From patchwork Thu Jul 28 13:28:20 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Namjae Jeon X-Patchwork-Id: 12931305 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 C1500C04A68 for ; Thu, 28 Jul 2022 13:33:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229862AbiG1Ndb (ORCPT ); Thu, 28 Jul 2022 09:33:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40172 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230309AbiG1Nda (ORCPT ); Thu, 28 Jul 2022 09:33:30 -0400 Received: from mail-pj1-f53.google.com (mail-pj1-f53.google.com [209.85.216.53]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1D74D5C34F for ; Thu, 28 Jul 2022 06:33:28 -0700 (PDT) Received: by mail-pj1-f53.google.com with SMTP id f11-20020a17090a4a8b00b001f2f7e32d03so5211057pjh.0 for ; Thu, 28 Jul 2022 06:33:28 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=k9KEDV9PXE/NMjLMHOZlUy2f7/0QT8HzaDNT157sTmg=; b=TUIHjIxatZtJvUYzdpP3XSKs3n3sgVe97r740+kvC7fx5eqvLaH97iX4rMAJ8tX0Ge zxj31aIJbIE9mnGlsHXuOncQyg9uygbE3lVIMlJ8tYW5fnzwcDRSXqBjmX2OSD7B7fWz tihQUABEFFwWcc5UpJD/cs1sHvWj0YhNgcYTJ+risHgH4QAbx6m7YI3j1X2yD2uF3cWH r+MQjqYCICyiezgpyMt3sub4Banuy8SVjJ+YhSLB4jzxVRnaHY570nV5qjgzVTmYEQOO 6MMrxayngNxFS5yOkeumVtmKO2xfwYtoWswnjNxErdiHHqBOxxMs+FZ4FEZ9HZeFv21Y PCuw== X-Gm-Message-State: AJIora98wxvwTs0f3ct9FE5iY8dH1BsmrEopcQzuOJTBhAyCuD/QwiiU HKSeebV/D3tU/DcDaf8tchQdg7yj9LA= X-Google-Smtp-Source: AGRyM1utwJXnNndMOy9T2f8mJJsZbXtb6ifrGYWn5jBytNurzXg2bryJ49+4QQYDkqzBZuuOYLNOnw== X-Received: by 2002:a17:90a:2c44:b0:1f3:ad8:6359 with SMTP id p4-20020a17090a2c4400b001f30ad86359mr9004663pjm.181.1659015206920; Thu, 28 Jul 2022 06:33:26 -0700 (PDT) Received: from localhost.localdomain ([211.49.23.9]) by smtp.gmail.com with ESMTPSA id m14-20020a63710e000000b0041b667a1b69sm960078pgc.36.2022.07.28.06.33.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 28 Jul 2022 06:33:26 -0700 (PDT) From: Namjae Jeon To: linux-cifs@vger.kernel.org Cc: smfrench@gmail.com, hyc.lee@gmail.com, senozhatsky@chromium.org, gregkh@linuxfoundation.org, Namjae Jeon , zdi-disclosures@trendmicro.com Subject: [PATCH 3/5] ksmbd: prevent out of bound read for SMB2_WRITE Date: Thu, 28 Jul 2022 22:28:20 +0900 Message-Id: <20220728132822.6311-3-linkinjeon@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220728132822.6311-1-linkinjeon@kernel.org> References: <20220728132822.6311-1-linkinjeon@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org From: Hyunchul Lee OOB read memory can be written to a file, if DataOffset is 0 and Length is too large in SMB2_WRITE request of compound request. To prevent this, when checking the length of the data area of SMB2_WRITE in smb2_get_data_area_len(), let the minimum of DataOffset be the size of SMB2 header + the size of SMB2_WRITE header. This bug can lead an oops looking something like: [ 798.008715] BUG: KASAN: slab-out-of-bounds in copy_page_from_iter_atomic+0xd3d/0x14b0 [ 798.008724] Read of size 252 at addr ffff88800f863e90 by task kworker/0:2/2859 ... [ 798.008754] Call Trace: [ 798.008756] [ 798.008759] dump_stack_lvl+0x49/0x5f [ 798.008764] print_report.cold+0x5e/0x5cf [ 798.008768] ? __filemap_get_folio+0x285/0x6d0 [ 798.008774] ? copy_page_from_iter_atomic+0xd3d/0x14b0 [ 798.008777] kasan_report+0xaa/0x120 [ 798.008781] ? copy_page_from_iter_atomic+0xd3d/0x14b0 [ 798.008784] kasan_check_range+0x100/0x1e0 [ 798.008788] memcpy+0x24/0x60 [ 