FAILED: patch "[PATCH] net/mlx5: Fix potential sleeping in atomic context" failed to apply to 4.14-stable tree

FAILED: patch "[PATCH] net/mlx5: Fix potential sleeping in atomic context" failed to apply to 4.14-stable tree

[gregkh]

The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

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>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
index 9fe8e3c204d6..fe501ba88bea 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;
 }