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Message-ID: <20250327135659.2057487-2-sdf@fomichev.me>
Date: Thu, 27 Mar 2025 06:56:49 -0700
From: Stanislav Fomichev <sdf@...ichev.me>
To: netdev@...r.kernel.org
Cc: davem@...emloft.net,
edumazet@...gle.com,
kuba@...nel.org,
pabeni@...hat.com,
Cosmin Ratiu <cratiu@...dia.com>
Subject: [PATCH net v2 01/11] net: switch to netif_disable_lro in inetdev_init
Cosmin reports the following deadlock:
dump_stack_lvl+0x62/0x90
print_deadlock_bug+0x274/0x3b0
__lock_acquire+0x1229/0x2470
lock_acquire+0xb7/0x2b0
__mutex_lock+0xa6/0xd20
dev_disable_lro+0x20/0x80
inetdev_init+0x12f/0x1f0
inetdev_event+0x48b/0x870
notifier_call_chain+0x38/0xf0
netif_change_net_namespace+0x72e/0x9f0
do_setlink.isra.0+0xd5/0x1220
rtnl_newlink+0x7ea/0xb50
rtnetlink_rcv_msg+0x459/0x5e0
netlink_rcv_skb+0x54/0x100
netlink_unicast+0x193/0x270
netlink_sendmsg+0x204/0x450
Switch to netif_disable_lro which assumes the caller holds the instance
lock. inetdev_init is called for blackhole device (which sw device and
doesn't grab instance lock) and from REGISTER/UNREGISTER notifiers.
We already hold the instance lock for REGISTER notifier during
netns change and we'll soon hold the lock during other paths.
Reported-by: Cosmin Ratiu <cratiu@...dia.com>
Fixes: ad7c7b2172c3 ("net: hold netdev instance lock during sysfs operations")
Signed-off-by: Stanislav Fomichev <sdf@...ichev.me>
---
net/core/dev.c | 1 +
net/ipv4/devinet.c | 2 +-
2 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/core/dev.c b/net/core/dev.c
index be17e0660144..80523f75ee6b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1771,6 +1771,7 @@ void netif_disable_lro(struct net_device *dev)
netdev_unlock_ops(lower_dev);
}
}
+EXPORT_SYMBOL(netif_disable_lro);
/**
* dev_disable_gro_hw - disable HW Generic Receive Offload on a device
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 754f60fb6e25..77e5705ac799 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -281,7 +281,7 @@ static struct in_device *inetdev_init(struct net_device *dev)
if (!in_dev->arp_parms)
goto out_kfree;
if (IPV4_DEVCONF(in_dev->cnf, FORWARDING))
- dev_disable_lro(dev);
+ netif_disable_lro(dev);
/* Reference in_dev->dev */
netdev_hold(dev, &in_dev->dev_tracker, GFP_KERNEL);
/* Account for reference dev->ip_ptr (below) */
--
2.48.1
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