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authorFaicker Mo <faicker.mo@gmail.com>2026-05-11 17:05:51 +0300
committerJakub Kicinski <kuba@kernel.org>2026-05-14 05:01:03 +0300
commitb84c5632c7b31f8910167075a8128cfb9e50fcfe (patch)
tree93f8348aed93e8d2921a14468aeed5b511d6eb33
parent9a390d34d55cb4ecbca4981c660dd95440827c70 (diff)
downloadlinux-b84c5632c7b31f8910167075a8128cfb9e50fcfe.tar.xz
net: net_failover: Fix the deadlock in slave register
There is netdev_lock_ops() before the NETDEV_REGISTER notifier in register_netdevice(), so use the non-locking functions in net_failover_slave_register(). failover_slave_register() in failover_existing_slave_register() adds lock and unlock ops too. Call Trace: <TASK> __schedule+0x30d/0x7a0 schedule+0x27/0x90 schedule_preempt_disabled+0x15/0x30 __mutex_lock.constprop.0+0x538/0x9e0 __mutex_lock_slowpath+0x13/0x20 mutex_lock+0x3b/0x50 dev_set_mtu+0x40/0xe0 net_failover_slave_register+0x24/0x280 failover_slave_register+0x103/0x1b0 failover_event+0x15e/0x210 ? dropmon_net_event+0xac/0xe0 notifier_call_chain+0x5e/0xe0 raw_notifier_call_chain+0x16/0x30 call_netdevice_notifiers_info+0x52/0xa0 register_netdevice+0x5f4/0x7c0 register_netdev+0x1e/0x40 _mlx5e_probe+0xe2/0x370 [mlx5_core] mlx5e_probe+0x59/0x70 [mlx5_core] ? __pfx_mlx5e_probe+0x10/0x10 [mlx5_core] Fixes: 4c975fd70002 ("net: hold instance lock during NETDEV_REGISTER/UP") Signed-off-by: Faicker Mo <faicker.mo@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-rw-r--r--drivers/net/net_failover.c12
-rw-r--r--net/core/failover.c6
2 files changed, 11 insertions, 7 deletions
diff --git a/drivers/net/net_failover.c b/drivers/net/net_failover.c
index d0361aaf25ef..3f7d31033bae 100644
--- a/drivers/net/net_failover.c
+++ b/drivers/net/net_failover.c
@@ -502,7 +502,7 @@ static int net_failover_slave_register(struct net_device *slave_dev,
/* Align MTU of slave with failover dev */
orig_mtu = slave_dev->mtu;
- err = dev_set_mtu(slave_dev, failover_dev->mtu);
+ err = netif_set_mtu(slave_dev, failover_dev->mtu);
if (err) {
netdev_err(failover_dev, "unable to change mtu of %s to %u register failed\n",
slave_dev->name, failover_dev->mtu);
@@ -512,11 +512,11 @@ static int net_failover_slave_register(struct net_device *slave_dev,
dev_hold(slave_dev);
if (netif_running(failover_dev)) {
- err = dev_open(slave_dev, NULL);
+ err = netif_open(slave_dev, NULL);
if (err && (err != -EBUSY)) {
netdev_err(failover_dev, "Opening slave %s failed err:%d\n",
slave_dev->name, err);
- goto err_dev_open;
+ goto err_netif_open;
}
}
@@ -562,10 +562,10 @@ static int net_failover_slave_register(struct net_device *slave_dev,
err_vlan_add:
dev_uc_unsync(slave_dev, failover_dev);
dev_mc_unsync(slave_dev, failover_dev);
- dev_close(slave_dev);
-err_dev_open:
+ netif_close(slave_dev);
+err_netif_open:
dev_put(slave_dev);
- dev_set_mtu(slave_dev, orig_mtu);
+ netif_set_mtu(slave_dev, orig_mtu);
done:
return err;
}
diff --git a/net/core/failover.c b/net/core/failover.c
index 11bb183c7a1b..e43c59cd6868 100644
--- a/net/core/failover.c
+++ b/net/core/failover.c
@@ -12,6 +12,7 @@
#include <uapi/linux/if_arp.h>
#include <linux/rtnetlink.h>
#include <linux/if_vlan.h>
+#include <net/netdev_lock.h>
#include <net/failover.h>
static LIST_HEAD(failover_list);
@@ -221,8 +222,11 @@ failover_existing_slave_register(struct net_device *failover_dev)
for_each_netdev(net, dev) {
if (netif_is_failover(dev))
continue;
- if (ether_addr_equal(failover_dev->perm_addr, dev->perm_addr))
+ if (ether_addr_equal(failover_dev->perm_addr, dev->perm_addr)) {
+ netdev_lock_ops(dev);
failover_slave_register(dev);
+ netdev_unlock_ops(dev);
+ }
}
rtnl_unlock();
}