| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * Copyright (C) 2016 Namjae Jeon <linkinjeon@kernel.org> |
| * Copyright (C) 2018 Samsung Electronics Co., Ltd. |
| */ |
| |
| #include "glob.h" |
| #include "nterr.h" |
| #include "smb_common.h" |
| #include "smbstatus.h" |
| #include "mgmt/user_session.h" |
| #include "connection.h" |
| |
| static int check_smb2_hdr(struct smb2_hdr *hdr) |
| { |
| /* |
| * Make sure that this really is an SMB, that it is a response. |
| */ |
| if (hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR) |
| return 1; |
| return 0; |
| } |
| |
| /* |
| * The following table defines the expected "StructureSize" of SMB2 requests |
| * in order by SMB2 command. This is similar to "wct" in SMB/CIFS requests. |
| * |
| * Note that commands are defined in smb2pdu.h in le16 but the array below is |
| * indexed by command in host byte order |
| */ |
| static const __le16 smb2_req_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = { |
| /* SMB2_NEGOTIATE */ cpu_to_le16(36), |
| /* SMB2_SESSION_SETUP */ cpu_to_le16(25), |
| /* SMB2_LOGOFF */ cpu_to_le16(4), |
| /* SMB2_TREE_CONNECT */ cpu_to_le16(9), |
| /* SMB2_TREE_DISCONNECT */ cpu_to_le16(4), |
| /* SMB2_CREATE */ cpu_to_le16(57), |
| /* SMB2_CLOSE */ cpu_to_le16(24), |
| /* SMB2_FLUSH */ cpu_to_le16(24), |
| /* SMB2_READ */ cpu_to_le16(49), |
| /* SMB2_WRITE */ cpu_to_le16(49), |
| /* SMB2_LOCK */ cpu_to_le16(48), |
| /* SMB2_IOCTL */ cpu_to_le16(57), |
| /* SMB2_CANCEL */ cpu_to_le16(4), |
| /* SMB2_ECHO */ cpu_to_le16(4), |
| /* SMB2_QUERY_DIRECTORY */ cpu_to_le16(33), |
| /* SMB2_CHANGE_NOTIFY */ cpu_to_le16(32), |
| /* SMB2_QUERY_INFO */ cpu_to_le16(41), |
| /* SMB2_SET_INFO */ cpu_to_le16(33), |
| /* use 44 for lease break */ |
| /* SMB2_OPLOCK_BREAK */ cpu_to_le16(36) |
| }; |
| |
| /* |
| * The size of the variable area depends on the offset and length fields |
| * located in different fields for various SMB2 requests. SMB2 requests |
| * with no variable length info, show an offset of zero for the offset field. |
| */ |
| static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = { |
| /* SMB2_NEGOTIATE */ true, |
| /* SMB2_SESSION_SETUP */ true, |
| /* SMB2_LOGOFF */ false, |
| /* SMB2_TREE_CONNECT */ true, |
| /* SMB2_TREE_DISCONNECT */ false, |
| /* SMB2_CREATE */ true, |
| /* SMB2_CLOSE */ false, |
| /* SMB2_FLUSH */ false, |
| /* SMB2_READ */ true, |
| /* SMB2_WRITE */ true, |
| /* SMB2_LOCK */ true, |
| /* SMB2_IOCTL */ true, |
| /* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */ |
| /* SMB2_ECHO */ false, |
| /* SMB2_QUERY_DIRECTORY */ true, |
| /* SMB2_CHANGE_NOTIFY */ false, |
| /* SMB2_QUERY_INFO */ true, |
| /* SMB2_SET_INFO */ true, |
| /* SMB2_OPLOCK_BREAK */ false |
| }; |
| |
| /* |
| * Set length of the data area and the offset to arguments. |
| * if they are invalid, return error. |
| */ |
| static int smb2_get_data_area_len(unsigned int *off, unsigned int *len, |
| struct smb2_hdr *hdr) |
| { |
| int ret = 0; |
| |
| *off = 0; |
| *len = 0; |
| |
| /* |
| * Following commands have data areas so we have to get the location |
| * of the data buffer offset and data buffer length for the particular |
| * command. |
| */ |
| switch (hdr->Command) { |
| case SMB2_SESSION_SETUP: |
| *off = le16_to_cpu(((struct smb2_sess_setup_req *)hdr)->SecurityBufferOffset); |
| *len = le16_to_cpu(((struct smb2_sess_setup_req *)hdr)->SecurityBufferLength); |
| break; |
| case SMB2_TREE_CONNECT: |
| *off = le16_to_cpu(((struct smb2_tree_connect_req *)hdr)->PathOffset); |
| *len = le16_to_cpu(((struct smb2_tree_connect_req *)hdr)->PathLength); |
| break; |
