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authorWillem de Bruijn <willemb@google.com>2017-09-26 12:20:17 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-10-21 17:09:03 +0200
commit1299f7e17e9e442be49a9b6011f6fe5259960ebb (patch)
treeed8a24143fa70410a8a4a25e25f2feab1e9302d7 /net/packet
parent1b6c80e797eeadf643861f8340ed5791d813d80c (diff)
packet: only test po->has_vnet_hdr once in packet_snd
[ Upstream commit da7c9561015e93d10fe6aab73e9288e0d09d65a6 ] Packet socket option po->has_vnet_hdr can be updated concurrently with other operations if no ring is attached. Do not test the option twice in packet_snd, as the value may change in between calls. A race on setsockopt disable may cause a packet > mtu to be sent without having GSO options set. Fixes: bfd5f4a3d605 ("packet: Add GSO/csum offload support.") Signed-off-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Eric Dumazet <edumazet@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.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index a018f437a8fd..241f69039a72 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1717,7 +1717,7 @@ static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
}
spin_unlock(&po->bind_lock);
- if (err && !refcount_read(&match->sk_ref)) {
+ if (err && !atomic_read(&match->sk_ref)) {
list_del(&match->list);
kfree(match);
}
@@ -2656,6 +2656,7 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
int vnet_hdr_len;
struct packet_sock *po = pkt_sk(sk);
unsigned short gso_type = 0;
+ bool has_vnet_hdr = false;
int hlen, tlen, linear;
int extra_len = 0;
ssize_t n;
@@ -2743,6 +2744,7 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
goto out_unlock;
}
+ has_vnet_hdr = true;
}
if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
@@ -2802,7 +2804,7 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
packet_pick_tx_queue(dev, skb);
- if (po->has_vnet_hdr) {
+ if (has_vnet_hdr) {
if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
u16 s = __virtio16_to_cpu(vio_le(), vnet_hdr.csum_start);
u16 o = __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset);