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=-19.4 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, 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 472C0C4338F for ; Mon, 2 Aug 2021 13:51:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3288261106 for ; Mon, 2 Aug 2021 13:51:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234380AbhHBNvl (ORCPT ); Mon, 2 Aug 2021 09:51:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:33536 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234998AbhHBNux (ORCPT ); Mon, 2 Aug 2021 09:50:53 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 687C16112D; Mon, 2 Aug 2021 13:50:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1627912236; bh=rnZkppms87SENbqQ0YwaRx8DDxeQ3FjXlqmpA+j/hmA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=X8aY7dTu1r3d7NDYZMbdGS9bq2PJtQyEORHLKxIBbLqp5lbgPMdFvAxR/sFBuacoO S64/rQoYFoRKCz3G6dRIZOPuTABlYwyzr6kRQVDTO6rIq707nwH9D4AIqt0+Xz7aXF +x02auAklaEjlmp7uA3F6bQzbcicOcOWRjJ6Ak1M= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vlad Buslov , Jamal Hadi Salim , Jiri Pirko , Cong Wang , "David S. Miller" , Sasha Levin , syzbot+b47bc4f247856fb4d9e1@syzkaller.appspotmail.com Subject: [PATCH 5.4 01/40] net_sched: check error pointer in tcf_dump_walker() Date: Mon, 2 Aug 2021 15:44:41 +0200 Message-Id: <20210802134335.454274504@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210802134335.408294521@linuxfoundation.org> References: <20210802134335.408294521@linuxfoundation.org> User-Agent: quilt/0.66 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Cong Wang [ Upstream commit 580e4273d7a883ececfefa692c1f96bdbacb99b5 ] Although we take RTNL on dump path, it is possible to skip RTNL on insertion path. So the following race condition is possible: rtnl_lock() // no rtnl lock mutex_lock(&idrinfo->lock); // insert ERR_PTR(-EBUSY) mutex_unlock(&idrinfo->lock); tc_dump_action() rtnl_unlock() So we have to skip those temporary -EBUSY entries on dump path too. Reported-and-tested-by: syzbot+b47bc4f247856fb4d9e1@syzkaller.appspotmail.com Fixes: 0fedc63fadf0 ("net_sched: commit action insertions together") Cc: Vlad Buslov Cc: Jamal Hadi Salim Cc: Jiri Pirko Signed-off-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/sched/act_api.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/sched/act_api.c +++ b/net/sched/act_api.c @@ -231,6 +231,8 @@ static int tcf_dump_walker(struct tcf_id index++; if (index < s_i) continue; + if (IS_ERR(p)) + continue; if (jiffy_since && time_after(jiffy_since,