| case SMB2_CREATE: |
| { |
| unsigned short int name_off = |
| le16_to_cpu(((struct smb2_create_req *)hdr)->NameOffset); |
| unsigned short int name_len = |
| le16_to_cpu(((struct smb2_create_req *)hdr)->NameLength); |
| |
| if (((struct smb2_create_req *)hdr)->CreateContextsLength) { |
| *off = le32_to_cpu(((struct smb2_create_req *) |
| hdr)->CreateContextsOffset); |
| *len = le32_to_cpu(((struct smb2_create_req *) |
| hdr)->CreateContextsLength); |
| if (!name_len) |
| break; |
| |
| if (name_off + name_len < (u64)*off + *len) |
| break; |
| } |
| |
| *off = name_off; |
| *len = name_len; |
| break; |
| } |
| case SMB2_QUERY_INFO: |
| *off = le16_to_cpu(((struct smb2_query_info_req *)hdr)->InputBufferOffset); |
| *len = le32_to_cpu(((struct smb2_query_info_req *)hdr)->InputBufferLength); |
| break; |
| case SMB2_SET_INFO: |
| *off = le16_to_cpu(((struct smb2_set_info_req *)hdr)->BufferOffset); |
| *len = le32_to_cpu(((struct smb2_set_info_req *)hdr)->BufferLength); |
| break; |
| case SMB2_READ: |
| *off = le16_to_cpu(((struct smb2_read_req *)hdr)->ReadChannelInfoOffset); |
| *len = le16_to_cpu(((struct smb2_read_req *)hdr)->ReadChannelInfoLength); |
| break; |
| case SMB2_WRITE: |
| if (((struct smb2_write_req *)hdr)->DataOffset || |
| ((struct smb2_write_req *)hdr)->Length) { |
| *off = max_t(unsigned int, |
| le16_to_cpu(((struct smb2_write_req *)hdr)->DataOffset), |
| offsetof(struct smb2_write_req, Buffer)); |
| *len = le32_to_cpu(((struct smb2_write_req *)hdr)->Length); |
| break; |
| } |
| |
| *off = le16_to_cpu(((struct smb2_write_req *)hdr)->WriteChannelInfoOffset); |
| *len = le16_to_cpu(((struct smb2_write_req *)hdr)->WriteChannelInfoLength); |
| break; |
| case SMB2_QUERY_DIRECTORY: |
| *off = le16_to_cpu(((struct smb2_query_directory_req *)hdr)->FileNameOffset); |
| *len = le16_to_cpu(((struct smb2_query_directory_req *)hdr)->FileNameLength); |
| break; |
| case SMB2_LOCK: |
| { |
| unsigned short lock_count; |
| |
| lock_count = le16_to_cpu(((struct smb2_lock_req *)hdr)->LockCount); |
| if (lock_count > 0) { |
| *off = offsetof(struct smb2_lock_req, locks); |
| *len = sizeof(struct smb2_lock_element) * lock_count; |
| } |
| break; |
| } |
| case SMB2_IOCTL: |
| *off = le32_to_cpu(((struct smb2_ioctl_req *)hdr)->InputOffset); |
| *len = le32_to_cpu(((struct smb2_ioctl_req *)hdr)->InputCount); |
| break; |
| default: |
| ksmbd_debug(SMB, "no length check for command\n"); |
| break; |
| } |
| |
| if (*off > 4096) { |
| ksmbd_debug(SMB, "offset %d too large\n", *off); |
| ret = -EINVAL; |
| } else if ((u64)*off + *len > MAX_STREAM_PROT_LEN) { |
| ksmbd_debug(SMB, "Request is larger than maximum stream protocol length(%u): %llu\n", |
| MAX_STREAM_PROT_LEN, (u64)*off + *len); |
| ret = -EINVAL; |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * Calculate the size of the SMB message based on the fixed header |
| * portion, the number of word parameters and the data portion of the message. |
| */ |
| static int smb2_calc_size(void *buf, unsigned int *len) |
| { |
| struct smb2_pdu *pdu = (struct smb2_pdu *)buf; |
| struct smb2_hdr *hdr = &pdu->hdr; |
| unsigned int offset; /* the offset from the beginning of SMB to data area */ |
| unsigned int data_length; /* the length of the variable length data area */ |
| int ret; |
| |
| /* Structure Size has already been checked to make sure it is 64 */ |
| *len = le16_to_cpu(hdr->StructureSize); |
| |
| /* |
| * StructureSize2, ie length of fixed parameter area has already |
| * been checked to make sure it is the correct length. |
| */ |
| *len += le16_to_cpu(pdu->StructureSize2); |
| /* |
