From patchwork Fri Oct 1 12:04:08 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ralph Boehme X-Patchwork-Id: 12530521 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 F3A23C433F5 for ; Fri, 1 Oct 2021 12:25:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DCC2961A55 for ; Fri, 1 Oct 2021 12:25:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353397AbhJAM1T (ORCPT ); Fri, 1 Oct 2021 08:27:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53300 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354362AbhJAM1P (ORCPT ); Fri, 1 Oct 2021 08:27:15 -0400 Received: from hr2.samba.org (hr2.samba.org [IPv6:2a01:4f8:192:486::2:0]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2296FC061775 for ; Fri, 1 Oct 2021 05:25:30 -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=4sgNGeiX6lIjDAIyfrNU1nThIZ+c07EIJLYzoomm29s=; b=UnmrWgP3st7iFiMcPNp5K7Z6Q5 Dp1kJnfb3WGBSyQYr0KVfPs1tM+fLvp1IhWUQGom58g7V92P0h3ddQukY8Z331zptj40DDnSD/IJ0 v5lRcFWhI9zby3bjdrmB8OQFbWFQkVfBpWbx2l7rfClJmmjg4qyIcdFimyVITVpPTsbchspPSuT27 c+BqUSZ1SoNysgckReWvDNO0Dm4bP3R+XeGclJbDrtWHNLFmFrkwN33nEGPgr4FQX4tnFgXNr7RBT /G8C39+pKrp6QNQMb+H+dinrlOd82dgjAZaP83RnWAJ1UWCLefTtkrjuGdJy9rr1q2k9TMG0e2I8y Zj8LQLfrNFfOZv/ppYY64Z10V3pyRZJ5ZUXBYQYHcoHo0yZKMVUeLmr2V9vVcGDJpo9zae4Ya51dn R5FmNNdCmHilWegztngR4F1s/K3gw0rWChrpCE1V62Fzvo2LYQqEs/8HccxLEMq1mUqujnVhKloDC FC7JtWuXrZJO1YOS6ZpNySQl; 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-MX; Fri, 01 Oct 2021 12:05:44 +0000 From: Ralph Boehme To: linux-cifs@vger.kernel.org Cc: Hyunchul Lee , Ronnie Sahlberg , Steve French , Ralph Boehme , Namjae Jeon Subject: [PATCH v5 07/20] ksmbd: add buffer validation for SMB2_CREATE_CONTEXT Date: Fri, 1 Oct 2021 14:04:08 +0200 Message-Id: <20211001120421.327245-8-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: Hyunchul Lee Add buffer validation for SMB2_CREATE_CONTEXT. Cc: Ronnie Sahlberg Cc: Steve French Reviewed-by: Ralph Boehme Signed-off-by: Hyunchul Lee Signed-off-by: Namjae Jeon --- fs/ksmbd/oplock.c | 41 +++++++++++++++++++++++++++++++---------- fs/ksmbd/smb2pdu.c | 25 ++++++++++++++++++++++++- fs/ksmbd/smbacl.c | 21 +++++++++++++++++++-- 3 files changed, 74 insertions(+), 13 deletions(-) diff --git a/fs/ksmbd/oplock.c b/fs/ksmbd/oplock.c index 16b6236d1bd2..f9dae6ef2115 100644 --- a/fs/ksmbd/oplock.c +++ b/fs/ksmbd/oplock.c @@ -1451,26 +1451,47 @@ struct lease_ctx_info *parse_lease_state(void *open_req) */ struct create_context *smb2_find_context_vals(void *open_req, const char *tag) { - char *data_offset; struct create_context *cc; unsigned int next = 0; char *name; struct smb2_create_req *req = (struct smb2_create_req *)open_req; + unsigned int remain_len, name_off, name_len, value_off, value_len, + cc_len; - data_offset = (char *)req + 4 + le32_to_cpu(req->CreateContextsOffset); - cc = (struct create_context *)data_offset; + /* + * CreateContextsOffset and CreateContextsLength are guaranteed to + * be valid because of ksmbd_smb2_check_message(). + */ + cc = (struct create_context *)((char *)req + 4 + + le32_to_cpu(req->CreateContextsOffset)); + remain_len = le32_to_cpu(req->CreateContextsLength); do { - int val; - cc = (struct create_context *)((char *)cc + next); - name = le16_to_cpu(cc->NameOffset) + (char *)cc; - val = le16_to_cpu(cc->NameLength); - if (val < 4) + if (remain_len < offsetof(struct create_context, Buffer)) return ERR_PTR(-EINVAL); - if (memcmp(name, tag, val) == 0) - return cc; next = le32_to_cpu(cc->Next); + name_off = le16_to_cpu(cc->NameOffset); + name_len = le16_to_cpu(cc->NameLength); + value_off = le16_to_cpu(cc->DataOffset); + value_len = le32_to_cpu(cc->DataLength); + cc_len = next ? next : remain_len; + + if ((next & 0x7) != 0 || + next > remain_len || + name_off != offsetof(struct create_context, Buffer) || + name_len < 4 || + name_off + name_len > cc_len || + (value_off & 0x7) != 0 || + (value_off && (value_off < name_off + name_len)) || + ((u64)value_off + value_len > cc_len)) + return ERR_PTR(-EINVAL); + + name = (char *)cc + name_off; + if (memcmp(name, tag, name_len) == 0) + return cc; + + remain_len -= next; } while (next != 0); return NULL; diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index 0b0ab3297e05..e40bcc86f3b3 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -2427,6 +2427,10 @@ static int smb2_create_sd_buffer(struct ksmbd_work *work, ksmbd_debug(SMB, "Set ACLs using SMB2_CREATE_SD_BUFFER context\n"); sd_buf = (struct create_sd_buf_req *)context; + if (le16_to_cpu(context->DataOffset) + + le32_to_cpu(context->DataLength) < + sizeof(struct create_sd_buf_req)) + return -EINVAL; return set_info_sec(work->conn, work->tcon, path, &sd_buf->ntsd, le32_to_cpu(sd_buf->ccontext.DataLength), true); } @@ -2621,6 +2625,12 @@ int smb2_open(struct ksmbd_work *work) goto err_out1; } else if (context) { ea_buf = (struct create_ea_buf_req *)context; + if (le16_to_cpu(context->DataOffset) + + le32_to_cpu(context->DataLength) < + sizeof(struct create_ea_buf_req)) { + rc = -EINVAL; + goto err_out1; + } if (req->CreateOptions & FILE_NO_EA_KNOWLEDGE_LE) { rsp->hdr.Status = STATUS_ACCESS_DENIED; rc = -EACCES; @@ -2659,6 +2669,12 @@ int smb2_open(struct ksmbd_work *work) } else if (context) { struct create_posix *posix = (struct create_posix *)context; + if (le16_to_cpu(context->DataOffset) + + le32_to_cpu(context->DataLength) < + sizeof(struct create_posix)) { + rc = -EINVAL; + goto err_out1; + } ksmbd_debug(SMB, "get posix context\n"); posix_mode = le32_to_cpu(posix->Mode); @@ -3049,9 +3065,16 @@ int smb2_open(struct ksmbd_work *work) rc = PTR_ERR(az_req); goto err_out; } else if (az_req) { - loff_t alloc_size = le64_to_cpu(az_req->AllocationSize); + loff_t alloc_size; int err; + if (le16_to_cpu(az_req->ccontext.DataOffset) + + le32_to_cpu(az_req->ccontext.DataLength) < + sizeof(struct create_alloc_size_req)) { + rc = -EINVAL; + goto err_out; + } + alloc_size = le64_to_cpu(az_req->AllocationSize); ksmbd_debug(SMB, "request smb2 create allocate size : %llu\n", alloc_size); diff --git a/fs/ksmbd/smbacl.c b/fs/ksmbd/smbacl.c index 0a95cdec8c80..bd792db32623 100644 --- a/fs/ksmbd/smbacl.c +++ b/fs/ksmbd/smbacl.c @@ -380,7 +380,7 @@ static void parse_dacl(struct user_namespace *user_ns, { int i, ret; int num_aces = 0; - int acl_size; + unsigned int acl_size; char *acl_base; struct smb_ace **ppace; struct posix_acl_entry *cf_pace, *cf_pdace; @@ -392,7 +392,7 @@ static void parse_dacl(struct user_namespace *user_ns, return; /* validate that we do not go past end of acl */ - if (end_of_acl <= (char *)pdacl || + if (end_of_acl < (char *)pdacl + sizeof(struct smb_acl) || end_of_acl < (char *)pdacl + le16_to_cpu(pdacl->size)) { pr_err("ACL too small to parse DACL\n"); return; @@ -431,8 +431,22 @@ static void parse_dacl(struct user_namespace *user_ns, * user/group/other have no permissions */ for (i = 0; i < num_aces; ++i) { + if (end_of_acl - acl_base < acl_size) + break; + ppace[i] = (struct smb_ace *)(acl_base + acl_size); acl_base = (char *)ppace[i]; + acl_size = offsetof(struct smb_ace, sid) + + offsetof(struct smb_sid, sub_auth); + + if (end_of_acl - acl_base < acl_size || + ppace[i]->sid.num_subauth > SID_MAX_SUB_AUTHORITIES || + (end_of_acl - acl_base < + acl_size + sizeof(__le32) * ppace[i]->sid.num_subauth) || + (le16_to_cpu(ppace[i]->size) < + acl_size + sizeof(__le32) * ppace[i]->sid.num_subauth)) + break; + acl_size = le16_to_cpu(ppace[i]->size); ppace[i]->access_req = smb_map_generic_desired_access(ppace[i]->access_req); @@ -807,6 +821,9 @@ int parse_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd, if (!pntsd) return -EIO; + if (acl_len < sizeof(struct smb_ntsd)) + return -EINVAL; + owner_sid_ptr = (struct smb_sid *)((char *)pntsd + le32_to_cpu(pntsd->osidoffset)); group_sid_ptr = (struct smb_sid *)((char *)pntsd +