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=-19.0 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 5A83AC433E6 for ; Mon, 29 Mar 2021 08:55:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4775461919 for ; Mon, 29 Mar 2021 08:55:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233294AbhC2Iyp (ORCPT ); Mon, 29 Mar 2021 04:54:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:54462 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233861AbhC2Ifx (ORCPT ); Mon, 29 Mar 2021 04:35:53 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id EB58D61959; Mon, 29 Mar 2021 08:35:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1617006933; bh=Y1pnNa4YSPpaegk5Uo+Sh9u3XXUR+H5QYQsYj6dEHfM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=powegfNK14UPs4nYLa+/5xuCj0pj+KfYoF1//9asQ+gSXEArMpPsRMSFJyHCpn5Vp QmbpfRTuY4Wv+RG9Ee70NjyRPqhLl8zQ8SqADfhfrfiYy1qr3rPAy0QmhVYFLSRtBI dj2YdZ9+68nHpx3G7KxxpllNQJL+et8akEuQfRxM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , Herbert Xu , syzbot , "David S. Miller" , Sasha Levin Subject: [PATCH 5.11 122/254] macvlan: macvlan_count_rx() needs to be aware of preemption Date: Mon, 29 Mar 2021 09:57:18 +0200 Message-Id: <20210329075637.235694006@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210329075633.135869143@linuxfoundation.org> References: <20210329075633.135869143@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: Eric Dumazet [ Upstream commit dd4fa1dae9f4847cc1fd78ca468ad69e16e5db3e ] macvlan_count_rx() can be called from process context, it is thus necessary to disable preemption before calling u64_stats_update_begin() syzbot was able to spot this on 32bit arch: WARNING: CPU: 1 PID: 4632 at include/linux/seqlock.h:271 __seqprop_assert include/linux/seqlock.h:271 [inline] WARNING: CPU: 1 PID: 4632 at include/linux/seqlock.h:271 __seqprop_assert.constprop.0+0xf0/0x11c include/linux/seqlock.h:269 Modules linked in: Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 4632 Comm: kworker/1:3 Not tainted 5.12.0-rc2-syzkaller #0 Hardware name: ARM-Versatile Express Workqueue: events macvlan_process_broadcast Backtrace: [<82740468>] (dump_backtrace) from [<827406dc>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:252) r7:00000080 r6:60000093 r5:00000000 r4:8422a3c4 [<827406c4>] (show_stack) from [<82751b58>] (__dump_stack lib/dump_stack.c:79 [inline]) [<827406c4>] (show_stack) from [<82751b58>] (dump_stack+0xb8/0xe8 lib/dump_stack.c:120) [<82751aa0>] (dump_stack) from [<82741270>] (panic+0x130/0x378 kernel/panic.c:231) r7:830209b4 r6:84069ea4 r5:00000000 r4:844350d0 [<82741140>] (panic) from [<80244924>] (__warn+0xb0/0x164 kernel/panic.c:605) r3:8404ec8c r2:00000000 r1:00000000 r0:830209b4 r7:0000010f [<80244874>] (__warn) from [<82741520>] (warn_slowpath_fmt+0x68/0xd4 kernel/panic.c:628) r7:81363f70 r6:0000010f r5:83018e50 r4:00000000 [<827414bc>] (warn_slowpath_fmt) from [<81363f70>] (__seqprop_assert include/linux/seqlock.h:271 [inline]) [<827414bc>] (warn_slowpath_fmt) from [<81363f70>] (__seqprop_assert.constprop.0+0xf0/0x11c include/linux/seqlock.h:269) r8:5a109000 r7:0000000f r6:a568dac0 r5:89802300 r4:00000001 [<81363e80>] (__seqprop_assert.constprop.0) from [<81364af0>] (u64_stats_update_begin include/linux/u64_stats_sync.h:128 [inline]) [<81363e80>] (__seqprop_assert.constprop.0) from [<81364af0>] (macvlan_count_rx include/linux/if_macvlan.h:47 [inline]) [<81363e80>] (__seqprop_assert.constprop.0) from [<81364af0>] (macvlan_broadcast+0x154/0x26c drivers/net/macvlan.c:291) r5:89802300 r4:8a927740 [<8136499c>] (macvlan_broadcast) from [<81365020>] (macvlan_process_broadcast+0x258/0x2d0 drivers/net/macvlan.c:317) r10:81364f78 r9:8a86d000 r8:8a9c7e7c r7:8413aa5c r6:00000000 r5:00000000 r4:89802840 [<81364dc8>] (macvlan_process_broadcast) from [<802696a4>] (process_one_work+0x2d4/0x998 kernel/workqueue.c:2275) r10:00000008 r9:8404ec98 r8:84367a02 r7:ddfe6400 r6:ddfe2d40 r5:898dac80 r4:8a86d43c [<802693d0>] (process_one_work) from [<80269dcc>] (worker_thread+0x64/0x54c kernel/workqueue.c:2421) r10:00000008 r9:8a9c6000 r8:84006d00 r7:ddfe2d78 r6:898dac94 r5:ddfe2d40 r4:898dac80 [<80269d68>] (worker_thread) from [<80271f40>] (kthread+0x184/0x1a4 kernel/kthread.c:292) r10:85247e64 r9:898dac80 r8:80269d68 r7:00000000 r6:8a9c6000 r5:89a2ee40 r4:8a97bd00 [<80271dbc>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:158) Exception stack(0x8a9c7fb0 to 0x8a9c7ff8) Fixes: 412ca1550cbe ("macvlan: Move broadcasts into a work queue") Signed-off-by: Eric Dumazet Cc: Herbert Xu Reported-by: syzbot Acked-by: Herbert Xu Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- include/linux/if_macvlan.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/linux/if_macvlan.h b/include/linux/if_macvlan.h index 96556c64c95d..10c94a3936ca 100644 --- a/include/linux/if_macvlan.h +++ b/include/linux/if_macvlan.h @@ -43,13 +43,14 @@ static inline void macvlan_count_rx(const struct macvlan_dev *vlan, if (likely(success)) { struct vlan_pcpu_stats *pcpu_stats; - pcpu_stats = this_cpu_ptr(vlan->pcpu_stats); + pcpu_stats = get_cpu_ptr(vlan->pcpu_stats); u64_stats_update_begin(&pcpu_stats->syncp); pcpu_stats->rx_packets++; pcpu_stats->rx_bytes += len; if (multicast) pcpu_stats->rx_multicast++; u64_stats_update_end(&pcpu_stats->syncp); + put_cpu_ptr(vlan->pcpu_stats); } else { this_cpu_inc(vlan->pcpu_stats->rx_errors); } -- 2.30.1