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From: Jakub Kicinski <kuba@kernel•org>
To: Kuniyuki Iwashima <kuniyu@amazon•com>
Cc: <andrew+netdev@lunn•ch>, <davem@davemloft•net>,
	<edumazet@google•com>, <horms@kernel•org>,
	<hramamurthy@google•com>, <jdamato@fastly•com>,
	<netdev@vger•kernel.org>, <pabeni@redhat•com>, <sdf@fomichev•me>
Subject: Re: [PATCH net-next v2 6/8] netdev: depend on netdev->lock for xdp features
Date: Thu, 10 Apr 2025 19:10:28 -0700	[thread overview]
Message-ID: <20250410191028.31a0eaf2@kernel.org> (raw)
In-Reply-To: <20250410171019.62128-1-kuniyu@amazon.com>

On Thu, 10 Apr 2025 10:10:01 -0700 Kuniyuki Iwashima wrote:
> syzkaller reported splats in register_netdevice() and
> unregister_netdevice_many_notify().
> 
> In register_netdevice(), some devices cannot use
> netdev_assert_locked().
> 
> In unregister_netdevice_many_notify(), maybe we need to
> hold ops lock in UNREGISTER as you initially suggested.
> Now do_setlink() deadlock does not happen.

Ah...  Thank you.

Do you have a reference to use as Reported-by, or its from a
non-public instance ?

I'll test this shortly:

diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index b64c614a00c4..891e2f60922f 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -38,7 +38,8 @@ netdev_nl_dev_fill(struct net_device *netdev, struct sk_buff *rsp,
        u64 xdp_rx_meta = 0;
        void *hdr;
 
-       netdev_assert_locked(netdev); /* note: rtnl_lock may not be held! */
+       /* note: rtnl_lock may or may not be held! */
+       netdev_assert_locked_or_invisible(netdev);
 
        hdr = genlmsg_iput(rsp, info);
        if (!hdr)
@@ -966,7 +967,9 @@ static int netdev_genl_netdevice_event(struct notifier_block *nb,
                netdev_genl_dev_notify(netdev, NETDEV_CMD_DEV_ADD_NTF);
                break;
        case NETDEV_UNREGISTER:
+               netdev_lock(netdev);
                netdev_genl_dev_notify(netdev, NETDEV_CMD_DEV_DEL_NTF);
+               netdev_unlock(netdev);
                break;
        case NETDEV_XDP_FEAT_CHANGE:
                netdev_genl_dev_notify(netdev, NETDEV_CMD_DEV_CHANGE_NTF);

  reply	other threads:[~2025-04-11  2:10 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-04-08 19:59 [PATCH net-next v2 0/8] net: depend on instance lock for queue related netlink ops Jakub Kicinski
2025-04-08 19:59 ` [PATCH net-next v2 1/8] net: avoid potential race between netdev_get_by_index_lock() and netns switch Jakub Kicinski
2025-04-08 19:59 ` [PATCH net-next v2 2/8] net: designate XSK pool pointers in queues as "ops protected" Jakub Kicinski
2025-04-08 19:59 ` [PATCH net-next v2 3/8] netdev: add "ops compat locking" helpers Jakub Kicinski
2025-04-08 19:59 ` [PATCH net-next v2 4/8] netdev: don't hold rtnl_lock over nl queue info get when possible Jakub Kicinski
2025-04-08 19:59 ` [PATCH net-next v2 5/8] xdp: double protect netdev->xdp_flags with netdev->lock Jakub Kicinski
2025-04-08 22:15   ` Harshitha Ramamurthy
2025-04-09 18:40   ` Martin KaFai Lau
2025-04-08 19:59 ` [PATCH net-next v2 6/8] netdev: depend on netdev->lock for xdp features Jakub Kicinski
2025-04-10 17:10   ` Kuniyuki Iwashima
2025-04-11  2:10     ` Jakub Kicinski [this message]
2025-04-11  2:23       ` Jakub Kicinski
2025-04-11 17:41         ` Stanislav Fomichev
2025-04-11 19:19           ` Jakub Kicinski
2025-04-11  2:36       ` Kuniyuki Iwashima
2025-04-08 19:59 ` [PATCH net-next v2 7/8] docs: netdev: break down the instance locking info per ops struct Jakub Kicinski
2025-04-09  2:59   ` Joe Damato
2025-04-10  6:01   ` Jacob Keller
2025-04-10 16:08     ` Jakub Kicinski
2025-04-10 22:35       ` Keller, Jacob E
2025-04-10 23:39         ` Jakub Kicinski
2025-04-11 21:26           ` Jacob Keller
2025-04-08 19:59 ` [PATCH net-next v2 8/8] netdev: depend on netdev->lock for qstats in ops locked drivers Jakub Kicinski
2025-04-10  5:23   ` Jacob Keller
2025-04-10 23:46     ` Jakub Kicinski
2025-04-11 21:29       ` Jacob Keller
2025-04-10  0:40 ` [PATCH net-next v2 0/8] net: depend on instance lock for queue related netlink ops patchwork-bot+netdevbpf

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