From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 5E55625C814; Wed, 21 May 2025 10:25:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747823109; cv=none; b=lW9HozleZIcCy1IaapBOVuQfRwJPYCphXcQRK13eY2+mTiAGTdf6XQ35vg6mxBPLgo0LFM+D+Ru1H4lXKfucOBfW8PFnzoRspdKMYR1rbFDf4j3XvaAFj8Mx4dKQXjDbo0A5SSzXENcWc0zDdyi16yx+am+0I8GSZ/8TQJ9gozw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747823109; c=relaxed/simple; bh=5HlH8MNJv3syXIN/vHnN2vVQp8Ri0Bh049wtA3tHBCE=; h=From:To:Cc:Subject:Date:Message-Id; b=F1jFZlYmdjy/1hQJTJuTKU0si8mkmh+UabbGCCZsu+SDqdO5uKMgUZAaziTniLc8dG+bEYfl+4OOcpy12+dK2514KTrUfo3JunB3K7S+/r08oW3eK9JeGX4Adu0goKfKVLU2FJ6+4zTyDmKZHc3hLxXPN1MQ2vZbjpiqp3NrEaY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=eWeJQa6e; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="eWeJQa6e" Received: by linux.microsoft.com (Postfix, from userid 1127) id C8E8C206832E; Wed, 21 May 2025 03:25:06 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com C8E8C206832E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1747823106; bh=QR4U2caREfe4Ci0S/IeCgwAGch4AUN3kUS6ReAl1HII=; h=From:To:Cc:Subject:Date:From; b=eWeJQa6ex5RvTfbojYleEB1LCyZwvno5vXiEyXQi32dqUJu2w3hOass/vOFcuQ845 byn7nsXClFZKcu9Me+QeA2wBWBk9sjRvBlwpzz5Pp1mgHqtjYRwPBH5J5TQ/WhIjFl gnoMDBCZt1cafttyeupHhDqUm91PSgNEJ3DLnBSQ= From: Saurabh Sengar To: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, horms@kernel.org, ast@kernel.org, daniel@iogearbox.net, hawk@kernel.org, john.fastabend@gmail.com, sdf@fomichev.me, kuniyu@amazon.com, ahmed.zaki@intel.com, aleksander.lobakin@intel.com, linux-hyperv@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org Cc: ssengar@microsoft.com, stable@vger.kernel.org, Saurabh Sengar Subject: [PATCH net,v2] hv_netvsc: fix potential deadlock in netvsc_vf_setxdp() Date: Wed, 21 May 2025 03:25:03 -0700 Message-Id: <1747823103-3420-1-git-send-email-ssengar@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The MANA driver's probe registers netdevice via the following call chain: mana_probe() register_netdev() register_netdevice() register_netdevice() calls notifier callback for netvsc driver, holding the netdev mutex via netdev_lock_ops(). Further this netvsc notifier callback end up attempting to acquire the same lock again in dev_xdp_propagate() leading to deadlock. netvsc_netdev_event() netvsc_vf_setxdp() dev_xdp_propagate() This deadlock was not observed so far because net_shaper_ops was never set, and thus the lock was effectively a no-op in this case. Fix this by using netif_xdp_propagate() instead of dev_xdp_propagate() to avoid recursive locking in this path. Also, clean up the unregistration path by removing the unnecessary call to netvsc_vf_setxdp(), since unregister_netdevice_many_notify() already performs this cleanup via dev_xdp_uninstall(). Fixes: 97246d6d21c2 ("net: hold netdev instance lock during ndo_bpf") Cc: stable@vger.kernel.org Signed-off-by: Saurabh Sengar Tested-by: Erni Sri Satya Vennela Reviewed-by: Haiyang Zhang --- [V2] - Modified commit message drivers/net/hyperv/netvsc_bpf.c | 2 +- drivers/net/hyperv/netvsc_drv.c | 2 -- net/core/dev.c | 1 + 3 files changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/net/hyperv/netvsc_bpf.c b/drivers/net/hyperv/netvsc_bpf.c index e01c5997a551..1dd3755d9e6d 100644 --- a/drivers/net/hyperv/netvsc_bpf.c +++ b/drivers/net/hyperv/netvsc_bpf.c @@ -183,7 +183,7 @@ int netvsc_vf_setxdp(struct net_device *vf_netdev, struct bpf_prog *prog) xdp.command = XDP_SETUP_PROG; xdp.prog = prog; - ret = dev_xdp_propagate(vf_netdev, &xdp); + ret = netif_xdp_propagate(vf_netdev, &xdp); if (ret && prog) bpf_prog_put(prog); diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index d8b169ac0343..ee3aaf9c10e6 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -2462,8 +2462,6 @@ static int netvsc_unregister_vf(struct net_device *vf_netdev) netdev_info(ndev, "VF unregistering: %s\n", vf_netdev->name); - netvsc_vf_setxdp(vf_netdev, NULL); - reinit_completion(&net_device_ctx->vf_add); netdev_rx_handler_unregister(vf_netdev); netdev_upper_dev_unlink(vf_netdev, ndev); diff --git a/net/core/dev.c b/net/core/dev.c index fccf2167b235..8c6c9d7fba26 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -9953,6 +9953,7 @@ int netif_xdp_propagate(struct net_device *dev, struct netdev_bpf *bpf) return dev->netdev_ops->ndo_bpf(dev, bpf); } +EXPORT_SYMBOL_GPL(netif_xdp_propagate); u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode) { -- 2.43.0