[PATCH] net/mlx4: Memcpy at slave_event should copy sizeof mlx4_eqe

From: Carol L Soto <redacted>

If the caps.eqe_size is bigger than the struct mlx4_eqe then there
is a potential for corrupting data at the master context. We can see
the message "Master failed to generate an EQE for slave: X" when the 
event_eqe array wraps and we can see potential oops at the function
mlx4_GEN_EQE. 

Signed-off-by: Carol L Soto <redacted>
---
 drivers/net/ethernet/mellanox/mlx4/eq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/eq.c b/drivers/net/ethernet/mellanox/mlx4/eq.c
index c344884..603d1c3 100644
--- a/drivers/net/ethernet/mellanox/mlx4/eq.c
+++ b/drivers/net/ethernet/mellanox/mlx4/eq.c

@@ -196,7 +196,7 @@ static void slave_event(struct mlx4_dev *dev, u8 slave, struct mlx4_eqe *eqe)
 		return;
 	}
 
-	memcpy(s_eqe, eqe, dev->caps.eqe_size - 1);
+	memcpy(s_eqe, eqe, sizeof(struct mlx4_eqe) - 1);
 	s_eqe->slave_id = slave;
 	/* ensure all information is written before setting the ownersip bit */
 	dma_wmb();

-- 
1.8.3.1

On Fri, Oct 23, 2015 at 4:19 PM,  [off-list ref] wrote:

From: Carol L Soto <redacted>

If the caps.eqe_size is bigger than the struct mlx4_eqe then there
is a potential for corrupting data at the master context. We can see
the message "Master failed to generate an EQE for slave: X" when the
event_eqe array wraps and we can see potential oops at the function
mlx4_GEN_EQE.

Signed-off-by: Carol L Soto <redacted>

Hi Carol,

Does this fixes a specific commit? if yes, please add a Fixes: line
before your signature, maybe
one the changes to enable CQE/EQE striding introduced that?

43c816c67a53 net/mlx4_core: Cache line EQE size support
77507aa249ae net/mlx4_core: Enable CQE/EQE stride support

I also added Yishai and Jack who should review your fix

Or.



Or.

Hi Carol,

Good catch!

Need to add an additional chunk to your fix -- see below.

On Sun, 25 Oct 2015 10:26:07 +0200
Or Gerlitz [off-list ref] wrote:

quoted

---
 drivers/net/ethernet/mellanox/mlx4/eq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/eq.c

b/drivers/net/ethernet/mellanox/mlx4/eq.c index c344884..603d1c3
100644 --- a/drivers/net/ethernet/mellanox/mlx4/eq.c

+++ b/drivers/net/ethernet/mellanox/mlx4/eq.c

@@ -196,7 +196,7 @@ static void slave_event(struct mlx4_dev *dev,

u8 slave, struct mlx4_eqe *eqe) return;
        }

-       memcpy(s_eqe, eqe, dev->caps.eqe_size - 1);
+       memcpy(s_eqe, eqe, sizeof(struct mlx4_eqe) - 1);
        s_eqe->slave_id = slave;
        /* ensure all information is written before setting the
ownersip bit */ dma_wmb();

diff --git a/drivers/net/ethernet/mellanox/mlx4/cmd.c b/drivers/net/ethernet/mellanox/mlx4/cmd.c
index 0a32020..2177e56 100644
--- a/drivers/net/ethernet/mellanox/mlx4/cmd.c
+++ b/drivers/net/ethernet/mellanox/mlx4/cmd.c

@@ -2398,7 +2398,7 @@ int mlx4_multi_func_init(struct mlx4_dev *dev)
 			}
 		}
 
-		memset(&priv->mfunc.master.cmd_eqe, 0, dev->caps.eqe_size);
+		memset(&priv->mfunc.master.cmd_eqe, 0, sizeof(struct mlx4_eqe));
 		priv->mfunc.master.cmd_eqe.type = MLX4_EVENT_TYPE_CMD;
 		INIT_WORK(&priv->mfunc.master.comm_work,
 			  mlx4_master_comm_channel);

quoted

--
1.8.3.1

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