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 0D3DFC4167B for ; Wed, 28 Dec 2022 16:52:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235163AbiL1QwY (ORCPT ); Wed, 28 Dec 2022 11:52:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45828 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235223AbiL1QwB (ORCPT ); Wed, 28 Dec 2022 11:52:01 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EC4CD1DA49 for ; Wed, 28 Dec 2022 08:46:21 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 7C7B8B81729 for ; Wed, 28 Dec 2022 16:46:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D0D50C433EF; Wed, 28 Dec 2022 16:46:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1672245979; bh=meXrmIHc4uB22MVvnpTkZ0t6/lXPGSax7WRu1NPzbQo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ti4m6rScRMGdYc9DhaJP/nnMfKgaG2pQdgxpFr0IN0jloX3iLDSmfNwJvLClWoO3i Lr5q3fyq59cb0mrK16qzFWgfvsv05efDH3camPBJTSWKAxl7n5ngufVMcCMegOXPbA 6WLy7xCjXcGWLlX+StoH2YFnSoBOfnMTvsFz3yPo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Maurizio Lombardi , Mike Christie , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 6.0 0990/1073] scsi: target: iscsi: Fix a race condition between login_work and the login thread Date: Wed, 28 Dec 2022 15:42:58 +0100 Message-Id: <20221228144354.996907584@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20221228144328.162723588@linuxfoundation.org> References: <20221228144328.162723588@linuxfoundation.org> User-Agent: quilt/0.67 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: Maurizio Lombardi [ Upstream commit fec1b2fa62c162d03f5dcd7b03e3c89d3116d49f ] In case a malicious initiator sends some random data immediately after a login PDU; the iscsi_target_sk_data_ready() callback will schedule the login_work and, at the same time, the negotiation may end without clearing the LOGIN_FLAGS_INITIAL_PDU flag (because no additional PDU exchanges are required to complete the login). The login has been completed but the login_work function will find the LOGIN_FLAGS_INITIAL_PDU flag set and will never stop from rescheduling itself; at this point, if the initiator drops the connection, the iscsit_conn structure will be freed, login_work will dereference a released socket structure and the kernel crashes. BUG: kernel NULL pointer dereference, address: 0000000000000230 PF: supervisor write access in kernel mode PF: error_code(0x0002) - not-present page Workqueue: events iscsi_target_do_login_rx [iscsi_target_mod] RIP: 0010:_raw_read_lock_bh+0x15/0x30 Call trace: iscsi_target_do_login_rx+0x75/0x3f0 [iscsi_target_mod] process_one_work+0x1e8/0x3c0 Fix this bug by forcing login_work to stop after the login has been completed and the socket callbacks have been restored. Add a comment to clearify the return values of iscsi_target_do_login() Signed-off-by: Maurizio Lombardi Link: https://lore.kernel.org/r/20221115125638.102517-1-mlombard@redhat.com Reviewed-by: Mike Christie Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/target/iscsi/iscsi_target_nego.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/target/iscsi/iscsi_target_nego.c b/drivers/target/iscsi/iscsi_target_nego.c index f2919319ad38..ff49c8f3fe24 100644 --- a/drivers/target/iscsi/iscsi_target_nego.c +++ b/drivers/target/iscsi/iscsi_target_nego.c @@ -1018,6 +1018,13 @@ static int iscsi_target_handle_csg_one(struct iscsit_conn *conn, struct iscsi_lo return 0; } +/* + * RETURN VALUE: + * + * 1 = Login successful + * -1 = Login failed + * 0 = More PDU exchanges required + */ static int iscsi_target_do_login(struct iscsit_conn *conn, struct iscsi_login *login) { int pdu_count = 0; @@ -1363,12 +1370,13 @@ int iscsi_target_start_negotiation( ret = -1; if (ret < 0) { - cancel_delayed_work_sync(&conn->login_work); iscsi_target_restore_sock_callbacks(conn); iscsi_remove_failed_auth_entry(conn); } - if (ret != 0) + if (ret != 0) { + cancel_delayed_work_sync(&conn->login_work); iscsi_target_nego_release(conn); + } return ret; } -- 2.35.1