[PATCH net-next v2 07/11] net: bridge: don't recurse on the port's netdev ops lock
From: Jakub Kicinski <kuba@kernel.org>
Date: 2026-06-03 01:28:57
Also in:
linux-leds
Subsystem:
ethernet bridge, networking [general], the rest · Maintainers:
Nikolay Aleksandrov, Ido Schimmel, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
port_cost() calls __ethtool_get_link_ksettings() on the port device, which will soon take the port's ops lock. br_port_carrier_check() is reached via the NETDEV_CHANGE notifier from linkwatch, which already holds the port's ops lock, so the call would deadlock. Make port_cost() expect the port's ops lock held and switch to netif_get_link_ksettings(). The only other caller is new_nbp(), make sure it takes the lock explicitly. Signed-off-by: Jakub Kicinski <kuba@kernel.org> --- net/bridge/br_if.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index d39571e13744..049d1d25bc26 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c@@ -19,6 +19,7 @@ #include <linux/if_ether.h> #include <linux/slab.h> #include <net/dsa.h> +#include <net/netdev_lock.h> #include <net/sock.h> #include <linux/if_vlan.h> #include <net/switchdev.h>
@@ -30,13 +31,13 @@ * Determine initial path cost based on speed. * using recommendations from 802.1d standard * - * Since driver might sleep need to not be holding any locks. + * Since driver might sleep, we need to not be holding any bridge spinlocks. */ static int port_cost(struct net_device *dev) { struct ethtool_link_ksettings ecmd; - if (!__ethtool_get_link_ksettings(dev, &ecmd)) { + if (!netif_get_link_ksettings(dev, &ecmd)) { switch (ecmd.base.speed) { case SPEED_10000: return 2;
@@ -436,7 +437,9 @@ static struct net_bridge_port *new_nbp(struct net_bridge *br, p->br = br; netdev_hold(dev, &p->dev_tracker, GFP_KERNEL); p->dev = dev; + netdev_lock_ops(dev); p->path_cost = port_cost(dev); + netdev_unlock_ops(dev); p->priority = 0x8000 >> BR_PORT_BITS; p->port_no = index; p->flags = BR_LEARNING | BR_FLOOD | BR_MCAST_FLOOD | BR_BCAST_FLOOD;
--
2.54.0