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| author | Willem de Bruijn <willemb@google.com> | 2017-09-26 12:20:17 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-10-21 17:09:03 +0200 |
| commit | 1299f7e17e9e442be49a9b6011f6fe5259960ebb (patch) | |
| tree | ed8a24143fa70410a8a4a25e25f2feab1e9302d7 /net/packet | |
| parent | 1b6c80e797eeadf643861f8340ed5791d813d80c (diff) | |
| download | linux-stable-1299f7e17e9e442be49a9b6011f6fe5259960ebb.tar.gz linux-stable-1299f7e17e9e442be49a9b6011f6fe5259960ebb.tar.bz2 linux-stable-1299f7e17e9e442be49a9b6011f6fe5259960ebb.zip | |
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.c | 6 |
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); |