From patchwork Thu Nov 10 12:26:06 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: shaozhengchao X-Patchwork-Id: 13038742 X-Patchwork-Delegate: kuba@kernel.org 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 37C62C4332F for ; Thu, 10 Nov 2022 12:19:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230500AbiKJMTT (ORCPT ); Thu, 10 Nov 2022 07:19:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36246 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230261AbiKJMTO (ORCPT ); Thu, 10 Nov 2022 07:19:14 -0500 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E39DB71F37 for ; Thu, 10 Nov 2022 04:19:12 -0800 (PST) Received: from dggpeml500026.china.huawei.com (unknown [172.30.72.57]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4N7LV93zrFz15MMt; Thu, 10 Nov 2022 20:18:57 +0800 (CST) Received: from huawei.com (10.175.101.6) by dggpeml500026.china.huawei.com (7.185.36.106) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Thu, 10 Nov 2022 20:19:10 +0800 From: Zhengchao Shao To: , , , , , , , , CC: , , Subject: [PATCH net] net/9p: fix issue of list_del corruption in p9_fd_cancel() Date: Thu, 10 Nov 2022 20:26:06 +0800 Message-ID: <20221110122606.383352-1-shaozhengchao@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [10.175.101.6] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpeml500026.china.huawei.com (7.185.36.106) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org Syz reported the following issue: kernel BUG at lib/list_debug.c:53! invalid opcode: 0000 [#1] PREEMPT SMP KASAN RIP: 0010:__list_del_entry_valid.cold+0x5c/0x72 Call Trace: p9_fd_cancel+0xb1/0x270 p9_client_rpc+0x8ea/0xba0 p9_client_create+0x9c0/0xed0 v9fs_session_init+0x1e0/0x1620 v9fs_mount+0xba/0xb80 legacy_get_tree+0x103/0x200 vfs_get_tree+0x89/0x2d0 path_mount+0x4c0/0x1ac0 __x64_sys_mount+0x33b/0x430 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 The process is as follows: Thread A: Thread B: p9_poll_workfn() p9_client_create() ... ... p9_conn_cancel() p9_fd_cancel() list_del() ... ... list_del() //list_del corruption There is no lock protection when deleting list in p9_conn_cancel(). After deleting list in Thread A, thread B will delete the same list again. It will cause issue of list_del corruption. Fixes: 52f1c45dde91 ("9p: trans_fd/p9_conn_cancel: drop client lock earlier") Reported-by: syzbot+9b69b8d10ab4a7d88056@syzkaller.appspotmail.com Signed-off-by: Zhengchao Shao --- v2: set req status when removing list --- net/9p/trans_fd.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c index 56a186768750..bd28e63d7666 100644 --- a/net/9p/trans_fd.c +++ b/net/9p/trans_fd.c @@ -202,9 +202,11 @@ static void p9_conn_cancel(struct p9_conn *m, int err) list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) { list_move(&req->req_list, &cancel_list); + req->status = REQ_STATUS_ERROR; } list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) { list_move(&req->req_list, &cancel_list); + req->status = REQ_STATUS_ERROR; } spin_unlock(&m->req_lock);