From: Oliver Hartkopp socketcan@hartkopp.net
commit fb8696ab14adadb2e3f6c17c18ed26b3ecd96691 upstream.
can_can_gw_rcv() is called under RCU protection, so after calling can_rx_unregister(), we have to call synchronize_rcu in order to wait for any RCU read-side critical sections to finish before removing the kmem_cache entry with the referenced gw job entry.
Link: https://lore.kernel.org/r/20210618173645.2238-1-socketcan@hartkopp.net Fixes: c1aabdf379bc ("can-gw: add netlink based CAN routing") Cc: linux-stable stable@vger.kernel.org Signed-off-by: Oliver Hartkopp socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- net/can/gw.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/net/can/gw.c +++ b/net/can/gw.c @@ -494,6 +494,7 @@ static int cgw_notifier(struct notifier_ if (gwj->src.dev == dev || gwj->dst.dev == dev) { hlist_del(&gwj->list); cgw_unregister_filter(net, gwj); + synchronize_rcu(); kmem_cache_free(cgw_cache, gwj); } } @@ -941,6 +942,7 @@ static void cgw_remove_all_jobs(struct n hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) { hlist_del(&gwj->list); cgw_unregister_filter(net, gwj); + synchronize_rcu(); kmem_cache_free(cgw_cache, gwj); } } @@ -1010,6 +1012,7 @@ static int cgw_remove_job(struct sk_buff
hlist_del(&gwj->list); cgw_unregister_filter(net, gwj); + synchronize_rcu(); kmem_cache_free(cgw_cache, gwj); err = 0; break;