[PATCH 5.15 125/207] rxrpc: Fix rxrpc_local leak in rxrpc_lookup_peer()

Greg Kroah-Hartman
2021-12-06T15:53:11Z

From: Eiichi Tsukata <eiichi.tsukata@nutanix.com>

commit beacff50edbd6c9659a6f15fc7f6126909fade29 upstream.

Need to call rxrpc_put_local() for peer candidate before kfree() as it
holds a ref to rxrpc_local.

[DH: v2: Changed to abstract the peer freeing code out into a function]

Fixes: 9ebeddef58c4 ("rxrpc: rxrpc_peer needs to hold a ref on the rxrpc_local record")
Signed-off-by: Eiichi Tsukata <eiichi.tsukata@nutanix.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/all/20211121041608.133740-2-eiichi.tsukata@nutanix.com/ # v1
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/rxrpc/peer_object.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)

--- a/net/rxrpc/peer_object.c
+++ b/net/rxrpc/peer_object.c
@@ -299,6 +299,12 @@ static struct rxrpc_peer *rxrpc_create_p
return peer;
}

+static void rxrpc_free_peer(struct rxrpc_peer *peer)
+{
+ rxrpc_put_local(peer->local);
+ kfree_rcu(peer, rcu);
+}
+
/*
* Set up a new incoming peer. There shouldn't be any other matching peers
* since we've already done a search in the list from the non-reentrant context
@@ -365,7 +371,7 @@ struct rxrpc_peer *rxrpc_lookup_peer(str
spin_unlock_bh(&rxnet->peer_hash_lock);

if (peer)
- kfree(candidate);
+ rxrpc_free_peer(candidate);
else
peer = candidate;
}
@@ -420,8 +426,7 @@ static void __rxrpc_put_peer(struct rxrp
list_del_init(&peer->keepalive_link);
spin_unlock_bh(&rxnet->peer_hash_lock);

- rxrpc_put_local(peer->local);
- kfree_rcu(peer, rcu);
+ rxrpc_free_peer(peer);
}

/*
@@ -457,8 +462,7 @@ void rxrpc_put_peer_locked(struct rxrpc_
if (n == 0) {
hash_del_rcu(&peer->hash_link);
list_del_init(&peer->keepalive_link);
- rxrpc_put_local(peer->local);
- kfree_rcu(peer, rcu);
+ rxrpc_free_peer(peer);
}
}