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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,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 A4B7CC65BA7 for ; Fri, 5 Oct 2018 16:23:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6B0AD21473 for ; Fri, 5 Oct 2018 16:23:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="Z6ZuTjr6" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6B0AD21473 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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 S1729942AbeJEXQK (ORCPT ); Fri, 5 Oct 2018 19:16:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:53908 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729869AbeJEXQI (ORCPT ); Fri, 5 Oct 2018 19:16:08 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3BE75214C1; Fri, 5 Oct 2018 16:16:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1538756204; bh=QeYqfDXbrCL+tSu6pgxZRm/AfhMu8UG8y/CoEmJRE+4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Z6ZuTjr6vX1a7D47i2NV6p4YS5BROoYscdXWvfzmRmDf5CdlwdRuGkkMXVSu7/mpn rmmPcQhUkJyyOt3eDPQhkKBTrR/LW51TTSVqxP7T0lw4FSCSD0i/vCQ3sfI3/PwXZ5 M4Ux9HwkCRUBxLsGn24c0eOvLGarPVpjsx4am2Ys= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Laura Abbott , "Martin K . Petersen" , Sasha Levin Subject: [PATCH AUTOSEL 4.14 10/23] scsi: iscsi: target: Don't use stack buffer for scatterlist Date: Fri, 5 Oct 2018 12:16:21 -0400 Message-Id: <20181005161634.20631-10-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181005161634.20631-1-sashal@kernel.org> References: <20181005161634.20631-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Laura Abbott [ Upstream commit 679fcae46c8b2352bba3485d521da070cfbe68e6 ] Fedora got a bug report of a crash with iSCSI: kernel BUG at include/linux/scatterlist.h:143! ... RIP: 0010:iscsit_do_crypto_hash_buf+0x154/0x180 [iscsi_target_mod] ... Call Trace: ? iscsi_target_tx_thread+0x200/0x200 [iscsi_target_mod] iscsit_get_rx_pdu+0x4cd/0xa90 [iscsi_target_mod] ? native_sched_clock+0x3e/0xa0 ? iscsi_target_tx_thread+0x200/0x200 [iscsi_target_mod] iscsi_target_rx_thread+0x81/0xf0 [iscsi_target_mod] kthread+0x120/0x140 ? kthread_create_worker_on_cpu+0x70/0x70 ret_from_fork+0x3a/0x50 This is a BUG_ON for using a stack buffer with a scatterlist. There are two cases that trigger this bug. Switch to using a dynamically allocated buffer for one case and do not assign a NULL buffer in another case. Signed-off-by: Laura Abbott Reviewed-by: Mike Christie Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/target/iscsi/iscsi_target.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c index 52fa52c20be0..d2cafdae8317 100644 --- a/drivers/target/iscsi/iscsi_target.c +++ b/drivers/target/iscsi/iscsi_target.c @@ -1421,7 +1421,8 @@ static void iscsit_do_crypto_hash_buf( sg_init_table(sg, ARRAY_SIZE(sg)); sg_set_buf(sg, buf, payload_length); - sg_set_buf(sg + 1, pad_bytes, padding); + if (padding) + sg_set_buf(sg + 1, pad_bytes, padding); ahash_request_set_crypt(hash, sg, data_crc, payload_length + padding); @@ -3942,10 +3943,14 @@ static bool iscsi_target_check_conn_state(struct iscsi_conn *conn) static void iscsit_get_rx_pdu(struct iscsi_conn *conn) { int ret; - u8 buffer[ISCSI_HDR_LEN], opcode; + u8 *buffer, opcode; u32 checksum = 0, digest = 0; struct kvec iov; + buffer = kcalloc(ISCSI_HDR_LEN, sizeof(*buffer), GFP_KERNEL); + if (!buffer) + return; + while (!kthread_should_stop()) { /* * Ensure that both TX and RX per connection kthreads @@ -3953,7 +3958,6 @@ static void iscsit_get_rx_pdu(struct iscsi_conn *conn) */ iscsit_thread_check_cpumask(conn, current, 0); - memset(buffer, 0, ISCSI_HDR_LEN); memset(&iov, 0, sizeof(struct kvec)); iov.iov_base = buffer; @@ -3962,7 +3966,7 @@ static void iscsit_get_rx_pdu(struct iscsi_conn *conn) ret = rx_data(conn, &iov, 1, ISCSI_HDR_LEN); if (ret != ISCSI_HDR_LEN) { iscsit_rx_thread_wait_for_tcp(conn); - return; + break; } if (conn->conn_ops->HeaderDigest) { @@ -3972,7 +3976,7 @@ static void iscsit_get_rx_pdu(struct iscsi_conn *conn) ret = rx_data(conn, &iov, 1, ISCSI_CRC_LEN); if (ret != ISCSI_CRC_LEN) { iscsit_rx_thread_wait_for_tcp(conn); - return; + break; } iscsit_do_crypto_hash_buf(conn->conn_rx_hash, @@ -3996,7 +4000,7 @@ static void iscsit_get_rx_pdu(struct iscsi_conn *conn) } if (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT) - return; + break; opcode = buffer[0] & ISCSI_OPCODE_MASK; @@ -4007,13 +4011,15 @@ static void iscsit_get_rx_pdu(struct iscsi_conn *conn) " while in Discovery Session, rejecting.\n", opcode); iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR, buffer); - return; + break; } ret = iscsi_target_rx_opcode(conn, buffer); if (ret < 0) - return; + break; } + + kfree(buffer); } int iscsi_target_rx_thread(void *arg) -- 2.17.1