[PATCH v3 1/2] scsi: elx: efct: free the RQ buffers already allocated when one fails

efct_hw_rx_buffer_alloc() allocates an array of descriptors and then a
coherent DMA buffer for each entry. When one of those allocations fails it
frees the array and returns NULL, leaving every buffer allocated before it
mapped:

	if (!prq->dma.virt) {
		efc_log_err(hw->os, "DMA allocation failed\n");
		kfree(rq_buf);
		return NULL;
	}

The caller only sees NULL and the array that held the addresses is gone,
so nothing can free them afterwards. efct_hw_rx_free() cannot help either,
it walks rq->hdr_buf and rq->payload_buf, which are only assigned once this
function succeeds.

Use efct_hw_rx_buffer_free() for the entries that were filled in. It
unmaps those buffers and frees the array, and it is defined below
efct_hw_rx_buffer_alloc(), so add a forward declaration.

Fixes: 580c0255e4ef ("scsi: elx: efct: RQ buffer, memory pool allocation and deallocation APIs")
Signed-off-by: Ali Ahmet Memis <[email protected]>
---
 drivers/scsi/elx/efct/efct_hw.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/elx/efct/efct_hw.c b/drivers/scsi/elx/efct/efct_hw.c
index b79c6a7ea791..cc600220168a 100644
--- a/drivers/scsi/elx/efct/efct_hw.c
+++ b/drivers/scsi/elx/efct/efct_hw.c
@@ -1170,6 +1170,10 @@ efct_get_wwpn(struct efct_hw *hw)
 	return get_unaligned_be64(p);
 }
 
+static void
+efct_hw_rx_buffer_free(struct efct_hw *hw, struct efc_hw_rq_buffer *rq_buf,
+		       u32 count);
+
 static struct efc_hw_rq_buffer *
 efct_hw_rx_buffer_alloc(struct efct_hw *hw, u32 rqindex, u32 count,
 			u32 size)
@@ -1196,7 +1200,7 @@ efct_hw_rx_buffer_alloc(struct efct_hw *hw, u32 rqindex, u32 count,
 						   GFP_KERNEL);
 		if (!prq->dma.virt) {
 			efc_log_err(hw->os, "DMA allocation failed\n");
-			kfree(rq_buf);
+			efct_hw_rx_buffer_free(hw, rq_buf, i);
 			return NULL;
 		}
 	}
-- 
2.55.0