From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EA3AEC433ED for ; Mon, 10 May 2021 12:50:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AEBB0610F8 for ; Mon, 10 May 2021 12:50:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348900AbhEJMrn (ORCPT ); Mon, 10 May 2021 08:47:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:49920 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233618AbhEJLOA (ORCPT ); Mon, 10 May 2021 07:14:00 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 28A9E61364; Mon, 10 May 2021 11:10:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620645036; bh=HYPQr5De+BztxcVMQkTJ1B1kSN3YQXCcudGHqQcosso=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=i4lKYZMhXX2R5vGzunDwZFZOSZAsZUdRipKAk+pEWVuIgaeZLlKZ2HNwBCO74EeyL wf/m8TjMV3hL4o5IVkZc7nVIpT7hYzZkQRgRIea4WoygA1xDol4RUMojf4GEKF2qyV hbAcYOnsu1/s8TD0MEF/XJH1DX5iRgARwQqRUqLE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ignat Korchagin , "David S. Miller" Subject: [PATCH 5.12 325/384] sfc: adjust efx->xdp_tx_queue_count with the real number of initialized queues Date: Mon, 10 May 2021 12:21:54 +0200 Message-Id: <20210510102025.510535787@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210510102014.849075526@linuxfoundation.org> References: <20210510102014.849075526@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ignat Korchagin commit 99ba0ea616aabdc8e26259fd722503e012199a76 upstream. efx->xdp_tx_queue_count is initially initialized to num_possible_cpus() and is later used to allocate and traverse efx->xdp_tx_queues lookup array. However, we may end up not initializing all the array slots with real queues during probing. This results, for example, in a NULL pointer dereference, when running "# ethtool -S ", similar to below [2570283.664955][T4126959] BUG: kernel NULL pointer dereference, address: 00000000000000f8 [2570283.681283][T4126959] #PF: supervisor read access in kernel mode [2570283.695678][T4126959] #PF: error_code(0x0000) - not-present page [2570283.710013][T4126959] PGD 0 P4D 0 [2570283.721649][T4126959] Oops: 0000 [#1] SMP PTI [2570283.734108][T4126959] CPU: 23 PID: 4126959 Comm: ethtool Tainted: G O 5.10.20-cloudflare-2021.3.1 #1 [2570283.752641][T4126959] Hardware name: [2570283.781408][T4126959] RIP: 0010:efx_ethtool_get_stats+0x2ca/0x330 [sfc] [2570283.796073][T4126959] Code: 00 85 c0 74 39 48 8b 95 a8 0f 00 00 48 85 d2 74 2d 31 c0 eb 07 48 8b 95 a8 0f 00 00 48 63 c8 49 83 c4 08 83 c0 01 48 8b 14 ca <48> 8b 92 f8 00 00 00 49 89 54 24 f8 39 85 a0 0f 00 00 77 d7 48 8b [2570283.831259][T4126959] RSP: 0018:ffffb79a77657ce8 EFLAGS: 00010202 [2570283.845121][T4126959] RAX: 0000000000000019 RBX: ffffb799cd0c9280 RCX: 0000000000000018 [2570283.860872][T4126959] RDX: 0000000000000000 RSI: ffff96dd970ce000 RDI: 0000000000000005 [2570283.876525][T4126959] RBP: ffff96dd86f0a000 R08: ffff96dd970ce480 R09: 000000000000005f [2570283.892014][T4126959] R10: ffffb799cd0c9fff R11: ffffb799cd0c9000 R12: ffffb799cd0c94f8 [2570283.907406][T4126959] R13: ffffffffc11b1090 R14: ffff96dd970ce000 R15: ffffffffc11cd66c [2570283.922705][T4126959] FS: 00007fa7723f8740(0000) GS:ffff96f51fac0000(0000) knlGS:0000000000000000 [2570283.938848][T4126959] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [2570283.952524][T4126959] CR2: 00000000000000f8 CR3: 0000001a73e6e006 CR4: 00000000007706e0 [2570283.967529][T4126959] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [2570283.982400][T4126959] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [2570283.997308][T4126959] PKRU: 55555554 [2570284.007649][T4126959] Call Trace: [2570284.017598][T4126959] dev_ethtool+0x1832/0x2830 Fix this by adjusting efx->xdp_tx_queue_count after probing to reflect the true value of initialized slots in efx->xdp_tx_queues. Signed-off-by: Ignat Korchagin Fixes: e26ca4b53582 ("sfc: reduce the number of requested xdp ev queues") Cc: # 5.12.x Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/sfc/efx_channels.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/net/ethernet/sfc/efx_channels.c +++ b/drivers/net/ethernet/sfc/efx_channels.c @@ -914,6 +914,8 @@ int efx_set_channels(struct efx_nic *efx } } } + if (xdp_queue_number) + efx->xdp_tx_queue_count = xdp_queue_number; rc = netif_set_real_num_tx_queues(efx->net_dev, efx->n_tx_channels); if (rc)