From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 19B0E51032 for ; Thu, 30 Nov 2023 14:34:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="bNO/XZY/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A39AC433C7; Thu, 30 Nov 2023 14:34:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1701354865; bh=klNdWVqUFRx1rdko1GgnHkABn04ulKqQQ4ULVHwq4H4=; h=Subject:To:Cc:From:Date:From; b=bNO/XZY/yAuQ1enVuet1V13JZe0UamQvLIRdQAlgxeFdSfBOLFt1W+7TvqgNFaSlq jVStr/OHHVjqaPQbK8ddfy1TypXPlcyDhn7/N/R79oNeht7o2tu2rSN8HeUf5UWdfZ YAXgw2q+5xNwEnYwUM8gySuzVbyqxUM/08jrWeXE= Subject: FAILED: patch "[PATCH] hv_netvsc: fix race of netvsc and VF register_netdevice" failed to apply to 5.4-stable tree To: haiyangz@microsoft.com,decui@microsoft.com,horms@kernel.org,pabeni@redhat.com,wojciech.drewek@intel.com Cc: From: Date: Thu, 30 Nov 2023 14:34:19 +0000 Message-ID: <2023113019-tray-spool-bb95@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x d30fb712e52964f2cf9a9c14cf67078394044837 # git commit -s git send-email --to '' --in-reply-to '2023113019-tray-spool-bb95@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: d30fb712e529 ("hv_netvsc: fix race of netvsc and VF register_netdevice") 351e1581395f ("hv_netvsc: Add XDP support") 0efeea5fb153 ("hv_netvsc: Add the support of hibernation") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From d30fb712e52964f2cf9a9c14cf67078394044837 Mon Sep 17 00:00:00 2001 From: Haiyang Zhang Date: Sun, 19 Nov 2023 08:23:41 -0800 Subject: [PATCH] hv_netvsc: fix race of netvsc and VF register_netdevice The rtnl lock also needs to be held before rndis_filter_device_add() which advertises nvsp_2_vsc_capability / sriov bit, and triggers VF NIC offering and registering. If VF NIC finished register_netdev() earlier it may cause name based config failure. To fix this issue, move the call to rtnl_lock() before rndis_filter_device_add(), so VF will be registered later than netvsc / synthetic NIC, and gets a name numbered (ethX) after netvsc. Cc: stable@vger.kernel.org Fixes: e04e7a7bbd4b ("hv_netvsc: Fix a deadlock by getting rtnl lock earlier in netvsc_probe()") Reported-by: Dexuan Cui Signed-off-by: Haiyang Zhang Reviewed-by: Wojciech Drewek Reviewed-by: Simon Horman Reviewed-by: Dexuan Cui Signed-off-by: Paolo Abeni diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index 3ba3c8fb28a5..5e528a76f5f5 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -2531,15 +2531,6 @@ static int netvsc_probe(struct hv_device *dev, goto devinfo_failed; } - nvdev = rndis_filter_device_add(dev, device_info); - if (IS_ERR(nvdev)) { - ret = PTR_ERR(nvdev); - netdev_err(net, "unable to add netvsc device (ret %d)\n", ret); - goto rndis_failed; - } - - eth_hw_addr_set(net, device_info->mac_adr); - /* We must get rtnl lock before scheduling nvdev->subchan_work, * otherwise netvsc_subchan_work() can get rtnl lock first and wait * all subchannels to show up, but that may not happen because @@ -2547,9 +2538,23 @@ static int netvsc_probe(struct hv_device *dev, * -> ... -> device_add() -> ... -> __device_attach() can't get * the device lock, so all the subchannels can't be processed -- * finally netvsc_subchan_work() hangs forever. + * + * The rtnl lock also needs to be held before rndis_filter_device_add() + * which advertises nvsp_2_vsc_capability / sriov bit, and triggers + * VF NIC offering and registering. If VF NIC finished register_netdev() + * earlier it may cause name based config failure. */ rtnl_lock(); + nvdev = rndis_filter_device_add(dev, device_info); + if (IS_ERR(nvdev)) { + ret = PTR_ERR(nvdev); + netdev_err(net, "unable to add netvsc device (ret %d)\n", ret); + goto rndis_failed; + } + + eth_hw_addr_set(net, device_info->mac_adr); + if (nvdev->num_chn > 1) schedule_work(&nvdev->subchan_work); @@ -2586,9 +2591,9 @@ static int netvsc_probe(struct hv_device *dev, return 0; register_failed: - rtnl_unlock(); rndis_filter_device_remove(dev, nvdev); rndis_failed: + rtnl_unlock(); netvsc_devinfo_put(device_info); devinfo_failed: free_percpu(net_device_ctx->vf_stats);