net: airoha: Move ndesc initialization at end of airoha_qdma_init_rx_queue()

If queue entry or DMA descriptor list allocation fails in
airoha_qdma_init_rx_queue routine, airoha_qdma_cleanup() will trigger a
NULL pointer dereference running netif_napi_del() for RX queue NAPIs
since netif_napi_add() has never been executed to this particular RX NAPI.
The issue is due to the early ndesc initialization in
airoha_qdma_init_rx_queue() since airoha_qdma_cleanup() relies on ndesc
value to check if the queue is properly initialized. Fix the issue moving
ndesc initialization at end of airoha_qdma_init_tx routine.
Move page_pool allocation after descriptor list allocation in order to
avoid memory leaks if desc allocation fails.

Fixes: 23020f049327 ("net: airoha: Introduce ethernet support for EN7581 SoC")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20260420-airoha_qdma_init_rx_queue-fix-v2-1-d99347e5c18d@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c
index e17e40a2090d724f75a6b21a23707610fe131b14..ff948d555a7d3c683376cf91932f607a05c8025e 100644 (file)
--- a/drivers/net/ethernet/airoha/airoha_eth.c
+++ b/drivers/net/ethernet/airoha/airoha_eth.c
@@ -745,14 +745,18 @@ static int airoha_qdma_init_rx_queue(struct airoha_queue *q,
        dma_addr_t dma_addr;
 
        q->buf_size = PAGE_SIZE / 2;
-       q->ndesc = ndesc;
        q->qdma = qdma;
 
-       q->entry = devm_kzalloc(eth->dev, q->ndesc * sizeof(*q->entry),
+       q->entry = devm_kzalloc(eth->dev, ndesc * sizeof(*q->entry),
                                GFP_KERNEL);
        if (!q->entry)
                return -ENOMEM;
 
+       q->desc = dmam_alloc_coherent(eth->dev, ndesc * sizeof(*q->desc),
+                                     &dma_addr, GFP_KERNEL);
+       if (!q->desc)
+               return -ENOMEM;
+
        q->page_pool = page_pool_create(&pp_params);
        if (IS_ERR(q->page_pool)) {
                int err = PTR_ERR(q->page_pool);
@@ -761,11 +765,7 @@ static int airoha_qdma_init_rx_queue(struct airoha_queue *q,
                return err;
        }
 
-       q->desc = dmam_alloc_coherent(eth->dev, q->ndesc * sizeof(*q->desc),
-                                     &dma_addr, GFP_KERNEL);
-       if (!q->desc)
-               return -ENOMEM;
-
+       q->ndesc = ndesc;
        netif_napi_add(eth->napi_dev, &q->napi, airoha_qdma_rx_napi_poll);
 
        airoha_qdma_wr(qdma, REG_RX_RING_BASE(qid), dma_addr);