From: Oliver Hartkopp Date: Fri, 18 Jun 2021 17:36:45 +0000 (+0200) Subject: can: gw: synchronize rcu operations before removing gw job entry X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=2c9e095989b4779767bca0a532f168e80ed09ec7;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git can: gw: synchronize rcu operations before removing gw job entry 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 Signed-off-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/can/gw.c b/net/can/gw.c index 5114b8f07fd4..4db0b1819890 100644 --- a/net/can/gw.c +++ b/net/can/gw.c @@ -494,6 +494,7 @@ static int cgw_notifier(struct notifier_block *nb, 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 net *net) 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 *skb, struct nlmsghdr *nlh, hlist_del(&gwj->list); cgw_unregister_filter(net, gwj); + synchronize_rcu(); kmem_cache_free(cgw_cache, gwj); err = 0; break;