ksmbd: fix potencial out-of-bounds when buffer offset is invalid

I found potencial out-of-bounds when buffer offset fields of a few requests
is invalid. This patch set the minimum value of buffer offset field to
->Buffer offset to validate buffer length.

Cc: stable@vger.kernel.org
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/smb/server/smb2misc.c b/fs/smb/server/smb2misc.c
index 7c872ffb4b0a9821bc6ed4c5d5fe394a74d15a31..727cb49926ee52b7c12e9b784fe4a53432ab51a2 100644 (file)
--- a/fs/smb/server/smb2misc.c
+++ b/fs/smb/server/smb2misc.c
@@ -101,7 +101,9 @@ static int smb2_get_data_area_len(unsigned int *off, unsigned int *len,
                *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);
+               *off = max_t(unsigned short int,
+                            le16_to_cpu(((struct smb2_tree_connect_req *)hdr)->PathOffset),
+                            offsetof(struct smb2_tree_connect_req, Buffer));
                *len = le16_to_cpu(((struct smb2_tree_connect_req *)hdr)->PathLength);
                break;
        case SMB2_CREATE:
@@ -110,7 +112,6 @@ static int smb2_get_data_area_len(unsigned int *off, unsigned int *len,
                        max_t(unsigned short int,
                              le16_to_cpu(((struct smb2_create_req *)hdr)->NameOffset),
                              offsetof(struct smb2_create_req, Buffer));
-
                unsigned short int name_len =
                        le16_to_cpu(((struct smb2_create_req *)hdr)->NameLength);
 
@@ -131,11 +132,15 @@ static int smb2_get_data_area_len(unsigned int *off, unsigned int *len,
                break;
        }
        case SMB2_QUERY_INFO:
-               *off = le16_to_cpu(((struct smb2_query_info_req *)hdr)->InputBufferOffset);
+               *off = max_t(unsigned int,
+                            le16_to_cpu(((struct smb2_query_info_req *)hdr)->InputBufferOffset),
+                            offsetof(struct smb2_query_info_req, Buffer));
                *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);
+               *off = max_t(unsigned int,
+                            le16_to_cpu(((struct smb2_set_info_req *)hdr)->BufferOffset),
+                            offsetof(struct smb2_set_info_req, Buffer));
                *len = le32_to_cpu(((struct smb2_set_info_req *)hdr)->BufferLength);
                break;
        case SMB2_READ:
@@ -145,7 +150,7 @@ static int smb2_get_data_area_len(unsigned int *off, unsigned int *len,
        case SMB2_WRITE:
                if (((struct smb2_write_req *)hdr)->DataOffset ||
                    ((struct smb2_write_req *)hdr)->Length) {
-                       *off = max_t(unsigned int,
+                       *off = max_t(unsigned short 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);
@@ -156,7 +161,9 @@ static int smb2_get_data_area_len(unsigned int *off, unsigned int *len,
                *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);
+               *off = max_t(unsigned short int,
+                            le16_to_cpu(((struct smb2_query_directory_req *)hdr)->FileNameOffset),
+                            offsetof(struct smb2_query_directory_req, Buffer));
                *len = le16_to_cpu(((struct smb2_query_directory_req *)hdr)->FileNameLength);
                break;
        case SMB2_LOCK:
@@ -171,7 +178,9 @@ static int smb2_get_data_area_len(unsigned int *off, unsigned int *len,
                break;
        }
        case SMB2_IOCTL:
-               *off = le32_to_cpu(((struct smb2_ioctl_req *)hdr)->InputOffset);
+               *off = max_t(unsigned int,
+                            le32_to_cpu(((struct smb2_ioctl_req *)hdr)->InputOffset),
+                            offsetof(struct smb2_ioctl_req, Buffer));
                *len = le32_to_cpu(((struct smb2_ioctl_req *)hdr)->InputCount);
                break;
        default:

diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c
index 1ef3859fed1b30c96691ff393fabb52a979913af..3f3408f086699fe9f150af0993e7069d0a743f3d 100644 (file)
--- a/fs/smb/server/smb2pdu.c
+++ b/fs/smb/server/smb2pdu.c
@@ -1927,7 +1927,7 @@ int smb2_tree_connect(struct ksmbd_work *work)
 
        WORK_BUFFERS(work, req, rsp);
 
-       treename = smb_strndup_from_utf16(req->Buffer,
+       treename = smb_strndup_from_utf16((char *)req + le16_to_cpu(req->PathOffset),
                                          le16_to_cpu(req->PathLength), true,
                                          conn->local_nls);
        if (IS_ERR(treename)) {
@@ -2840,7 +2840,7 @@ int smb2_open(struct ksmbd_work *work)
                        goto err_out2;
                }
 
-               name = smb2_get_name(req->Buffer,
+               name = smb2_get_name((char *)req + le16_to_cpu(req->NameOffset),
                                     le16_to_cpu(req->NameLength),
                                     work->conn->local_nls);
                if (IS_ERR(name)) {
@@ -4305,7 +4305,7 @@ int smb2_query_dir(struct ksmbd_work *work)
        }
 
        srch_flag = req->Flags;
-       srch_ptr = smb_strndup_from_utf16(req->Buffer,
+       srch_ptr = smb_strndup_from_utf16((char *)req + le16_to_cpu(req->FileNameOffset),
                                          le16_to_cpu(req->FileNameLength), 1,
                                          conn->local_nls);
        if (IS_ERR(srch_ptr)) {
@@ -4565,7 +4565,8 @@ static int smb2_get_ea(struct ksmbd_work *work, struct ksmbd_file *fp,
                    sizeof(struct smb2_ea_info_req))
                        return -EINVAL;
 
