From: Wentao_Liang <Wentao_Liang_g@163.com>
Date: Thu, 19 Aug 2021 22:30:05 +0800
Subject: net/mlx5: DR, fix a potential use-after-free bug
Patch-mainline: v5.15-rc1
Git-commit: 6cc64770fb386b10a64a1fe09328396de7bb5262
References: jsc#SLE-19253 stable-5.14.6

In line 849 (#1), "mlx5dr_htbl_put(cur_htbl);" drops the reference to
cur_htbl and may cause cur_htbl to be freed.

However, cur_htbl is subsequently used in the next line, which may result
in an use-after-free bug.

Fix this by calling mlx5dr_err() before the cur_htbl is put.

Signed-off-by: Wentao_Liang <Wentao_Liang_g@163.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlx5/core/steering/dr_rule.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_rule.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/steering/dr_rule.c
@@ -862,9 +862,9 @@ again:
 			new_htbl = dr_rule_rehash(rule, nic_rule, cur_htbl,
 						  ste_location, send_ste_list);
 			if (!new_htbl) {
-				mlx5dr_htbl_put(cur_htbl);
 				mlx5dr_err(dmn, "Failed creating rehash table, htbl-log_size: %d\n",
 					   cur_htbl->chunk_size);
+				mlx5dr_htbl_put(cur_htbl);
 			} else {
 				cur_htbl = new_htbl;
 			}