[PATCH] mlxsw: spectrum_router: Fix use after free

In mlxsw_sp_router_fib4_add_info_destroy(), the fib_entry pointer is used
after it has been freed by mlxsw_sp_fib_entry_destroy(). Use a temporary
variable to fix this.

Fixes: 61c503f976b5449e ("mlxsw: spectrum_router: Implement fib4 add/del switchdev obj ops")
Signed-off-by: Vincent Stehlé <redacted>
Cc: Jiri Pirko <redacted>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
index 81418d6..90bb93b 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c

@@ -1651,9 +1651,10 @@ static void mlxsw_sp_router_fib4_add_info_destroy(void const *data)
 	const struct mlxsw_sp_router_fib4_add_info *info = data;
 	struct mlxsw_sp_fib_entry *fib_entry = info->fib_entry;
 	struct mlxsw_sp *mlxsw_sp = info->mlxsw_sp;
+	struct mlxsw_sp_vr *vr = fib_entry->vr;
 
 	mlxsw_sp_fib_entry_destroy(fib_entry);
-	mlxsw_sp_vr_put(mlxsw_sp, fib_entry->vr);
+	mlxsw_sp_vr_put(mlxsw_sp, vr);
 	kfree(info);
 }
 

-- 
2.8.1

On Sun, Aug 14, 2016 at 03:38:29PM +0200, Vincent Stehlé wrote:

In mlxsw_sp_router_fib4_add_info_destroy(), the fib_entry pointer is used
after it has been freed by mlxsw_sp_fib_entry_destroy(). Use a temporary
variable to fix this.

Fixes: 61c503f976b5449e ("mlxsw: spectrum_router: Implement fib4 add/del switchdev obj ops")
Signed-off-by: Vincent Stehlé <redacted>
Cc: Jiri Pirko <redacted>

Acked-by: Ido Schimmel <redacted>

Thank you.

From: Vincent Stehlé <redacted>
Date: Sun, 14 Aug 2016 15:38:29 +0200

In mlxsw_sp_router_fib4_add_info_destroy(), the fib_entry pointer is used
after it has been freed by mlxsw_sp_fib_entry_destroy(). Use a temporary
variable to fix this.

Fixes: 61c503f976b5449e ("mlxsw: spectrum_router: Implement fib4 add/del switchdev obj ops")
Signed-off-by: Vincent Stehlé <redacted>
Cc: Jiri Pirko <redacted>

Applied.