From c686043b3a504208fb36ee935055c68ff210eac6 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Fri, 22 Nov 2019 23:47:02 +0100 Subject: allowedips: safely dereference rcu roots Signed-off-by: Jason A. Donenfeld --- src/allowedips.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/src/allowedips.c b/src/allowedips.c index 610aab0..72667d5 100644 --- a/src/allowedips.c +++ b/src/allowedips.c @@ -299,14 +299,18 @@ void wg_allowedips_free(struct allowedips *table, struct mutex *lock) RCU_INIT_POINTER(table->root4, NULL); RCU_INIT_POINTER(table->root6, NULL); if (rcu_access_pointer(old4)) { - root_remove_peer_lists(old4); - call_rcu(&rcu_dereference_protected(old4, - lockdep_is_held(lock))->rcu, root_free_rcu); + struct allowedips_node *node = rcu_dereference_protected(old4, + lockdep_is_held(lock)); + + root_remove_peer_lists(node); + call_rcu(&node->rcu, root_free_rcu); } if (rcu_access_pointer(old6)) { - root_remove_peer_lists(old6); - call_rcu(&rcu_dereference_protected(old6, - lockdep_is_held(lock))->rcu, root_free_rcu); + struct allowedips_node *node = rcu_dereference_protected(old6, + lockdep_is_held(lock)); + + root_remove_peer_lists(node); + call_rcu(&node->rcu, root_free_rcu); } } -- cgit v1.2.3-59-g8ed1b