From patchwork Fri Oct 1 12:04:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Ralph Boehme X-Patchwork-Id: 12530513 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A2502C433F5 for ; Fri, 1 Oct 2021 12:25:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 883D161A55 for ; Fri, 1 Oct 2021 12:25:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354185AbhJAM1F (ORCPT ); Fri, 1 Oct 2021 08:27:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53244 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1353397AbhJAM1E (ORCPT ); Fri, 1 Oct 2021 08:27:04 -0400 Received: from hr2.samba.org (hr2.samba.org [IPv6:2a01:4f8:192:486::2:0]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9CE95C061775 for ; Fri, 1 Oct 2021 05:25:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=samba.org; s=42; h=Message-Id:Date:Cc:To:From; bh=GJ6/GkDvZZxumGF9X6kh0wVdtvWV67L6QDPsqqQ8/3s=; b=pByUBAVkV0xjoDTGozXgAFdbEy RLfev4+Ys972YUWif7UjJrae9FmVBsqTjTk45WOHkaSqByvGLbshPovl/2AwxIocJocPg1Unm4XKL eDJZ+G67WWBLmbz4LoBFcX4Lu2ndLBol7JnId5v6AojHYf8+TSFq2ARfuahxET9a+8Wx8bMdPRKWC g9j5pS6d+yCP27XJwllTIJ9HT66grjYHA2nHBNoIGyLql4saqAS6OhCwOzObTu5wCaN7Ubcg50S4M HGXwnqm4UJ5r4HXVt9W91NPEt4cjwzQBG9gAy8hm8S7g3v3xwtP565NHwCep/78KAOBjUa0tgGI6n bDluCsVU39oeevF7C0cq7Ydu8tH8EQAltOCgjpKy7wHqcyeptv5t6ujGTnKzYnv0kYu7muSNMrHDV dkbbs96ZiaZd+oKGGoi/R0TkMNxkrUf/FFacBBUWfBvNZ6XK17xKtAq8oIXhnx3s0xWSRQhlfU67k ebaPgKm8snuAs7N4DUL16047; Received: from [127.0.0.2] (localhost [127.0.0.1]) by hr2.samba.org with esmtpsa (TLS1.3:ECDHE_SECP256R1__ECDSA_SECP256R1_SHA256__CHACHA20_POLY1305:256) (Exim) id 1mWHIO-0013Z3-55; Fri, 01 Oct 2021 12:05:44 +0000 From: Ralph Boehme To: linux-cifs@vger.kernel.org Cc: Namjae Jeon , Tom Talpey , Ronnie Sahlberg , =?utf-8?q?Ralph_B=C3=B6hme?= , Steve French , Hyunchul Lee , Sergey Senozhatsky Subject: [PATCH v5 06/20] ksmbd: add validation in smb2 negotiate Date: Fri, 1 Oct 2021 14:04:07 +0200 Message-Id: <20211001120421.327245-7-slow@samba.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211001120421.327245-1-slow@samba.org> References: <20211001120421.327245-1-slow@samba.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org From: Namjae Jeon This patch add validation to check request buffer check in smb2 negotiate and fix null pointer deferencing oops in smb3_preauth_hash_rsp() that found from manual test. Cc: Tom Talpey Cc: Ronnie Sahlberg Cc: Ralph Böhme Cc: Steve French Cc: Hyunchul Lee Cc: Sergey Senozhatsky Reviewed-by: Ralph Boehme Signed-off-by: Namjae Jeon --- fs/ksmbd/smb2pdu.c | 42 +++++++++++++++++++++++++++++++++++++++++- fs/ksmbd/smb_common.c | 32 +++++++++++++++++++++++++++----- 2 files changed, 68 insertions(+), 6 deletions(-) diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index c434390ffcae..0b0ab3297e05 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -1067,6 +1067,7 @@ 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"); @@ -1084,6 +1085,44 @@ 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 (smb2_neg_size > smb2_buf_len) { + rsp->hdr.Status = STATUS_INVALID_PARAMETER; + rc = -EINVAL; + goto err_out; + } + + if (conn->dialect == SMB311_PROT_ID) { + unsigned int nego_ctxt_off = le32_to_cpu(req->NegotiateContextOffset); + + if (smb2_buf_len < nego_ctxt_off) { + 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 + 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: @@ -8301,7 +8340,8 @@ void smb3_preauth_hash_rsp(struct ksmbd_work *work) WORK_BUFFERS(work, req, rsp); - if (le16_to_cpu(req->Command) == SMB2_NEGOTIATE_HE) + if (le16_to_cpu(req->Command) == SMB2_NEGOTIATE_HE && + conn->preauth_info) ksmbd_gen_preauth_integrity_hash(conn, (char *)rsp, conn->preauth_info->Preauth_HashValue); diff --git a/fs/ksmbd/smb_common.c b/fs/ksmbd/smb_common.c index 20bd5b8e3c0a..b6c4c7e960fa 100644 --- a/fs/ksmbd/smb_common.c +++ b/fs/ksmbd/smb_common.c @@ -168,10 +168,12 @@ static bool supported_protocol(int idx) idx <= server_conf.max_protocol); } -static char *next_dialect(char *dialect, int *next_off) +static char *next_dialect(char *dialect, int *next_off, int bcount) { dialect = dialect + *next_off; - *next_off = strlen(dialect); + *next_off = strnlen(dialect, bcount); + if (dialect[*next_off] != '\0') + return NULL; return dialect; } @@ -186,7 +188,9 @@ static int ksmbd_lookup_dialect_by_name(char *cli_dialects, __le16 byte_count) dialect = cli_dialects; bcount = le16_to_cpu(byte_count); do { - dialect = next_dialect(dialect, &next); + dialect = next_dialect(dialect, &next, bcount); + if (!dialect) + break; ksmbd_debug(SMB, "client requested dialect %s\n", dialect); if (!strcmp(dialect, smb1_protos[i].name)) { @@ -234,13 +238,22 @@ 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); } @@ -250,10 +263,19 @@ 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; }