diff options
| author | Sowmini Varadhan | 2016-07-14 12:51:01 +0200 |
|---|---|---|
| committer | David S. Miller | 2016-07-15 20:36:57 +0200 |
| commit | a93d01f5777e99f24b5b3948e06673ada148337c (patch) | |
| tree | 1c8f2320199c9d7e0881fd6020c99d8fd967662d /net/rds/tcp_listen.c | |
| parent | devlink: fix trace format string (diff) | |
| download | kernel-qcow2-linux-a93d01f5777e99f24b5b3948e06673ada148337c.tar.gz kernel-qcow2-linux-a93d01f5777e99f24b5b3948e06673ada148337c.tar.xz kernel-qcow2-linux-a93d01f5777e99f24b5b3948e06673ada148337c.zip | |
RDS: TCP: avoid bad page reference in rds_tcp_listen_data_ready
As the existing comments in rds_tcp_listen_data_ready() indicate,
it is possible under some race-windows to get to this function with the
accept() socket. If that happens, we could run into a sequence whereby
thread 1 thread 2
rds_tcp_accept_one() thread
sets up new_sock via ->accept().
The sk_user_data is now
sock_def_readable
data comes in for new_sock,
->sk_data_ready is called, and
we land in rds_tcp_listen_data_ready
rds_tcp_set_callbacks()
takes the sk_callback_lock and
sets up sk_user_data to be the cp
read_lock sk_callback_lock
ready = cp
unlock sk_callback_lock
page fault on ready
In the above sequence, we end up with a panic on a bad page reference
when trying to execute (*ready)(). Instead we need to call
sock_def_readable() safely, which is what this patch achieves.
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/rds/tcp_listen.c')
| -rw-r--r-- | net/rds/tcp_listen.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/rds/tcp_listen.c b/net/rds/tcp_listen.c index ca975a217a49..73040e319e4b 100644 --- a/net/rds/tcp_listen.c +++ b/net/rds/tcp_listen.c @@ -183,6 +183,8 @@ void rds_tcp_listen_data_ready(struct sock *sk) */ if (sk->sk_state == TCP_LISTEN) rds_tcp_accept_work(sk); + else + ready = rds_tcp_listen_sock_def_readable(sock_net(sk)); out: read_unlock_bh(&sk->sk_callback_lock); |