From patchwork Fri Jul 29 01:13:20 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Namjae Jeon X-Patchwork-Id: 12931857 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 C98B8C00140 for ; Fri, 29 Jul 2022 01:13:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233400AbiG2BNh (ORCPT ); Thu, 28 Jul 2022 21:13:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54714 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229535AbiG2BNg (ORCPT ); Thu, 28 Jul 2022 21:13:36 -0400 Received: from mail-pg1-f170.google.com (mail-pg1-f170.google.com [209.85.215.170]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1BBEB6BD40; Thu, 28 Jul 2022 18:13:32 -0700 (PDT) Received: by mail-pg1-f170.google.com with SMTP id 6so2829275pgb.13; Thu, 28 Jul 2022 18:13:32 -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:mime-version :content-transfer-encoding; bh=nWX8earIdDVsBRHDmC8mWA0KRrT14T7sOCqzUxZsmpc=; b=dbQJnzLn/XY0EOMhN9+SvKvdalpA61CDHkOApoHafcsM1VTJYxHlGtV1KJu7flk5ui x5LthH6Z7jB7V30Ik/wtSGpLwNnkF+oqwD0W8MUYLYR0OjG5k7oPrSzgs/T9QKxdHFcZ KVtATv7bLk9pdl0p0oHNCUVcO7nVbczJDTLmPLnrLyvLpYWsMXiwcIXhYpHA4wmn8urR MG0r63aCGVhACsCA0tNY8V3iVrvo2YzRS8v5z61C2NZOx+i9uCkhzNdD1H6/G5ZbC1Ba 4QTGwcqLXNaErKPhTHmh9QwY9g11TFPg7UH9RFFh5mO8ysB7rXhW/HY1iuqufxVrUbj/ 0OKw== X-Gm-Message-State: AJIora9fbfHhIMpjxLApl5E7v2YEXEatptBaKehT+Rud5fJesHsHRvL6 pp7R/vhLGkEmisai/IUErh7FiMSHFXo= X-Google-Smtp-Source: AGRyM1vogZlzFRFSU+3ZEJOjZG+2fCWK/dgX/N1bYZyquDNCmATqsNJk+xAJThoNtn9g2tmYtftD2g== X-Received: by 2002:a63:6c83:0:b0:419:aa0d:216c with SMTP id h125-20020a636c83000000b00419aa0d216cmr1072865pgc.328.1659057211092; Thu, 28 Jul 2022 18:13:31 -0700 (PDT) Received: from localhost.localdomain ([211.49.23.9]) by smtp.gmail.com with ESMTPSA id mn17-20020a17090b189100b001f23db09351sm1642673pjb.46.2022.07.28.18.13.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 28 Jul 2022 18:13:30 -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 , stable@vger.kernel.org, zdi-disclosures@trendmicro.com Subject: [PATCH v3] ksmbd: prevent out of bound read for SMB2_WRITE Date: Fri, 29 Jul 2022 10:13:20 +0900 Message-Id: <20220729011321.15663-1-linkinjeon@kernel.org> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org 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] Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-17817 Signed-off-by: Hyunchul Lee Acked-by: Namjae Jeon --- v2: - add missing fixes and stable tags. v3: - fix sparse warnings reported from kernel test robot. fs/ksmbd/smb2misc.c | 7 +++++-- fs/ksmbd/smb2pdu.c | 8 +++----- 2 files changed, 8 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..ea47aa0262ee 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -6514,14 +6514,12 @@ 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 (le16_to_cpu(req->DataOffset) < + offsetof(struct smb2_write_req, Buffer)) { err = -EINVAL; goto out; } + data_buf = (char *)(((char *)&req->hdr.ProtocolId) + le16_to_cpu(req->DataOffset));