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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 63A37C4167B for ; Sun, 26 Nov 2023 09:46:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229539AbjKZJqt (ORCPT ); Sun, 26 Nov 2023 04:46:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39870 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229437AbjKZJqq (ORCPT ); Sun, 26 Nov 2023 04:46:46 -0500 Received: from mail-pf1-f198.google.com (mail-pf1-f198.google.com [209.85.210.198]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8D0BE85 for ; Sun, 26 Nov 2023 01:46:49 -0800 (PST) Received: by mail-pf1-f198.google.com with SMTP id d2e1a72fcca58-6cd8b5b2d04so143842b3a.0 for ; Sun, 26 Nov 2023 01:46:49 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1700992007; x=1701596807; h=to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=S2jxZKeNVhy8r3m++ysP7foF2GDOTArTqfIO8UDHyTk=; b=wZ/Hi0+B6GZ/0gpiRSnZGkBDfWH/pZBX4l6bUg8NJ8sNs5tITjI3yiRK9+CCIEGe47 iXcb9e20jb51BSjK5JX0nIwI9pSgKFJPbWoawXFYiGLuoYJD6879oM0QHxAR97jU8S7f yaYN8iGtbhqwevgQMplKRspF2TOM7xyag+tQwDK/BUzp4/MSon3wjgx/N0fyQFdkenYg En8DyoyJa7uYuna8nW1XqE/SVAtiSibaJlgCEEXXKFyv4ihJKffxdQj+4W8ekhqKxZtC s8YBnkMJoPc/BLPnX7O7bNXezZ0q5tidtiyXS9IDJ6h7tgUtlc4/4LsNHRaSvCdQLXbX 9GfA== X-Gm-Message-State: AOJu0YwYMaH3iBD48sEJ7xWthgZa44QjsBR7IlC6WQuOOBhMnJuDr/oe 4G0hsJTZR6BQn73ATKwpHP06HuZkZ3A/E2Gg+YgWAkp3HNG0zkE= X-Google-Smtp-Source: AGHT+IFpFby8ZUy2E0VADv2tVM+v1t0uH1r1Z63IQL67unRfv5jl29xbfkYkJJiDWY5mWpz0RS02CfPHpjhjF+GaUaCmmV9PJ+Og MIME-Version: 1.0 X-Received: by 2002:a05:6a00:3a03:b0:6cd:810:3875 with SMTP id fj3-20020a056a003a0300b006cd08103875mr729811pfb.5.1700992007000; Sun, 26 Nov 2023 01:46:47 -0800 (PST) Date: Sun, 26 Nov 2023 01:46:46 -0800 In-Reply-To: <000000000000f2771905a46374fe@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <00000000000057dbf4060b0b10b6@google.com> Subject: Re: [syzbot] [net?] possible deadlock in sch_direct_xmit From: syzbot To: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org For archival purposes, forwarding an incoming command email to linux-kernel@vger.kernel.org. *** Subject: [net?] possible deadlock in sch_direct_xmit Author: eadavis@qq.com please test deadlock in sch_direct_xmit #syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 4195a4bc26ca..d9d39887a550 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -337,13 +337,16 @@ bool sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q, #endif if (likely(skb)) { - HARD_TX_LOCK(dev, txq, smp_processor_id()); - if (!netif_xmit_frozen_or_stopped(txq)) + if (!netif_xmit_frozen_or_stopped(txq)) { + HARD_TX_LOCK(dev, txq, smp_processor_id()); + netif_tx_stop_queue(txq); skb = dev_hard_start_xmit(skb, dev, txq, &ret); + netif_tx_start_queue(txq); + HARD_TX_UNLOCK(dev, txq); + } else qdisc_maybe_clear_missed(q, txq); - HARD_TX_UNLOCK(dev, txq); } else { if (root_lock) spin_lock(root_lock);