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 37C4A152E02 for ; Sun, 18 May 2025 03:46:10 +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=1747539971; cv=none; b=rfn0JCqS5Z/WrbatOctQGvn9zztkLDPe4gyzm5VhWo6/7vW8WbGv8qHNZ+veH+ALunOevf1m2Df3CJZ1Z82T/9dxvbBTnt/JnzwnMn1tjcyDjTtnYZpVtvIzcpKG5oxhclinO0LaBV/C04zx+QCGp5AD0xk5e9KU/PBTK2DCvpI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747539971; c=relaxed/simple; bh=aXvJKxmzfESpaedYEM0k3r230KTw/3k6G8+3Tse+Lhs=; h=From:To:Cc:Subject:Date:Message-Id; b=SiVZk8Jl4U0a8hgyb8zuMpuDHNk5ffHKATlhwQKAJb2px+UaHkY3U+ImklLlqMIlKjIQ3dMyTJ/wnevgwsXeuzuMcjosG2NW5u6ZVcHjUx1TkcZEdpONymkOGd6Sg7o6rXPfulpxEzefvV0LaYlfNuuF2A31/TDCVnykbeOxjT8= 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=YZVFu5hN; 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="YZVFu5hN" Received: by linux.microsoft.com (Postfix, from userid 1127) id B905D20277FE; Sat, 17 May 2025 20:46:09 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com B905D20277FE DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1747539969; bh=lPGYH1glaOFQwG0Qf4sdwd5qCLAWVCDmPlEySsWR4Kg=; h=From:To:Cc:Subject:Date:From; b=YZVFu5hNn5B/6ZcyI8N+lV4bZjBscpuGSM4OQXHe+7+xV9aOIuYhpp06pyvXANrmZ VitEc5x57JtQm06HuOapnJHzyXRcZ3VjNx1ZQdOc9nn7NFrN4fvEH6ZKGzk5YmnRrK VWe23r16gYElr1eOVBzSUq8G7kRKSRqW+eZdA/Ls= From: Saurabh Sengar To: ssengar@microsoft.com Cc: Saurabh Sengar , stable@vger.kernel.org Subject: [PATCH net] hv_netvsc: fix potential deadlock in netvsc_vf_setxdp() Date: Sat, 17 May 2025 20:46:07 -0700 Message-Id: <1747539967-10795-1-git-send-email-ssengar@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 Precedence: bulk X-Mailing-List: stable@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 this lock in noop in this case. Fix this by using netif_xdp_propagate instead of dev_xdp_propagate to avoid recursive locking in this path. This issue has not observed so far because net_shaper_ops was unset, making the lock path effectively a no-op. To prevent recursive locking and avoid this deadlock, replace dev_xdp_propagate() with netif_xdp_propagate(), which does not acquire the lock again. Also, clean up the unregistration path by removing 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 --- 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