rpmsg: glink: Don't send pending rx_done during remove

Attempting to transmit rx_done messages after the GLINK instance is
being torn down will cause use after free and memory leaks. So cancel
the intent_work and free up the pending intents.

With this there are no concurrent accessors of the channel left during
qcom_glink_native_remove() and there is therefor no need to hold the
spinlock during this operation - which would prohibit the use of
cancel_work_sync() in the release function. So remove this.

Fixes: 1d2ea36eead9 ("rpmsg: glink: Add rx done command")
Cc: stable@vger.kernel.org
Acked-by: Chris Lew <clew@codeaurora.org>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

diff --git a/drivers/rpmsg/qcom_glink_native.c b/drivers/rpmsg/qcom_glink_native.c
index 89e02ba..38599ff 100644 (file)
--- a/drivers/rpmsg/qcom_glink_native.c
+++ b/drivers/rpmsg/qcom_glink_native.c
@@ -241,11 +241,23 @@ static void qcom_glink_channel_release(struct kref *ref)
 {
        struct glink_channel *channel = container_of(ref, struct glink_channel,
                                                     refcount);
+       struct glink_core_rx_intent *intent;
        struct glink_core_rx_intent *tmp;
        unsigned long flags;
        int iid;
 
+       /* cancel pending rx_done work */
+       cancel_work_sync(&channel->intent_work);
+
        spin_lock_irqsave(&channel->intent_lock, flags);
+       /* Free all non-reuse intents pending rx_done work */
+       list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
+               if (!intent->reuse) {
+                       kfree(intent->data);
+                       kfree(intent);
+               }
+       }
+
        idr_for_each_entry(&channel->liids, tmp, iid) {
                kfree(tmp->data);
                kfree(tmp);
@@ -1625,7 +1637,6 @@ void qcom_glink_native_remove(struct qcom_glink *glink)
        struct glink_channel *channel;
        int cid;
        int ret;
-       unsigned long flags;
 
        disable_irq(glink->irq);
        cancel_work_sync(&glink->rx_work);
@@ -1634,7 +1645,6 @@ void qcom_glink_native_remove(struct qcom_glink *glink)
        if (ret)
                dev_warn(glink->dev, "Can't remove GLINK devices: %d\n", ret);
 
-       spin_lock_irqsave(&glink->idr_lock, flags);
        /* Release any defunct local channels, waiting for close-ack */
        idr_for_each_entry(&glink->lcids, channel, cid)
                kref_put(&channel->refcount, qcom_glink_channel_release);
@@ -1645,7 +1655,6 @@ void qcom_glink_native_remove(struct qcom_glink *glink)
 
        idr_destroy(&glink->lcids);
        idr_destroy(&glink->rcids);
-       spin_unlock_irqrestore(&glink->idr_lock, flags);
        mbox_free_channel(glink->mbox_chan);
 }
 EXPORT_SYMBOL_GPL(qcom_glink_native_remove);