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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 C8DD3C433E0 for ; Mon, 29 Jun 2020 20:16:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9D54E20656 for ; Mon, 29 Jun 2020 20:16:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593461805; bh=cL38UWE7GwcD4GEHg4xYrfg67HEgIfAslckE1BzZB+U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=a76q4ZN2P8LcUdpHHKgsNHrOiaFK+4l08+a/bnVGCzoDcenGT0yIHdxw7TyvYot0K d6+DoeFZEiS0Z9DEkOxZdMc7IgDB7iNib8JtoDTztCuWk5YqfH0V00LUBq49+OHHFm 5iLyFsDGcd+rteG96y0TfNry+k4GTRQUMGkdHMTA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732813AbgF2UQo (ORCPT ); Mon, 29 Jun 2020 16:16:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:40570 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732810AbgF2TaQ (ORCPT ); Mon, 29 Jun 2020 15:30:16 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 15A732520B; Mon, 29 Jun 2020 15:35:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593444925; bh=cL38UWE7GwcD4GEHg4xYrfg67HEgIfAslckE1BzZB+U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DhUZRdsC6wVLdI7k8BQ2jRf3APLDEXYOFxxhBLGxECVoY27JPDW6IbZ/plT1WYE2/ Yr5z+hVCtQvysq52jU78J5opQy/k4Jbn/jJ+1BYq65ZhyS+3Y2Damr673/R7OL2oBI 1lGYr1ZLIXZBzRsuJPQv4FYTIw7oaIczMcf4ay+0= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Florian Westphal , syzbot+51471b4aae195285a4a3@syzkaller.appspotmail.com, Eric Dumazet , "David S . Miller" , Greg Kroah-Hartman Subject: [PATCH 4.19 022/131] net: use correct this_cpu primitive in dev_recursion_level Date: Mon, 29 Jun 2020 11:33:13 -0400 Message-Id: <20200629153502.2494656-23-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200629153502.2494656-1-sashal@kernel.org> References: <20200629153502.2494656-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.19.131-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-4.19.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 4.19.131-rc1 X-KernelTest-Deadline: 2020-07-01T15:34+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Florian Westphal commit 28b05b92886871bdd8e6a9df73e3a15845fe8ef4 upstream. syzbot reports: BUG: using __this_cpu_read() in preemptible code: caller is dev_recursion_level include/linux/netdevice.h:3052 [inline] __this_cpu_preempt_check+0x246/0x270 lib/smp_processor_id.c:47 dev_recursion_level include/linux/netdevice.h:3052 [inline] ip6_skb_dst_mtu include/net/ip6_route.h:245 [inline] I erronously downgraded a this_cpu_read to __this_cpu_read when moving dev_recursion_level() around. Reported-by: syzbot+51471b4aae195285a4a3@syzkaller.appspotmail.com Fixes: 97cdcf37b57e ("net: place xmit recursion in softnet data") Signed-off-by: Florian Westphal Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- include/linux/netdevice.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 41beebcc61f45..85dc3497c74f1 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3001,7 +3001,7 @@ DECLARE_PER_CPU_ALIGNED(struct softnet_data, softnet_data); static inline int dev_recursion_level(void) { - return __this_cpu_read(softnet_data.xmit.recursion); + return this_cpu_read(softnet_data.xmit.recursion); } #define XMIT_RECURSION_LIMIT 10 -- 2.25.1