| * StructureSize2 of smb2_lock pdu is set to 48, indicating |
| * the size of smb2 lock request with single smb2_lock_element |
| * regardless of number of locks. Subtract single |
| * smb2_lock_element for correct buffer size check. |
| */ |
| if (hdr->Command == SMB2_LOCK) |
| *len -= sizeof(struct smb2_lock_element); |
| |
| if (has_smb2_data_area[le16_to_cpu(hdr->Command)] == false) |
| goto calc_size_exit; |
| |
| ret = smb2_get_data_area_len(&offset, &data_length, hdr); |
| if (ret) |
| return ret; |
| ksmbd_debug(SMB, "SMB2 data length %u offset %u\n", data_length, |
| offset); |
| |
| if (data_length > 0) { |
| /* |
| * Check to make sure that data area begins after fixed area, |
| * Note that last byte of the fixed area is part of data area |
| * for some commands, typically those with odd StructureSize, |
| * so we must add one to the calculation. |
| */ |
| if (offset + 1 < *len) { |
| ksmbd_debug(SMB, |
| "data area offset %d overlaps SMB2 header %u\n", |
| offset + 1, *len); |
| return -EINVAL; |
| } |
| |
| *len = offset + data_length; |
| } |
| |
| calc_size_exit: |
| ksmbd_debug(SMB, "SMB2 len %u\n", *len); |
| return 0; |
| } |
| |
| static inline int smb2_query_info_req_len(struct smb2_query_info_req *h) |
| { |
| return le32_to_cpu(h->InputBufferLength) + |
| le32_to_cpu(h->OutputBufferLength); |
| } |
| |
| static inline int smb2_set_info_req_len(struct smb2_set_info_req *h) |
| { |
| return le32_to_cpu(h->BufferLength); |
| } |
| |
| static inline int smb2_read_req_len(struct smb2_read_req *h) |
| { |
| return le32_to_cpu(h->Length); |
| } |
| |
| static inline int smb2_write_req_len(struct smb2_write_req *h) |
| { |
| return le32_to_cpu(h->Length); |
| } |
| |
| static inline int smb2_query_dir_req_len(struct smb2_query_directory_req *h) |
| { |
| return le32_to_cpu(h->OutputBufferLength); |
| } |
| |
| static inline int smb2_ioctl_req_len(struct smb2_ioctl_req *h) |
| { |
| return le32_to_cpu(h->InputCount) + |
| le32_to_cpu(h->OutputCount); |
| } |
| |
| static inline int smb2_ioctl_resp_len(struct smb2_ioctl_req *h) |
| { |
| return le32_to_cpu(h->MaxInputResponse) + |
| le32_to_cpu(h->MaxOutputResponse); |
| } |
| |
| static int smb2_validate_credit_charge(struct ksmbd_conn *conn, |
| struct smb2_hdr *hdr) |
| { |
| unsigned int req_len = 0, expect_resp_len = 0, calc_credit_num, max_len; |
| unsigned short credit_charge = le16_to_cpu(hdr->CreditCharge); |
| void *__hdr = hdr; |
| int ret = 0; |
| |
| switch (hdr->Command) { |
| case SMB2_QUERY_INFO: |
| req_len = smb2_query_info_req_len(__hdr); |
| break; |
| case SMB2_SET_INFO: |
| req_len = smb2_set_info_req_len(__hdr); |
| break; |
| case SMB2_READ: |
| req_len = smb2_read_req_len(__hdr); |
| break; |
| case SMB2_WRITE: |
| req_len = smb2_write_req_len(__hdr); |
| break; |
| case SMB2_QUERY_DIRECTORY: |
| req_len = smb2_query_dir_req_len(__hdr); |
| break; |
| case SMB2_IOCTL: |
| req_len = smb2_ioctl_req_len(__hdr); |
| expect_resp_len = smb2_ioctl_resp_len(__hdr); |
| break; |
| case SMB2_CANCEL: |
| return 0; |
| default: |
| req_len = 1; |
| break; |
| } |
| |
| credit_charge = max_t(unsigned short, credit_charge, 1); |
| max_len = max_t(unsigned int, req_len, expect_resp_len); |
| calc_credit_num = DIV_ROUND_UP(max_len, SMB2_MAX_BUFFER_SIZE); |
| |
| if (credit_charge < calc_credit_num) { |
| ksmbd_debug(SMB, "Insufficient credit charge, given: %d, needed: %d\n", |
| credit_charge, calc_credit_num); |
| return 1; |
| } else if (credit_charge > conn->vals->max_credits) { |
| ksmbd_debug(SMB, "Too large credit charge: %d\n", credit_charge); |
| return 1; |
| } |
| |
| spin_lock(&conn->credits_lock); |
