4.19-stable review patch. If anyone has any objections, please let me know.
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From: Johannes Berg johannes.berg@intel.com
[ Upstream commit 3ba359c0cd6eb5ea772125a7aededb4a2d516684 ]
RCU use in bond_should_notify_peers() looks wrong, since it does rcu_dereference(), leaves the critical section, and uses the pointer after that.
Luckily, it's called either inside a nested RCU critical section or with the RTNL held.
Annotate it with rcu_dereference_rtnl() instead, and remove the inner RCU critical section.
Fixes: 4cb4f97b7e36 ("bonding: rebuild the lock use for bond_mii_monitor()") Reviewed-by: Jiri Pirko jiri@nvidia.com Signed-off-by: Johannes Berg johannes.berg@intel.com Acked-by: Jay Vosburgh jv@jvosburgh.net Link: https://patch.msgid.link/20240719094119.35c62455087d.I68eb9c0f02545b364b79a5... Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/bonding/bond_main.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 79b36f1c50aec..f0c0da85ba4fc 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -774,13 +774,10 @@ static struct slave *bond_find_best_slave(struct bonding *bond) return bestslave; }
+/* must be called in RCU critical section or with RTNL held */ static bool bond_should_notify_peers(struct bonding *bond) { - struct slave *slave; - - rcu_read_lock(); - slave = rcu_dereference(bond->curr_active_slave); - rcu_read_unlock(); + struct slave *slave = rcu_dereference_rtnl(bond->curr_active_slave);
if (!slave || !bond->send_peer_notif || !netif_carrier_ok(bond->dev) ||