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Date:   Mon, 21 Feb 2022 14:33:25 +0100
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To:     Jiri Pirko <jiri@nvidia.com>
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org
From:   Niels Dossche <niels.dossche@ugent.be>
Subject: [PATCH] devlink: use devlink lock on DEVLINK_CMD_PORT_SPLIT
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devlink_nl_cmd_port_split_doit is executed without taking the devlink
instance lock. This function calls to devlink_port_get_from_info, which
calls devlink_port_get_from_attrs, which calls
devlink_port_get_by_index, which accesses devlink->port_list without the
instance lock taken, while in other places devlink->port_list access
always happens with the instance lock taken. The documentation in the
struct also say that the devlink lock protects the port_list.

The flag for no locking was added after refactoring the code to no
longer use a global lock.

Fixes: 2406e7e546b2 ("devlink: Add per devlink instance lock")
Signed-off-by: Niels Dossche <niels.dossche@ugent.be>
---
 net/core/devlink.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/net/core/devlink.c b/net/core/devlink.c
index fcd9f6d85cf1..563becaa03a6 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -8645,7 +8645,6 @@ static const struct genl_small_ops devlink_nl_ops[] = {
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit = devlink_nl_cmd_port_split_doit,
 		.flags = GENL_ADMIN_PERM,
-		.internal_flags = DEVLINK_NL_FLAG_NO_LOCK,
 	},
 	{
 		.cmd = DEVLINK_CMD_PORT_UNSPLIT,
-- 
2.35.1