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=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 04D8FECDFB8 for ; Fri, 20 Jul 2018 13:28:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B068620652 for ; Fri, 20 Jul 2018 13:28:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Y8FitExC" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B068620652 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731991AbeGTOQl (ORCPT ); Fri, 20 Jul 2018 10:16:41 -0400 Received: from mail-lf1-f67.google.com ([209.85.167.67]:39275 "EHLO mail-lf1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731417AbeGTOQk (ORCPT ); Fri, 20 Jul 2018 10:16:40 -0400 Received: by mail-lf1-f67.google.com with SMTP id a134-v6so1807342lfe.6; Fri, 20 Jul 2018 06:28:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=k8XIvvLyAABzUp2LyIk88Y5yrKyYx/KgnzhQ7AveH5g=; b=Y8FitExC7F5iZif23xx3LdSe0TuupubDZFtPMBqzXgG7I0jMt2SjlaebYLUBntTGNU q7WQ247bpzrV18qcLSV/EZpO7VyT1BENHheyM1jiINmsuHE75P1pV6IS5DdxsMPemOiJ uy0Q1QFs9dteIslCIbH1MbgH4L4tLkNI83xSLzgRv3ICUqaxD3TSUAcGMjSrnETqETE/ OYTVflgfPuKOG3vovE9KxGb/Ij5D4Q49X69635dR4d3AVr5FUlAhuole0SqHIYkp+Zhm C8DSJmpQO3czVNJ0gunuZauLIY5AXNqDxvyNVEm9N8/q6auyVWUwzKN81tFP8/A9xhL8 fw2g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=k8XIvvLyAABzUp2LyIk88Y5yrKyYx/KgnzhQ7AveH5g=; b=uefAjZlYI1XNSMT0CfWcGksl0y19xOIJz5SjpXXeiX4gNYWo45jIJ9jfgHqohh0tco MHBL0Pr3XCkOqukwpxHFkcX7BuJ69m/9mrVwOFXERGdwi7POFf4vvj7vSJFJEoYzG3Qk CYi30zZ71URtM+DNvNo4DefGlWmzB33ZLU+CW/lhYMPtGkrNiyoD7JndkJu47cpKMykp f8D3gASkDbgXDZIDH/v/AwEVLSleGvSns1z8pfRz2tT2dNffg4jmc2S4ewuFvgOADgtp aNAi5CQSRZw7RnY9JZ/BR3oMVCTGsQ7jdlNCPNXMUUgrqmStGZ6rAPSYbs+RrPFcLKhy GZKw== X-Gm-Message-State: AOUpUlEpQc3OWrSg3vi0mFifoN9p0jXE3Js4lpfuH+JE3jpNHtxzHKYV dyhl+O3Dlk+UMKfgSGorrvM= X-Google-Smtp-Source: AAOMgpe3e5K3/27QwS52QnI1/RUsZsbVUH7TvWsm6D6Iwnqk8VQfoT00a2VLQ+k8TUnVDPnW5I9hlg== X-Received: by 2002:a19:cf95:: with SMTP id f143-v6mr1497258lfg.101.1532093301082; Fri, 20 Jul 2018 06:28:21 -0700 (PDT) Received: from debian-tom.lan ([2001:2012:22e:1b00:f2e2:9015:9262:3fde]) by smtp.gmail.com with ESMTPSA id g28-v6sm299029lfh.92.2018.07.20.06.28.19 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 20 Jul 2018 06:28:20 -0700 (PDT) From: Tomas Bortoli To: ericvh@gmail.com, rminnich@sandia.gov, lucho@ionkov.net Cc: jiangyiwen@huawei.com, davem@davemloft.net, v9fs-developer@lists.sourceforge.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller@googlegroups.com, Tomas Bortoli Subject: [PATCH] net/9p/trans_fd.c: fix double list_del() and race in access Date: Fri, 20 Jul 2018 15:28:01 +0200 Message-Id: <20180720132801.22749-1-tomasbortoli@gmail.com> X-Mailer: git-send-email 2.11.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch uses list_del_init() instead of list_del() to eliminate "req_list". This to prevent double list_del()'s calls to the same list from provoking a GPF. Furthermore, this patch fixes an access to "req_list" that was made without getting the relative lock. Signed-off-by: Tomas Bortoli Reported-by: syzbot+735d926e9d1317c3310c@syzkaller.appspotmail.com --- net/9p/trans_fd.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c index a64b01c56e30..131bb1f059e6 100644 --- a/net/9p/trans_fd.c +++ b/net/9p/trans_fd.c @@ -223,7 +223,9 @@ static void p9_conn_cancel(struct p9_conn *m, int err) list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) { p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req); - list_del(&req->req_list); + spin_lock_irqsave(&m->client->lock, flags); + list_del_init(&req->req_list); + spin_unlock_irqrestore(&m->client->lock, flags); if (!req->t_err) req->t_err = err; p9_client_cb(m->client, req, REQ_STATUS_ERROR); @@ -369,7 +371,7 @@ static void p9_read_work(struct work_struct *work) spin_lock(&m->client->lock); if (m->req->status != REQ_STATUS_ERROR) status = REQ_STATUS_RCVD; - list_del(&m->req->req_list); + list_del_init(&m->req->req_list); spin_unlock(&m->client->lock); p9_client_cb(m->client, m->req, status); m->rc.sdata = NULL; @@ -684,7 +686,7 @@ static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req) spin_lock(&client->lock); if (req->status == REQ_STATUS_UNSENT) { - list_del(&req->req_list); + list_del_init(&req->req_list); req->status = REQ_STATUS_FLSHD; ret = 0; } @@ -701,7 +703,7 @@ static int p9_fd_cancelled(struct p9_client *client, struct p9_req_t *req) * remove it from the list. */ spin_lock(&client->lock); - list_del(&req->req_list); + list_del_init(&req->req_list); spin_unlock(&client->lock); return 0; -- 2.11.0