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From:   Sasha Levin <Alexander.Levin@microsoft.com>
To:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "stable@vger.kernel.org" <stable@vger.kernel.org>
CC:     Antoine Tenart <antoine.tenart@free-electrons.com>,
        "David S . Miller" <davem@davemloft.net>,
        Sasha Levin <Alexander.Levin@microsoft.com>
Subject: [PATCH AUTOSEL for 4.14 065/100] net: mvpp2: fix the txq_init error
 path
Thread-Topic: [PATCH AUTOSEL for 4.14 065/100] net: mvpp2: fix the txq_init
 error path
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Date:   Wed, 24 Jan 2018 04:14:58 +0000
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From: Antoine Tenart <antoine.tenart@free-electrons.com>

[ Upstream commit ba2d8d887d962c2f790e6dc01b2fd25b4608720b ]

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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
 drivers/net/ethernet/marvell/mvpp2.c | 20 ++------------------
 1 file changed, 2 insertions(+), 18 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvpp2.c b/drivers/net/ethernet/ma=
rvell/mvpp2.c
index fcf9ba5eb8d1..8044cfb0b667 100644
--- a/drivers/net/ethernet/marvell/mvpp2.c
+++ b/drivers/net/ethernet/marvell/mvpp2.c
@@ -5606,7 +5606,7 @@ static int mvpp2_txq_init(struct mvpp2_port *port,
 						sizeof(*txq_pcpu->buffs),
 						GFP_KERNEL);
 		if (!txq_pcpu->buffs)
-			goto cleanup;
+			return -ENOMEM;
=20
 		txq_pcpu->count =3D 0;
 		txq_pcpu->reserved_num =3D 0;
@@ -5619,26 +5619,10 @@ 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;
 	}
=20
 	return 0;
-cleanup:
-	for_each_present_cpu(cpu) {
-		txq_pcpu =3D 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;
 }
=20
 /* Free allocated TXQ resources */
--=20
2.11.0