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 C4E86C7EE23 for ; Wed, 17 May 2023 11:05:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230456AbjEQLF2 (ORCPT ); Wed, 17 May 2023 07:05:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51078 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230391AbjEQLF0 (ORCPT ); Wed, 17 May 2023 07:05:26 -0400 Received: from mail-pg1-x529.google.com (mail-pg1-x529.google.com [IPv6:2607:f8b0:4864:20::529]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E50B8ED for ; Wed, 17 May 2023 04:05:10 -0700 (PDT) Received: by mail-pg1-x529.google.com with SMTP id 41be03b00d2f7-51b33c72686so413838a12.1 for ; Wed, 17 May 2023 04:05:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1684321510; x=1686913510; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=0dBeyJPRhXrYoMdL7UNGXjkGvgsaNG56xw0crWEgD48=; b=fZs9TRe94gxN+oZAjsjYdOyM87U2q+W7GnbL9O60H1JvP1tqtUwC17pq0QUKlJGGFN sWMUAQ6mL7j2Ri0G2lAaq8qFlqCPJeoyQWrFaE/QUnYuSEaZMdxtM0dVjt21cYb+NRtR fIyDlqZyNiUL5N4kihdoU22vynJr6u3AsCP9o= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1684321510; x=1686913510; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=0dBeyJPRhXrYoMdL7UNGXjkGvgsaNG56xw0crWEgD48=; b=O4TRgiQzotiW3gcV+aEwnfBJ5xbMLWCaD0PZPxbDZAhveDYIsjDE7OrxNNiH9yRyw+ f37yy7X1IUP/cu0b1ydNFiTb9V74hjPQP0NzecacwgzVzsq5MEL9TRKxATpKygl/9MA2 4esFPOwXpqfLhtm0AsnhX4gCeapkJKSkSFFrutGBWz3b9vaByellpQTr13mhSJPqD0lt FdHKiXpARu463ywnsaUfq8wj6tl12X+jR49CGR9LqBi3kqaVd6quSVc2Crn0k8TijCyL Zr42s+H5as5kPY1cgf6gSK4apPcJFMMoEXyHfZpxpQk8Q0wpKR+tUYlOfvOpTnzOCdvp y8lg== X-Gm-Message-State: AC+VfDy6a59uJGPrsW9bHx/BNnQb+w9cRY5+W0P6NMcGqMmUrTmhGdf+ dKdT87mOzkYTCm6yYjpRrLNx1A== X-Google-Smtp-Source: ACHHUZ59gWUw0K3SC48NuPVRI9YGaVxsWqMaxdfEEeT3DVeqP2cx1W2fGL4BWa7WNY3bj92hc4UihQ== X-Received: by 2002:a17:90b:1e41:b0:250:a6bd:cb4a with SMTP id pi1-20020a17090b1e4100b00250a6bdcb4amr29708157pjb.29.1684321510346; Wed, 17 May 2023 04:05:10 -0700 (PDT) Received: from google.com ([110.11.159.72]) by smtp.gmail.com with ESMTPSA id ck6-20020a17090afe0600b0024ffa911e2asm1281337pjb.51.2023.05.17.04.05.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 May 2023 04:05:10 -0700 (PDT) Date: Wed, 17 May 2023 20:05:05 +0900 From: Sergey Senozhatsky To: HexRabbit Cc: linkinjeon@kernel.org, sfrench@samba.org, senozhatsky@chromium.org, tom@talpey.com, linux-cifs@vger.kernel.org Subject: Re: [PATCH] ksmbd: fix slab-out-of-bounds read in smb2_handle_negotiate Message-ID: <20230517110505.GB20467@google.com> References: <20230517095951.3476020-1-h3xrabbit@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230517095951.3476020-1-h3xrabbit@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org On (23/05/17 09:59), HexRabbit wrote: > [ 3350.990282] BUG: KASAN: slab-out-of-bounds in smb2_handle_negotiate+0x35d7/0x3e60 > [ 3350.990282] Read of size 2 at addr ffff88810ad61346 by task kworker/5:0/276 > [ 3351.000406] Workqueue: ksmbd-io handle_ksmbd_work > [ 3351.003499] Call Trace: > [ 3351.006473] > [ 3351.006473] dump_stack_lvl+0x8d/0xe0 > [ 3351.006473] print_report+0xcc/0x620 > [ 3351.006473] kasan_report+0x92/0xc0 > [ 3351.006473] smb2_handle_negotiate+0x35d7/0x3e60 > [ 3351.014760] ksmbd_smb_negotiate_common+0x7a7/0xf00 > [ 3351.014760] handle_ksmbd_work+0x3f7/0x12d0 > [ 3351.014760] process_one_work+0xa85/0x1780 [..] > - if (req->DialectCount == 0) { > - pr_err("malformed packet\n"); > + smb2_buf_len = get_rfc1002_len(work->request_buf); > + smb2_neg_size = offsetof(struct smb2_negotiate_req, Dialects); > + if (smb2_neg_size > smb2_buf_len) { > rsp->hdr.Status = STATUS_INVALID_PARAMETER; > rc = -EINVAL; > goto err_out; > } > > - smb2_buf_len = get_rfc1002_len(work->request_buf); > - smb2_neg_size = offsetof(struct smb2_negotiate_req, Dialects); > - if (smb2_neg_size > smb2_buf_len) { > + if (req->DialectCount == 0) { > + pr_err("malformed packet\n"); > rsp->hdr.Status = STATUS_INVALID_PARAMETER; > rc = -EINVAL; > goto err_out; May I please ask where out-of-bounds access happens and how does `smb2_neg_size > smb2_buf_len` fix it?