[PATCH 4.12 084/106] net/mlx5: Fix command completion after timeout access invalid structure

[Greg Kroah-Hartman]

4.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Moshe Shemesh <moshe@xxxxxxxxxxxx>


[ Upstream commit 061870800efb4e3d1ad4082a2569363629bdfcfc ]

Completion on timeout should not free the driver command entry structure
as it will need to access it again once real completion event from FW
will occur.

Fixes: 73dd3a4839c1 ('net/mlx5: Avoid using pending command interface slots')
Signed-off-by: Moshe Shemesh <moshe@xxxxxxxxxxxx>
Cc: kernel-team@xxxxxx
Signed-off-by: Saeed Mahameed <saeedm@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/mellanox/mlx5/core/cmd.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
@@ -955,7 +955,7 @@ static int mlx5_cmd_invoke(struct mlx5_c
 
 	err = wait_func(dev, ent);
 	if (err == -ETIMEDOUT)
-		goto out_free;
+		goto out;
 
 	ds = ent->ts2 - ent->ts1;
 	op = MLX5_GET(mbox_in, in->first.data, opcode);
@@ -1419,6 +1419,7 @@ void mlx5_cmd_comp_handler(struct mlx5_c
 					mlx5_core_err(dev, "Command completion arrived after timeout (entry idx = %d).\n",
 						      ent->idx);
 					free_ent(cmd, ent->idx);
+					free_cmd(ent);
 				}
 				continue;
 			}
@@ -1477,7 +1478,8 @@ void mlx5_cmd_comp_handler(struct mlx5_c
 				free_msg(dev, ent->in);
 
 				err = err ? err : ent->status;
-				free_cmd(ent);
+				if (!forced)
+					free_cmd(ent);
 				callback(err, context);
 			} else {
 				complete(&ent->done);