[PATCH 4.19 081/338] crypto: ccp - ccp_dmaengine_unregister release dma channels

[Greg Kroah-Hartman]

From: Dāvis Mosāns <davispuh@xxxxxxxxx>

[ Upstream commit 54cce8ecb9254f971b40a72911c6da403720a2d2 ]

ccp_dmaengine_register adds dma_chan->device_node to dma_dev->channels list
but ccp_dmaengine_unregister didn't remove them.
That can cause crashes in various dmaengine methods that tries to use dma_dev->channels

Fixes: 58ea8abf4904 ("crypto: ccp - Register the CCP as a DMA...")
Signed-off-by: Dāvis Mosāns <davispuh@xxxxxxxxx>
Acked-by: John Allen <john.allen@xxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/crypto/ccp/ccp-dmaengine.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/crypto/ccp/ccp-dmaengine.c b/drivers/crypto/ccp/ccp-dmaengine.c
index a83588d6ba72..8209273eb85b 100644
--- a/drivers/crypto/ccp/ccp-dmaengine.c
+++ b/drivers/crypto/ccp/ccp-dmaengine.c
@@ -631,6 +631,20 @@ static int ccp_terminate_all(struct dma_chan *dma_chan)
 	return 0;
 }
 
+static void ccp_dma_release(struct ccp_device *ccp)
+{
+	struct ccp_dma_chan *chan;
+	struct dma_chan *dma_chan;
+	unsigned int i;
+
+	for (i = 0; i < ccp->cmd_q_count; i++) {
+		chan = ccp->ccp_dma_chan + i;
+		dma_chan = &chan->dma_chan;
+		tasklet_kill(&chan->cleanup_tasklet);
+		list_del_rcu(&dma_chan->device_node);
+	}
+}
+
 int ccp_dmaengine_register(struct ccp_device *ccp)
 {
 	struct ccp_dma_chan *chan;
@@ -732,6 +746,7 @@ int ccp_dmaengine_register(struct ccp_device *ccp)
 	return 0;
 
 err_reg:
+	ccp_dma_release(ccp);
 	kmem_cache_destroy(ccp->dma_desc_cache);
 
 err_cache:
@@ -745,6 +760,7 @@ void ccp_dmaengine_unregister(struct ccp_device *ccp)
 	struct dma_device *dma_dev = &ccp->dma_dev;
 
 	dma_async_device_unregister(dma_dev);
+	ccp_dma_release(ccp);
 
 	kmem_cache_destroy(ccp->dma_desc_cache);
 	kmem_cache_destroy(ccp->dma_cmd_cache);
-- 
2.34.1