[PATCH net-next] devlink: Use after free in devlink_health_reporter_destroy()

[Dan Carpenter]

This calls kfree(reporter); before dereferencing reporter on the next
line when it does mutex_unlock(&reporter->devlink->lock);

Fixes: 880ee82f0313 ("devlink: Add health reporter create/destroy 
functionality")
Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com>
---
 net/core/devlink.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/core/devlink.c b/net/core/devlink.c
index 60248a53c0ad..deccce13285a 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -4223,14 +4223,16 @@ EXPORT_SYMBOL_GPL(devlink_health_reporter_create);
 void
 devlink_health_reporter_destroy(struct devlink_health_reporter *reporter)
 {
-       mutex_lock(&reporter->devlink->lock);
+       struct devlink *devlink = reporter->devlink;
+
+       mutex_lock(&devlink->lock);
        list_del(&reporter->list);
        devlink_health_buffers_destroy(reporter->dump_buffers_array,
                                       
DEVLINK_HEALTH_SIZE_TO_BUFFERS(reporter->ops->dump_size));
        devlink_health_buffers_destroy(reporter->diagnose_buffers_array,
                                       
DEVLINK_HEALTH_SIZE_TO_BUFFERS(reporter->ops->diagnose_size));
        kfree(reporter);
-       mutex_unlock(&reporter->devlink->lock);
+       mutex_unlock(&devlink->lock);
 }
 EXPORT_SYMBOL_GPL(devlink_health_reporter_destroy);
 
-- 
2.17.1