798.008792] copy_page_from_iter_atomic+0xd3d/0x14b0 [ 798.008795] ? pagecache_get_page+0x53/0x160 [ 798.008799] ? iov_iter_get_pages_alloc+0x1590/0x1590 [ 798.008803] ? ext4_write_begin+0xfc0/0xfc0 [ 798.008807] ? current_time+0x72/0x210 [ 798.008811] generic_perform_write+0x2c8/0x530 [ 798.008816] ? filemap_fdatawrite_wbc+0x180/0x180 [ 798.008820] ? down_write+0xb4/0x120 [ 798.008824] ? down_write_killable+0x130/0x130 [ 798.008829] ext4_buffered_write_iter+0x137/0x2c0 [ 798.008833] ext4_file_write_iter+0x40b/0x1490 [ 798.008837] ? __fsnotify_parent+0x275/0xb20 [ 798.008842] ? __fsnotify_update_child_dentry_flags+0x2c0/0x2c0 [ 798.008846] ? ext4_buffered_write_iter+0x2c0/0x2c0 [ 798.008851] __kernel_write+0x3a1/0xa70 [ 798.008855] ? __x64_sys_preadv2+0x160/0x160 [ 798.008860] ? security_file_permission+0x4a/0xa0 [ 798.008865] kernel_write+0xbb/0x360 [ 798.008869] ksmbd_vfs_write+0x27e/0xb90 [ksmbd] [ 798.008881] ? ksmbd_vfs_read+0x830/0x830 [ksmbd] [ 798.008892] ? _raw_read_unlock+0x2a/0x50 [ 798.008896] smb2_write+0xb45/0x14e0 [ksmbd] [ 798.008909] ? __kasan_check_write+0x14/0x20 [ 798.008912] ? _raw_spin_lock_bh+0xd0/0xe0 [ 798.008916] ? smb2_read+0x15e0/0x15e0 [ksmbd] [ 798.008927] ? memcpy+0x4e/0x60 [ 798.008931] ? _raw_spin_unlock+0x19/0x30 [ 798.008934] ? ksmbd_smb2_check_message+0x16af/0x2350 [ksmbd] [ 798.008946] ? _raw_spin_lock_bh+0xe0/0xe0 [ 798.008950] handle_ksmbd_work+0x30e/0x1020 [ksmbd] [ 798.008962] process_one_work+0x778/0x11c0 [ 798.008966] ? _raw_spin_lock_irq+0x8e/0xe0 [ 798.008970] worker_thread+0x544/0x1180 [ 798.008973] ? __cpuidle_text_end+0x4/0x4 [ 798.008977] kthread+0x282/0x320 [ 798.008982] ? process_one_work+0x11c0/0x11c0 [ 798.008985] ? kthread_complete_and_exit+0x30/0x30 [ 798.008989] ret_from_fork+0x1f/0x30 [ 798.008995] Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-17817 Signed-off-by: Hyunchul Lee Acked-by: Namjae Jeon --- fs/ksmbd/smb2misc.c | 7 +++++-- fs/ksmbd/smb2pdu.c | 7 ++----- 2 files changed, 7 insertions(+), 7 deletions(-) diff --git a/fs/ksmbd/smb2misc.c b/fs/ksmbd/smb2misc.c index f8f456377a51..aa1e663d9deb 100644 --- a/fs/ksmbd/smb2misc.c +++ b/fs/ksmbd/smb2misc.c @@ -136,8 +136,11 @@ static int smb2_get_data_area_len(unsigned int *off, unsigned int *len, *len = le16_to_cpu(((struct smb2_read_req *)hdr)->ReadChannelInfoLength); break; case SMB2_WRITE: - if (((struct smb2_write_req *)hdr)->DataOffset) { - *off = le16_to_cpu(((struct smb2_write_req *)hdr)->DataOffset); + if (((struct smb2_write_req *)hdr)->DataOffset || + ((struct smb2_write_req *)hdr)->Length) { + *off = max_t(unsigned int, + le16_to_cpu(((struct smb2_write_req *)hdr)->DataOffset), + offsetof(struct smb2_write_req, Buffer)); *len = le32_to_cpu(((struct smb2_write_req *)hdr)->Length); break; } diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index 7ecb6d87ae3e..1bad4f729160 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -6514,14 +6514,11 @@ int smb2_write(struct ksmbd_work *work) writethrough = true; if (is_rdma_channel == false) { - if ((u64)le16_to_cpu(req->DataOffset) + length > - get_rfc1002_len(work->request_buf)) { - pr_err("invalid write data offset %u, smb_len %u\n", - le16_to_cpu(req->DataOffset), - get_rfc1002_len(work->request_buf)); + if (req->DataOffset < offsetof(struct smb2_write_req, Buffer)) { err = -EINVAL; goto out; } + data_buf = (char *)(((char *)&req->hdr.ProtocolId) + le16_to_cpu(req->DataOffset));