net: mvpp2: fix the txq_init error path

When an allocation in the txq_init path fails, the allocated buffers
end-up being freed twice: in the txq_init error path, and in txq_deinit.
This lead to issues as txq_deinit would work on already freed memory
regions:

    kernel BUG at mm/slub.c:3915!
    Internal error: Oops - BUG: 0 [#1] PREEMPT SMP

This patch fixes this by removing the txq_init own error path, as the
txq_deinit function is always called on errors. This was introduced by
TSO as way more buffers are allocated.

Fixes: 186cd4d4e414 ("net: mvpp2: software tso support")
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 18 deletions

diff --git a/drivers/net/ethernet/marvell/mvpp2.c b/drivers/net/ethernet/marvell/mvpp2.c
index 6c20e811f973..79f01cd80dd7 100644
--- a/drivers/net/ethernet/marvell/mvpp2.c
+++ b/drivers/net/ethernet/marvell/mvpp2.c
@@ -5805,7 +5805,7 @@ static int mvpp2_txq_init(struct mvpp2_port *port,
                                                 sizeof(*txq_pcpu->buffs),
                                                 GFP_KERNEL);
                 if (!txq_pcpu->buffs)
-                        goto cleanup;
+                        return -ENOMEM;
 
                 txq_pcpu->count = 0;
                 txq_pcpu->reserved_num = 0;
@@ -5821,26 +5821,10 @@ static int mvpp2_txq_init(struct mvpp2_port *port,
                                            &txq_pcpu->tso_headers_dma,
                                            GFP_KERNEL);
                 if (!txq_pcpu->tso_headers)
-                        goto cleanup;
+                        return -ENOMEM;
         }
 
         return 0;
-cleanup:
-        for_each_present_cpu(cpu) {
-                txq_pcpu = per_cpu_ptr(txq->pcpu, cpu);
-                kfree(txq_pcpu->buffs);
-
-                dma_free_coherent(port->dev->dev.parent,
-                                  txq_pcpu->size * TSO_HEADER_SIZE,
-                                  txq_pcpu->tso_headers,
-                                  txq_pcpu->tso_headers_dma);
-        }
-
-        dma_free_coherent(port->dev->dev.parent,
-                          txq->size * MVPP2_DESC_ALIGNED_SIZE,
-                          txq->descs, txq->descs_dma);
-
-        return -ENOMEM;
 }
 
 /* Free allocated TXQ resources */