From 06477f7ef8c103a71d2e8a251681242f1846bd19 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Thu, 6 Dec 2018 19:14:34 +0000 Subject: [PATCH] UPSTREAM: vhost/vsock: fix reset orphans race with close timeout [ Upstream commit c38f57da428b033f2721b611d84b1f40bde674a8 ] If a local process has closed a connected socket and hasn't received a RST packet yet, then the socket remains in the table until a timeout expires. When a vhost_vsock instance is released with the timeout still pending, the socket is never freed because vhost_vsock has already set the SOCK_DONE flag. Check if the close timer is pending and let it close the socket. This prevents the race which can leak sockets. Reported-by: Maximilian Riemensberger Cc: Graham Whaley Signed-off-by: Stefan Hajnoczi Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin (cherry picked from commit 06ec6679fe12cacafce68ab7b509586482a2ae1b) Bug: 121166534 Test: Ran cuttlefish with android-4.4 + vsock adb tunnel Signed-off-by: Cody Schuffelen Change-Id: I6b4564aebecc3938b789e56499a3f9b8bbbeb2a1 --- drivers/vhost/vsock.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index 744ee3a17768..72e914de473e 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -561,13 +561,21 @@ static void vhost_vsock_reset_orphans(struct sock *sk) * executing. */ - if (!vhost_vsock_get(vsk->remote_addr.svm_cid)) { - sock_set_flag(sk, SOCK_DONE); - vsk->peer_shutdown = SHUTDOWN_MASK; - sk->sk_state = SS_UNCONNECTED; - sk->sk_err = ECONNRESET; - sk->sk_error_report(sk); - } + /* If the peer is still valid, no need to reset connection */ + if (vhost_vsock_get(vsk->remote_addr.svm_cid)) + return; + + /* If the close timeout is pending, let it expire. This avoids races + * with the timeout callback. + */ + if (vsk->close_work_scheduled) + return; + + sock_set_flag(sk, SOCK_DONE); + vsk->peer_shutdown = SHUTDOWN_MASK; + sk->sk_state = SS_UNCONNECTED; + sk->sk_err = ECONNRESET; + sk->sk_error_report(sk); } static int vhost_vsock_dev_release(struct inode *inode, struct file *file)