From ee27e330a953595903979ffdb84926843595a9fe Mon Sep 17 00:00:00 2001
From: Maor Gottlieb <maorg@nvidia.com>
Date: Wed, 1 Sep 2021 11:48:13 +0300
Subject: [PATCH] net/mlx5: Fix potential sleeping in atomic context
Fixes the below flow of sleeping in atomic context by releasing
the RCU lock before calling to free_match_list.
build_match_list() <- disables preempt
-> free_match_list()
-> tree_put_node()
-> down_write_ref_node() <- take write lock
Fixes: 693c6883bbc4 ("net/mlx5: Add hash table for flow groups in flow table")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
---
drivers/net/ethernet/mellanox/mlx5/core/fs_core.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
index 9fe8e3c204d63..fe501ba88bea9 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
@@ -1682,14 +1682,13 @@ static int build_match_list(struct match_list *match_head,
curr_match = kmalloc(sizeof(*curr_match), GFP_ATOMIC);
if (!curr_match) {
+ rcu_read_unlock();
free_match_list(match_head, ft_locked);
- err = -ENOMEM;
- goto out;
+ return -ENOMEM;
}
curr_match->g = g;
list_add_tail(&curr_match->list, &match_head->list);
}
-out:
rcu_read_unlock();
return err;
}
--
2.30.2