diff mbox series

[net-next,3/3] devlink: Protect rate list with lock while switching modes

Message ID 1624455795-5160-4-git-send-email-dlinkin@nvidia.com (mailing list archive)
State Accepted
Commit a3e5e5797faad0db319d106afaa31b9020fac44f
Delegated to: Netdev Maintainers
Headers show
Series Fixes for devlink rate objects API | expand

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netdev/source_inline success Was 0 now: 0
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netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 1 this patch: 1
netdev/kdoc success Errors and warnings before: 0 this patch: 0
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netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 15 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 1 this patch: 1
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Commit Message

Dmytro Linkin June 23, 2021, 1:43 p.m. UTC 
From: Dmytro Linkin <dlinkin@nvidia.com>

Devlink eswitch set command doesn't hold devlink->lock, which makes
possible race condition between rate list traversing and others devlink
rate KAPI calls, like devlink_rate_nodes_destroy().
Hold devlink lock while traversing the list.

Fixes: a8ecb93ef03d ("devlink: Introduce rate nodes")
Signed-off-by: Dmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
---
 net/core/devlink.c | 4 ++++
 1 file changed, 4 insertions(+)
diff mbox series

Patch

diff --git a/net/core/devlink.c b/net/core/devlink.c
index 153d432..8fdd04f 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -2710,11 +2710,15 @@  static int devlink_rate_nodes_check(struct devlink *devlink, u16 mode,
 {
 	struct devlink_rate *devlink_rate;
 
+	/* Take the lock to sync with devlink_rate_nodes_destroy() */
+	mutex_lock(&devlink->lock);
 	list_for_each_entry(devlink_rate, &devlink->rate_list, list)
 		if (devlink_rate_is_node(devlink_rate)) {
+			mutex_unlock(&devlink->lock);
 			NL_SET_ERR_MSG_MOD(extack, "Rate node(s) exists.");
 			return -EBUSY;
 		}
+	mutex_unlock(&devlink->lock);
 	return 0;
 }