresses CVE-2020-14386 + +Fixes: 8913336a7e8d ("packet: add PACKET_RESERVE sockopt") +Signed-off-by: Or Cohen <orcohen@paloaltonetworks.com> +Signed-off-by: Eric Dumazet <edumazet@google.com> +Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> +Signed-off-by: Sasha Levin <sashal@kernel.org> +--- + net/packet/af_packet.c | 7 ++++++- + 1 file changed, 6 insertions(+), 1 deletion(-) + +diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c +index 301f41d4929bd..82f7802983797 100644 +--- a/net/packet/af_packet.c ++++ b/net/packet/af_packet.c +@@ -2170,7 +2170,8 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, + int skb_len = skb->len; + unsigned int snaplen, res; + unsigned long status = TP_STATUS_USER; +- unsigned short macoff, netoff, hdrlen; ++ unsigned short macoff, hdrlen; ++ unsigned int netoff; + struct sk_buff *copy_skb = NULL; + struct timespec64 ts; + __u32 ts_status; +@@ -2239,6 +2240,10 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, + } + macoff = netoff - maclen; + } ++ if (netoff > USHRT_MAX) { ++ atomic_inc(&po->tp_drops); ++ goto drop_n_restore; ++ } + if (po->tp_version <= TPACKET_V2) { + if (macoff + snaplen > po->rx_ring.frame_size) { + if (po->copy_thresh && +-- +2.25.1 + |