diff options
| author | Benjamin Poirier <bpoirier@suse.com> | 2017-08-28 14:29:41 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-09-20 08:19:54 +0200 |
| commit | 8c623e5d03692dc478277185a0b907d53aea1b43 (patch) | |
| tree | b6f92d9bd9ac180c4c0d3c6a42740809d642d539 /net/packet | |
| parent | 2b3bd5972a5ce434b3f2211181e72033efe018d9 (diff) | |
packet: Don't write vnet header beyond end of buffer
[ Upstream commit edbd58be15a957f6a760c4a514cd475217eb97fd ]
... which may happen with certain values of tp_reserve and maclen.
Fixes: 58d19b19cd99 ("packet: vnet_hdr support for tpacket_rcv")
Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
Cc: Willem de Bruijn <willemb@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/packet')
| -rw-r--r-- | net/packet/af_packet.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index ae7bfd26cd91..35ba4b60d927 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2151,6 +2151,7 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, struct timespec ts; __u32 ts_status; bool is_drop_n_account = false; + bool do_vnet = false; /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT. * We may add members to them until current aligned size without forcing @@ -2201,8 +2202,10 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, netoff = TPACKET_ALIGN(po->tp_hdrlen + (maclen < 16 ? 16 : maclen)) + po->tp_reserve; - if (po->has_vnet_hdr) + if (po->has_vnet_hdr) { netoff += sizeof(struct virtio_net_hdr); + do_vnet = true; + } macoff = netoff - maclen; } if (po->tp_version <= TPACKET_V2) { @@ -2219,8 +2222,10 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, skb_set_owner_r(copy_skb, sk); } snaplen = po->rx_ring.frame_size - macoff; - if ((int)snaplen < 0) + if ((int)snaplen < 0) { snaplen = 0; + do_vnet = false; + } } } else if (unlikely(macoff + snaplen > GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) { @@ -2233,6 +2238,7 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, if (unlikely((int)snaplen < 0)) { snaplen = 0; macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len; + do_vnet = false; } } spin_lock(&sk->sk_receive_queue.lock); @@ -2258,7 +2264,7 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, } spin_unlock(&sk->sk_receive_queue.lock); - if (po->has_vnet_hdr) { + if (do_vnet) { if (__packet_rcv_vnet(skb, h.raw + macoff - sizeof(struct virtio_net_hdr))) { spin_lock(&sk->sk_receive_queue.lock); |