diff options
| author | Marissa Wall <marissaw@google.com> | 2017-11-16 16:56:10 -0800 |
|---|---|---|
| committer | Shirle Yuen <shirleyshukyee@google.com> | 2018-08-05 16:36:34 -0700 |
| commit | 244e23c69481b8ec2b0df542f77e6808c16b7bbc (patch) | |
| tree | 4eb575f31497a05766fd82f7a5a8c2a871c2932f | |
| parent | 7099a9736ab73a32b00c71ec8ef7d339cf12c000 (diff) | |
| download | qcom-msm8x09-v3.10-244e23c69481b8ec2b0df542f77e6808c16b7bbc.tar.gz | |
BACKPORT: packet: in packet_do_bind, test fanout with bind_lock held
[ Upstream commit 4971613c1639d8e5f102c4e797c3bf8f83a5a69e ]
Once a socket has po->fanout set, it remains a member of the group
until it is destroyed. The prot_hook must be constant and identical
across sockets in the group.
If fanout_add races with packet_do_bind between the test of po->fanout
and taking the lock, the bind call may make type or dev inconsistent
with that of the fanout group.
Hold po->bind_lock when testing po->fanout to avoid this race.
I had to introduce artificial delay (local_bh_enable) to actually
observe the race.
Bug: 111289931
Change-Id: I8944e2bb562f72f8e1d50ad4bc60a3bce82cf089
Fixes: dc99f600698d ("packet: Add fanout 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>
Signed-off-by: Marissa Wall <marissaw@google.com>
Git-repo: https://android.googlesource.com/kernel/common
Git-commit: 4e2a95fdd6c9d298e32f55852da811fcf6924c06
Signed-off-by: Ashwanth Goli <ashwanth@codeaurora.org>
(cherry picked from commit d6ccf8acddbc2bb66594e0f7cae4d2c974bea2d4)
| -rw-r--r-- | net/packet/af_packet.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index a867351bc19..65aff0f7b3e 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2493,17 +2493,20 @@ static int packet_release(struct socket *sock) static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol) { struct packet_sock *po = pkt_sk(sk); + int ret = 0; + + lock_sock(sk); + + spin_lock(&po->bind_lock); if (po->fanout) { if (dev) dev_put(dev); - return -EINVAL; + ret = -EINVAL; + goto out_unlock; } - lock_sock(sk); - - spin_lock(&po->bind_lock); unregister_prot_hook(sk, true); po->num = protocol; @@ -2530,7 +2533,7 @@ static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protoc out_unlock: spin_unlock(&po->bind_lock); release_sock(sk); - return 0; + return ret; } /* |