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Date:   Thu, 22 Mar 2018 13:03:42 -0500
From:   "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To:     Ilan Tayari <ilant@mellanox.com>,
        Boris Pismenny <borisp@mellanox.com>,
        Saeed Mahameed <saeedm@mellanox.com>,
        Matan Barak <matanb@mellanox.com>,
        Leon Romanovsky <leon@kernel.org>
Cc:     netdev@vger.kernel.org, linux-rdma@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Subject: [PATCH] net/mlx5/core/fpga/ipsec: Fix use-after-free
Message-ID: <20180322180342.GA18505@embeddedgus>
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_rule_ is being freed and then dereferenced by accessing rule->ctx

Fix this by copying the value returned by PTR_ERR(rule->ctx) into a local
variable for its safe use after freeing _rule_

Addresses-Coverity-ID: 1466041 ("Read from pointer after free")
Fixes: 05564d0ae075 ("net/mlx5: Add flow-steering commands for FPGA IPSec implementation")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/fpga/ipsec.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fpga/ipsec.c b/drivers/net/ethernet/mellanox/mlx5/core/fpga/ipsec.c
index 4f15685..0f5da49 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/fpga/ipsec.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/fpga/ipsec.c
@@ -1061,8 +1061,9 @@ static int fpga_ipsec_fs_create_fte(struct mlx5_core_dev *dev,
 
 	rule->ctx = mlx5_fpga_ipsec_fs_create_sa_ctx(dev, fte, is_egress);
 	if (IS_ERR(rule->ctx)) {
+		int err = PTR_ERR(rule->ctx);
 		kfree(rule);
-		return PTR_ERR(rule->ctx);
+		return err;
 	}
 
 	rule->fte = fte;
-- 
2.7.4