[PATCH 5.14 481/849] net: enetc: unmap DMA in enetc_send_cmd()

Greg Kroah-Hartman
2021-11-15T23:06:10Z

From: Tim Gardner <tim.gardner@canonical.com>

[ Upstream commit cd4bc63de774eee95e9bac26a565cd80e0fca421 ]

Coverity complains of a possible dereference of a null return value.

5. returned_null: kzalloc returns NULL. [show details]
6. var_assigned: Assigning: si_data = NULL return value from kzalloc.
488 si_data = kzalloc(data_size, __GFP_DMA | GFP_KERNEL);
489 cbd.length = cpu_to_le16(data_size);
490
491 dma = dma_map_single(&priv->si->pdev->dev, si_data,
492 data_size, DMA_FROM_DEVICE);

While this kzalloc() is unlikely to fail, I did notice that the function
returned without unmapping si_data.

Fix this by refactoring the error paths and checking for kzalloc()
failure.

Fixes: 888ae5a3952ba ("net: enetc: add tc flower psfp offload driver")
Cc: Claudiu Manoil <claudiu.manoil@nxp.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org (open list)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../net/ethernet/freescale/enetc/enetc_qos.c | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/freescale/enetc/enetc_qos.c b/drivers/net/ethernet/freescale/enetc/enetc_qos.c
index 4577226d3c6ad..0536d2c76fbc4 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_qos.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_qos.c
@@ -486,14 +486,16 @@ static int enetc_streamid_hw_set(struct enetc_ndev_priv *priv,

data_size = sizeof(struct streamid_data);
si_data = kzalloc(data_size, __GFP_DMA | GFP_KERNEL);
+ if (!si_data)
+ return -ENOMEM;
cbd.length = cpu_to_le16(data_size);

dma = dma_map_single(&priv->si->pdev->dev, si_data,
data_size, DMA_FROM_DEVICE);
if (dma_mapping_error(&priv->si->pdev->dev, dma)) {
netdev_err(priv->si->ndev, "DMA mapping failed!\n");
- kfree(si_data);
- return -ENOMEM;
+ err = -ENOMEM;
+ goto out;
}

cbd.addr[0] = cpu_to_le32(lower_32_bits(dma));
@@ -512,12 +514,10 @@ static int enetc_streamid_hw_set(struct enetc_ndev_priv *priv,

err = enetc_send_cmd(priv->si, &cbd);
if (err)
- return -EINVAL;
+ goto out;

- if (!enable) {
- kfree(si_data);
- return 0;
- }
+ if (!enable)
+ goto out;

/* Enable the entry overwrite again incase space flushed by hardware */
memset(&cbd, 0, sizeof(cbd));
@@ -560,6 +560,10 @@ static int enetc_streamid_hw_set(struct enetc_ndev_priv *priv,
}

err = enetc_send_cmd(priv->si, &cbd);
+out:
+ if (!dma_mapping_error(&priv->si->pdev->dev, dma))
+ dma_unmap_single(&priv->si->pdev->dev, dma, data_size, DMA_FROM_DEVICE);
+
kfree(si_data);

return err;
--
2.33.0