| if (credit_charge > conn->total_credits) { |
| ksmbd_debug(SMB, "Insufficient credits granted, given: %u, granted: %u\n", |
| credit_charge, conn->total_credits); |
| ret = 1; |
| } |
| |
| if ((u64)conn->outstanding_credits + credit_charge > conn->total_credits) { |
| ksmbd_debug(SMB, "Limits exceeding the maximum allowable outstanding requests, given : %u, pending : %u\n", |
| credit_charge, conn->outstanding_credits); |
| ret = 1; |
| } else |
| conn->outstanding_credits += credit_charge; |
| |
| spin_unlock(&conn->credits_lock); |
| |
| return ret; |
| } |
| |
| int ksmbd_smb2_check_message(struct ksmbd_work *work) |
| { |
| struct smb2_pdu *pdu = ksmbd_req_buf_next(work); |
| struct smb2_hdr *hdr = &pdu->hdr; |
| int command; |
| __u32 clc_len; /* calculated length */ |
| __u32 len = get_rfc1002_len(work->request_buf); |
| __u32 req_struct_size, next_cmd = le32_to_cpu(hdr->NextCommand); |
| |
| if ((u64)work->next_smb2_rcv_hdr_off + next_cmd > len) { |
| pr_err("next command(%u) offset exceeds smb msg size\n", |
| next_cmd); |
| return 1; |
| } |
| |
| if (next_cmd > 0) |
| len = next_cmd; |
| else if (work->next_smb2_rcv_hdr_off) |
| len -= work->next_smb2_rcv_hdr_off; |
| |
| if (check_smb2_hdr(hdr)) |
| return 1; |
| |
| if (hdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) { |
| ksmbd_debug(SMB, "Illegal structure size %u\n", |
| le16_to_cpu(hdr->StructureSize)); |
| return 1; |
| } |
| |
| command = le16_to_cpu(hdr->Command); |
| if (command >= NUMBER_OF_SMB2_COMMANDS) { |
| ksmbd_debug(SMB, "Illegal SMB2 command %d\n", command); |
| return 1; |
| } |
| |
| if (smb2_req_struct_sizes[command] != pdu->StructureSize2) { |
| if (!(command == SMB2_OPLOCK_BREAK_HE && |
| (le16_to_cpu(pdu->StructureSize2) == OP_BREAK_STRUCT_SIZE_20 || |
| le16_to_cpu(pdu->StructureSize2) == OP_BREAK_STRUCT_SIZE_21))) { |
| /* special case for SMB2.1 lease break message */ |
| ksmbd_debug(SMB, |
| "Illegal request size %u for command %d\n", |
| le16_to_cpu(pdu->StructureSize2), command); |
| return 1; |
| } |
| } |
| |
| req_struct_size = le16_to_cpu(pdu->StructureSize2) + |
| __SMB2_HEADER_STRUCTURE_SIZE; |
| if (command == SMB2_LOCK_HE) |
| req_struct_size -= sizeof(struct smb2_lock_element); |
| |
| if (req_struct_size > len + 1) |
| return 1; |
| |
| if (smb2_calc_size(hdr, &clc_len)) |
| return 1; |
| |
| if (len != clc_len) { |
| /* client can return one byte more due to implied bcc[0] */ |
| if (clc_len == len + 1) |
| goto validate_credit; |
| |
| /* |
| * Some windows servers (win2016) will pad also the final |
| * PDU in a compound to 8 bytes. |
| */ |
| if (ALIGN(clc_len, 8) == len) |
| goto validate_credit; |
| |
| /* |
| * SMB2 NEGOTIATE request will be validated when message |
| * handling proceeds. |
| */ |
| if (command == SMB2_NEGOTIATE_HE) |
| goto validate_credit; |
| |
| /* |
| * Allow a message that padded to 8byte boundary. |
| * Linux 4.19.217 with smb 3.0.2 are sometimes |
| * sending messages where the cls_len is exactly |
| * 8 bytes less than len. |
| */ |
| if (clc_len < len && (len - clc_len) <= 8) |
| goto validate_credit; |
| |
| pr_err_ratelimited( |
| "cli req too short, len %d not %d. cmd:%d mid:%llu\n", |
| len, clc_len, command, |
| le64_to_cpu(hdr->MessageId)); |
| |
| return 1; |
| } |
| |
| validate_credit: |
| if ((work->conn->vals->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU) && |
| smb2_validate_credit_charge(work->conn, hdr)) |
| return 1; |
| |
| return 0; |
| } |
| |
| int smb2_negotiate_request(struct ksmbd_work *work) |
| { |
| return ksmbd_smb_negotiate_common(work, SMB2_NEGOTIATE_HE); |
| } |