From patchwork Thu Sep 23 03:48:55 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Namjae Jeon X-Patchwork-Id: 1531543 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-cifs-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4HFLkz5yGPz9sW8 for ; Thu, 23 Sep 2021 13:49:31 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239076AbhIWDvB (ORCPT ); Wed, 22 Sep 2021 23:51:01 -0400 Received: from mail-pf1-f177.google.com ([209.85.210.177]:45673 "EHLO mail-pf1-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239167AbhIWDuv (ORCPT ); Wed, 22 Sep 2021 23:50:51 -0400 Received: by mail-pf1-f177.google.com with SMTP id w19so4461678pfn.12 for ; Wed, 22 Sep 2021 20:49:20 -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=k3LF3S9KUuAMs7lh3ps8Cs9i+uGzMIc/N2BaEiakiZ0=; b=MctcM3eeBaQ0fQxPbfUp7iMcnGm3ffg4omuOeFc6t3HQO7+9d2GmyT4yx4S06BA67f 256Kirc61r2Jr0DBl0ntUeIH6tBtig0I+fCMBGJ0aRuYA6MSJs3pnDlQYAGmialY/mjr PAguAnqvdEvfoM9sVhWnw5MEhEGeMkcTQhr9C7sIbuUhhGnIb5HmWVoXj72S6798IVai es47Mfq4M4a1PIrbvliSK6ITYL8rN5q768GBaqzBExDEelf6uC9YJpeEa4VvkaGcr3WN L+OJzEu3KNyNfMPqn7xdq3N5sP89+CUmw6KVVs6nPCtVk+RqfJ9vL843wXccQdvc8qmW BQEw== X-Gm-Message-State: AOAM5322PgMgksq+eZ3ZNqf4Kh6sfD3e1CXDojccNYlsyD74SYrTadp0 FeZO0S/MkLb/RsVpewFNkKBSo9YlPzFYJA== X-Google-Smtp-Source: ABdhPJwXsl0zTrvQN/83nAliGRbZiTZsad2yA1bdQ0/LVk5/JLLY/1Q4DLux6VIcB7cuHH2W3c47Pg== X-Received: by 2002:a63:788d:: with SMTP id t135mr2232561pgc.116.1632368959859; Wed, 22 Sep 2021 20:49:19 -0700 (PDT) Received: from localhost.localdomain ([61.74.27.164]) by smtp.gmail.com with ESMTPSA id y204sm3045883pfc.100.2021.09.22.20.49.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 22 Sep 2021 20:49:19 -0700 (PDT) From: Namjae Jeon To: linux-cifs@vger.kernel.org Cc: Namjae Jeon , Tom Talpey , Ronnie Sahlberg , =?utf-8?q?Ralph_B=C3=B6hme?= , Steve French Subject: [PATCH v3] ksmbd: add validation in smb2 negotiate Date: Thu, 23 Sep 2021 12:48:55 +0900 Message-Id: <20210923034855.612832-3-linkinjeon@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210923034855.612832-1-linkinjeon@kernel.org> References: <20210923034855.612832-1-linkinjeon@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org This patch add validation to check request buffer check in smb2 negotiate. Cc: Tom Talpey Cc: Ronnie Sahlberg Cc: Ralph Böhme Cc: Steve French Signed-off-by: Namjae Jeon --- v3: - fix integer(nego_ctxt_off) overflow issue. - change data type of variables to unsigned. fs/ksmbd/smb2pdu.c | 40 ++++++++++++++++++++++++++++++++++++++++ fs/ksmbd/smb_common.c | 22 ++++++++++++++++++++-- 2 files changed, 60 insertions(+), 2 deletions(-) diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index 301558a04298..2f9719a3f089 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -1080,6 +1080,7 @@ int smb2_handle_negotiate(struct ksmbd_work *work) struct smb2_negotiate_req *req = work->request_buf; struct smb2_negotiate_rsp *rsp = work->response_buf; int rc = 0; + unsigned int smb2_buf_len, smb2_neg_size; __le32 status; ksmbd_debug(SMB, "Received negotiate request\n"); @@ -1097,6 +1098,45 @@ int smb2_handle_negotiate(struct ksmbd_work *work) goto err_out; } + smb2_buf_len = get_rfc1002_len(work->request_buf); + smb2_neg_size = offsetof(struct smb2_negotiate_req, Dialects) - 4; + if (conn->dialect == SMB311_PROT_ID) { + unsigned int nego_ctxt_off = le32_to_cpu(req->NegotiateContextOffset); + unsigned int nego_ctxt_count = le16_to_cpu(req->NegotiateContextCount); + + if (smb2_buf_len < (u64)nego_ctxt_off + nego_ctxt_count) { + rsp->hdr.Status = STATUS_INVALID_PARAMETER; + rc = -EINVAL; + goto err_out; + } + + if (smb2_neg_size > nego_ctxt_off) { + rsp->hdr.Status = STATUS_INVALID_PARAMETER; + rc = -EINVAL; + goto err_out; + } + + if (smb2_neg_size + le16_to_cpu(req->DialectCount) * sizeof(__le16) > + nego_ctxt_off) { + rsp->hdr.Status = STATUS_INVALID_PARAMETER; + rc = -EINVAL; + goto err_out; + } + } else { + if (smb2_neg_size > smb2_buf_len) { + rsp->hdr.Status = STATUS_INVALID_PARAMETER; + rc = -EINVAL; + goto err_out; + } + + if (smb2_neg_size + le16_to_cpu(req->DialectCount) * sizeof(__le16) > + smb2_buf_len) { + rsp->hdr.Status = STATUS_INVALID_PARAMETER; + rc = -EINVAL; + goto err_out; + } + } + conn->cli_cap = le32_to_cpu(req->Capabilities); switch (conn->dialect) { case SMB311_PROT_ID: diff --git a/fs/ksmbd/smb_common.c b/fs/ksmbd/smb_common.c index ebc835ab414c..02fe2a06dda9 100644 --- a/fs/ksmbd/smb_common.c +++ b/fs/ksmbd/smb_common.c @@ -235,13 +235,22 @@ int ksmbd_lookup_dialect_by_id(__le16 *cli_dialects, __le16 dialects_count) static int ksmbd_negotiate_smb_dialect(void *buf) { - __le32 proto; + int smb_buf_length = get_rfc1002_len(buf); + __le32 proto = ((struct smb2_hdr *)buf)->ProtocolId; - proto = ((struct smb2_hdr *)buf)->ProtocolId; if (proto == SMB2_PROTO_NUMBER) { struct smb2_negotiate_req *req; + int smb2_neg_size = + offsetof(struct smb2_negotiate_req, Dialects) - 4; req = (struct smb2_negotiate_req *)buf; + if (smb2_neg_size > smb_buf_length) + goto err_out; + + if (smb2_neg_size + le16_to_cpu(req->DialectCount) * sizeof(__le16) > + smb_buf_length) + goto err_out; + return ksmbd_lookup_dialect_by_id(req->Dialects, req->DialectCount); } @@ -251,10 +260,19 @@ static int ksmbd_negotiate_smb_dialect(void *buf) struct smb_negotiate_req *req; req = (struct smb_negotiate_req *)buf; + if (le16_to_cpu(req->ByteCount) < 2) + goto err_out; + + if (offsetof(struct smb_negotiate_req, DialectsArray) - 4 + + le16_to_cpu(req->ByteCount) > smb_buf_length) { + goto err_out; + } + return ksmbd_lookup_dialect_by_name(req->DialectsArray, req->ByteCount); } +err_out: return BAD_PROT_ID; }