Commit 44138344 authored by Bart Van Assche's avatar Bart Van Assche Committed by Doug Ledford

IB/srpt: Rework srpt_disconnect_ch_sync()

This patch fixes a use-after-free issue for ch->release_done when
running the SRP protocol on top of the rdma_rxe driver.
Signed-off-by: default avatarBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
parent 795bc112
......@@ -1841,6 +1841,23 @@ static int srpt_disconnect_ch(struct srpt_rdma_ch *ch)
return ret;
}
static bool srpt_ch_closed(struct srpt_device *sdev, struct srpt_rdma_ch *ch)
{
struct srpt_rdma_ch *ch2;
bool res = true;
rcu_read_lock();
list_for_each_entry(ch2, &sdev->rch_list, list) {
if (ch2 == ch) {
res = false;
break;
}
}
rcu_read_unlock();
return res;
}
/*
* Send DREQ and wait for DREP. Return true if and only if this function
* changed the state of @ch.
......@@ -1848,31 +1865,24 @@ static int srpt_disconnect_ch(struct srpt_rdma_ch *ch)
static bool srpt_disconnect_ch_sync(struct srpt_rdma_ch *ch)
__must_hold(&sdev->mutex)
{
DECLARE_COMPLETION_ONSTACK(release_done);
struct srpt_device *sdev = ch->sport->sdev;
bool wait;
int ret;
lockdep_assert_held(&sdev->mutex);
pr_debug("ch %s-%d state %d\n", ch->sess_name, ch->qp->qp_num,
ch->state);
WARN_ON(ch->release_done);
ch->release_done = &release_done;
wait = !list_empty(&ch->list);
srpt_disconnect_ch(ch);
ret = srpt_disconnect_ch(ch);
mutex_unlock(&sdev->mutex);
if (!wait)
goto out;
while (wait_for_completion_timeout(&release_done, 180 * HZ) == 0)
while (wait_event_timeout(sdev->ch_releaseQ, srpt_ch_closed(sdev, ch),
5 * HZ) == 0)
pr_info("%s(%s-%d state %d): still waiting ...\n", __func__,
ch->sess_name, ch->qp->qp_num, ch->state);
out:
mutex_lock(&sdev->mutex);
return wait;
return ret == 0;
}
static void srpt_set_enabled(struct srpt_port *sport, bool enabled)
......@@ -1916,8 +1926,7 @@ static void srpt_release_channel_work(struct work_struct *w)
struct se_session *se_sess;
ch = container_of(w, struct srpt_rdma_ch, release_work);
pr_debug("%s: %s-%d; release_done = %p\n", __func__, ch->sess_name,
ch->qp->qp_num, ch->release_done);
pr_debug("%s-%d\n", ch->sess_name, ch->qp->qp_num);
sdev = ch->sport->sdev;
BUG_ON(!sdev);
......@@ -1946,14 +1955,6 @@ static void srpt_release_channel_work(struct work_struct *w)
mutex_lock(&sdev->mutex);
list_del_rcu(&ch->list);
if (ch->release_done)
complete(ch->release_done);
mutex_unlock(&sdev->mutex);
synchronize_rcu();
mutex_lock(&sdev->mutex);
INIT_LIST_HEAD(&ch->list);
mutex_unlock(&sdev->mutex);
wake_up(&sdev->ch_releaseQ);
......
......@@ -270,7 +270,6 @@ enum rdma_ch_state {
* @sess_name: Session name.
* @ini_guid: Initiator port GUID.
* @release_work: Allows scheduling of srpt_release_channel().
* @release_done: Enables waiting for srpt_release_channel() completion.
*/
struct srpt_rdma_ch {
struct ib_cm_id *cm_id;
......@@ -299,7 +298,6 @@ struct srpt_rdma_ch {
u8 sess_name[36];
u8 ini_guid[24];
struct work_struct release_work;
struct completion *release_done;
};
/**
......
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