From patchwork Sun Sep 26 13:55:43 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Namjae Jeon X-Patchwork-Id: 12518293 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 35198C433F5 for ; Sun, 26 Sep 2021 14:12:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1D11560FC2 for ; Sun, 26 Sep 2021 14:12:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231838AbhIZOOL (ORCPT ); Sun, 26 Sep 2021 10:14:11 -0400 Received: from mail-pg1-f182.google.com ([209.85.215.182]:35458 "EHLO mail-pg1-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231835AbhIZOOL (ORCPT ); Sun, 26 Sep 2021 10:14:11 -0400 Received: by mail-pg1-f182.google.com with SMTP id e7so15221984pgk.2 for ; Sun, 26 Sep 2021 07:12:35 -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=BTcI0heHQU8Ojlx3N/Tu2VRkE3CKcNibHsGOwViSlxY=; b=xesfKFhb+PAtr14v8InXvZ+5WB8fNq1ZxICNKUOwWIxImNHaP9DP7po+LyIcD71I6+ yiLv9z+SROxNSkPYLEMm47NshnR/kosD2nVKmCd7uT+LCS9r3AvX0HyO7A+9K3O/zlfG /Lw25AtrtBzL38K+qwH9j6unh0e6Tw4z9YVNK5OHvp16+40mQKlGRIDqn8oj3dXhfIO3 8MYOR35QntUhjrgTaTJz4Ydo1LozH7RjeJ1CtBQnSt5Fh/aDIZ2RbS1QYPsV88L1RA/m 73xKlxEJVIY5NNKVgx9Tuiuzv9tul4Ma4xheBedqLTQbjWmeHugevC7S0v3DeqFHchuZ 5yWA== X-Gm-Message-State: AOAM530DS8isWa1BJ/LtYJNpQZoLWuK8zzeqH1pr6b11JhZ/wFjVmPuy CQZAKP5fFeiR9tu2t5c4GpXLIyRvP0QMCQ== X-Google-Smtp-Source: ABdhPJxS4fdp+d9ohv2WJTd7/XMNBCrVzwPfBzRdg/yCeCFGZ+/2HuRDZqmuMbhNxeieJ1DmURl0iw== X-Received: by 2002:a63:6e41:: with SMTP id j62mr12482078pgc.120.1632665554762; Sun, 26 Sep 2021 07:12:34 -0700 (PDT) Received: from localhost.localdomain ([61.74.27.164]) by smtp.gmail.com with ESMTPSA id g3sm16521742pgf.1.2021.09.26.07.12.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 26 Sep 2021 07:12:34 -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 , Hyunchul Lee , Sergey Senozhatsky Subject: [PATCH v3 5/5] ksmbd: add validation in smb2 negotiate Date: Sun, 26 Sep 2021 22:55:43 +0900 Message-Id: <20210926135543.119127-6-linkinjeon@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210926135543.119127-1-linkinjeon@kernel.org> References: <20210926135543.119127-1-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 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 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 dca979d2ef52..6e93ff0f164e 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 (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 > 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: @@ -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 36fd9695fbc5..5d8e32041c15 100644 --- a/fs/ksmbd/smb_common.c +++ b/fs/ksmbd/smb_common.c @@ -162,10 +162,12 @@ 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; } @@ -180,7 +182,9 @@ 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)) { @@ -228,13 +232,22 @@ 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); } @@ -244,10 +257,19 @@ 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; }