[PATCH v2] net/mlx5: Fix use-after-free

From: Gustavo A. R. Silva
Date: Thu Mar 22 2018 - 14:45:03 EST


_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")
Reviewed-by: Yuval Shaia <yuval.shaia@xxxxxxxxxx>
Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
---
Changes in v2:
- Use a short subject prefix as suggested by Yuval Shaia.
- Add Yuval's Reviewed-by.

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