From patchwork Mon Aug 7 03:11:27 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Nicholas A. Bellinger" X-Patchwork-Id: 9884319 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 0448060360 for ; Mon, 7 Aug 2017 03:05:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0279128449 for ; Mon, 7 Aug 2017 03:05:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EB62F28533; Mon, 7 Aug 2017 03:05:30 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4BACF28449 for ; Mon, 7 Aug 2017 03:05:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751437AbdHGDF3 (ORCPT ); Sun, 6 Aug 2017 23:05:29 -0400 Received: from mail.linux-iscsi.org ([67.23.28.174]:38684 "EHLO linux-iscsi.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751407AbdHGDF2 (ORCPT ); Sun, 6 Aug 2017 23:05:28 -0400 Received: from linux-iscsi.org (localhost [127.0.0.1]) by linux-iscsi.org (Postfix) with ESMTP id 9AF4A40B25; Mon, 7 Aug 2017 03:11:30 +0000 (UTC) From: "Nicholas A. Bellinger" To: target-devel Cc: stable , Greg-KH , Xiubo Li Subject: [PATCH-v4.12.y 2/2] tcmu: Fix possbile memory leak / OOPs when recalculating cmd base size Date: Mon, 7 Aug 2017 03:11:27 +0000 Message-Id: <1502075487-19236-3-git-send-email-nab@linux-iscsi.org> X-Mailer: git-send-email 1.7.2.5 In-Reply-To: <1502075487-19236-1-git-send-email-nab@linux-iscsi.org> References: <1502075487-19236-1-git-send-email-nab@linux-iscsi.org> Sender: target-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: target-devel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Xiubo Li commit b3743c71b7c33a126d6d8942bb268775987400ec upstream. For all the entries allocated from the ring cmd area, the memory is something like the stack memory, which will always reserve the old data, so the entry->req.iov_bidi_cnt maybe none zero. On some environments, the crash could be reproduce very easy and some not. The following is the crash core trace as reported by Damien: [ 240.143969] CPU: 0 PID: 1285 Comm: iscsi_trx Not tainted 4.12.0-rc1+ #3 [ 240.150607] Hardware name: ASUS All Series/H87-PRO, BIOS 2104 10/28/2014 [ 240.157331] task: ffff8807de4f5800 task.stack: ffffc900047dc000 [ 240.163270] RIP: 0010:memcpy_erms+0x6/0x10 [ 240.167377] RSP: 0018:ffffc900047dfc68 EFLAGS: 00010202 [ 240.172621] RAX: ffffc9065db85540 RBX: ffff8807f7980000 RCX: 0000000000000010 [ 240.179771] RDX: 0000000000000010 RSI: ffff8807de574fe0 RDI: ffffc9065db85540 [ 240.186930] RBP: ffffc900047dfd30 R08: ffff8807de41b000 R09: 0000000000000000 [ 240.194088] R10: 0000000000000040 R11: ffff8807e9b726f0 R12: 00000006565726b0 [ 240.201246] R13: ffffc90007612ea0 R14: 000000065657d540 R15: 0000000000000000 [ 240.208397] FS: 0000000000000000(0000) GS:ffff88081fa00000(0000) knlGS:0000000000000000 [ 240.216510] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 240.222280] CR2: ffffc9065db85540 CR3: 0000000001c0f000 CR4: 00000000001406f0 [ 240.229430] Call Trace: [ 240.231887] ? tcmu_queue_cmd+0x83c/0xa80 [ 240.235916] ? target_check_reservation+0xcd/0x6f0 [ 240.240725] __target_execute_cmd+0x27/0xa0 [ 240.244918] target_execute_cmd+0x232/0x2c0 [ 240.249124] ? __local_bh_enable_ip+0x64/0xa0 [ 240.253499] iscsit_execute_cmd+0x20d/0x270 [ 240.257693] iscsit_sequence_cmd+0x110/0x190 [ 240.261985] iscsit_get_rx_pdu+0x360/0xc80 [ 240.267565] ? iscsi_target_rx_thread+0x54/0xd0 [ 240.273571] iscsi_target_rx_thread+0x9a/0xd0 [ 240.279413] kthread+0x113/0x150 [ 240.284120] ? iscsi_target_tx_thread+0x1e0/0x1e0 [ 240.290297] ? kthread_create_on_node+0x40/0x40 [ 240.296297] ret_from_fork+0x2e/0x40 [ 240.301332] Code: 90 90 90 90 90 eb 1e 0f 1f 00 48 89 f8 48 89 d1 48 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 c3 66 0f 1f 44 00 00 48 89 f8 48 89 d1 a4 c3 0f 1f 80 00 00 00 00 48 89 f8 48 83 fa 20 72 7e 40 38 [ 240.321751] RIP: memcpy_erms+0x6/0x10 RSP: ffffc900047dfc68 [ 240.328838] CR2: ffffc9065db85540 [ 240.333667] ---[ end trace b7e5354cfb54d08b ]--- To fix this, just memset all the entry memory before using it, and also to be more readable we adjust the bidi code. Fixed: fe25cc34795(tcmu: Recalculate the tcmu_cmd size to save cmd area memories) Reported-by: Bryant G. Ly Tested-by: Bryant G. Ly Reported-by: Damien Le Moal Tested-by: Damien Le Moal Reviewed-by: Mike Christie Signed-off-by: Xiubo Li Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_user.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index c8b63b8..0580422 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -437,7 +437,7 @@ static int scatter_data_area(struct tcmu_dev *udev, to_offset = get_block_offset_user(udev, dbi, block_remaining); offset = DATA_BLOCK_SIZE - block_remaining; - to = (void *)(unsigned long)to + offset; + to += offset; if (*iov_cnt != 0 && to_offset == iov_tail(udev, *iov)) { @@ -510,7 +510,7 @@ static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd, copy_bytes = min_t(size_t, sg_remaining, block_remaining); offset = DATA_BLOCK_SIZE - block_remaining; - from = (void *)(unsigned long)from + offset; + from += offset; tcmu_flush_dcache_range(from, copy_bytes); memcpy(to + sg->length - sg_remaining, from, copy_bytes); @@ -714,10 +714,9 @@ static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd, } entry = (void *) mb + CMDR_OFF + cmd_head; + memset(entry, 0, command_size); tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD); entry->hdr.cmd_id = tcmu_cmd->cmd_id; - entry->hdr.kflags = 0; - entry->hdr.uflags = 0; /* Handle allocating space from the data area */ tcmu_cmd_reset_dbi_cur(tcmu_cmd); @@ -736,11 +735,10 @@ static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd, return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; } entry->req.iov_cnt = iov_cnt; - entry->req.iov_dif_cnt = 0; /* Handle BIDI commands */ + iov_cnt = 0; if (se_cmd->se_cmd_flags & SCF_BIDI) { - iov_cnt = 0; iov++; ret = scatter_data_area(udev, tcmu_cmd, se_cmd->t_bidi_data_sg, @@ -753,8 +751,8 @@ static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd, pr_err("tcmu: alloc and scatter bidi data failed\n"); return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; } - entry->req.iov_bidi_cnt = iov_cnt; } + entry->req.iov_bidi_cnt = iov_cnt; /* * Recalaulate the command's base size and size according