From: Eiichi Tsukata eiichi.tsukata@nutanix.com

stable inclusion from stable-v4.19.220 commit 913c24af2d13a3fd304462916ee98e298d56bdce category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9S23H CVE: CVE-2021-47538 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

--------------------------------

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.c... # v1 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Liu Chuang liuchuang40@huawei.com --- net/rxrpc/peer_object.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/net/rxrpc/peer_object.c b/net/rxrpc/peer_object.c index b91b090217cd..d0a1ebecc6fb 100644 --- a/net/rxrpc/peer_object.c +++ b/net/rxrpc/peer_object.c @@ -299,6 +299,12 @@ static struct rxrpc_peer *rxrpc_create_peer(struct rxrpc_sock *rx, 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(struct rxrpc_sock *rx, 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 rxrpc_peer *peer) 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_peer *peer) 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); } }