-               ea_req = (struct smb2_ea_info_req *)req->Buffer;
+               ea_req = (struct smb2_ea_info_req *)((char *)req +
+                                                    le16_to_cpu(req->InputBufferOffset));
        } else {
                /* need to send all EAs, if no specific EA is requested*/
                if (le32_to_cpu(req->Flags) & SL_RETURN_SINGLE_ENTRY)
@@ -6211,6 +6212,7 @@ static int smb2_set_info_file(struct ksmbd_work *work, struct ksmbd_file *fp,
                              struct ksmbd_share_config *share)
 {
        unsigned int buf_len = le32_to_cpu(req->BufferLength);
+       char *buffer = (char *)req + le16_to_cpu(req->BufferOffset);
 
        switch (req->FileInfoClass) {
        case FILE_BASIC_INFORMATION:
@@ -6218,7 +6220,7 @@ static int smb2_set_info_file(struct ksmbd_work *work, struct ksmbd_file *fp,
                if (buf_len < sizeof(struct smb2_file_basic_info))
                        return -EINVAL;
 
-               return set_file_basic_info(fp, (struct smb2_file_basic_info *)req->Buffer, share);
+               return set_file_basic_info(fp, (struct smb2_file_basic_info *)buffer, share);
        }
        case FILE_ALLOCATION_INFORMATION:
        {
@@ -6226,7 +6228,7 @@ static int smb2_set_info_file(struct ksmbd_work *work, struct ksmbd_file *fp,
                        return -EINVAL;
 
                return set_file_allocation_info(work, fp,
-                                               (struct smb2_file_alloc_info *)req->Buffer);
+                                               (struct smb2_file_alloc_info *)buffer);
        }
        case FILE_END_OF_FILE_INFORMATION:
        {
@@ -6234,7 +6236,7 @@ static int smb2_set_info_file(struct ksmbd_work *work, struct ksmbd_file *fp,
                        return -EINVAL;
 
                return set_end_of_file_info(work, fp,
-                                           (struct smb2_file_eof_info *)req->Buffer);
+                                           (struct smb2_file_eof_info *)buffer);
        }
        case FILE_RENAME_INFORMATION:
        {
@@ -6242,7 +6244,7 @@ static int smb2_set_info_file(struct ksmbd_work *work, struct ksmbd_file *fp,
                        return -EINVAL;
 
                return set_rename_info(work, fp,
-                                      (struct smb2_file_rename_info *)req->Buffer,
+                                      (struct smb2_file_rename_info *)buffer,
                                       buf_len);
        }
        case FILE_LINK_INFORMATION:
@@ -6251,7 +6253,7 @@ static int smb2_set_info_file(struct ksmbd_work *work, struct ksmbd_file *fp,
                        return -EINVAL;
 
                return smb2_create_link(work, work->tcon->share_conf,
-                                       (struct smb2_file_link_info *)req->Buffer,
+                                       (struct smb2_file_link_info *)buffer,
                                        buf_len, fp->filp,
                                        work->conn->local_nls);
        }
@@ -6261,7 +6263,7 @@ static int smb2_set_info_file(struct ksmbd_work *work, struct ksmbd_file *fp,
                        return -EINVAL;
 
                return set_file_disposition_info(fp,
-                                                (struct smb2_file_disposition_info *)req->Buffer);
+                                                (struct smb2_file_disposition_info *)buffer);
        }
        case FILE_FULL_EA_INFORMATION:
        {
@@ -6274,7 +6276,7 @@ static int smb2_set_info_file(struct ksmbd_work *work, struct ksmbd_file *fp,
                if (buf_len < sizeof(struct smb2_ea_info))
                        return -EINVAL;
 
-               return smb2_set_ea((struct smb2_ea_info *)req->Buffer,
+               return smb2_set_ea((struct smb2_ea_info *)buffer,
                                   buf_len, &fp->filp->f_path, true);
        }
        case FILE_POSITION_INFORMATION:
@@ -6282,14 +6284,14 @@ static int smb2_set_info_file(struct ksmbd_work *work, struct ksmbd_file *fp,
                if (buf_len < sizeof(struct smb2_file_pos_info))
                        return -EINVAL;
 
-               return set_file_position_info(fp, (struct smb2_file_pos_info *)req->Buffer);
+               return set_file_position_info(fp, (struct smb2_file_pos_info *)buffer);
        }
        case FILE_MODE_INFORMATION:
        {
                if (buf_len < sizeof(struct smb2_file_mode_info))
                        return -EINVAL;
 
-               return set_file_mode_info(fp, (struct smb2_file_mode_info *)req->Buffer);
+               return set_file_mode_info(fp, (struct smb2_file_mode_info *)buffer);
        }
        }
 
@@ -6370,7 +6372,7 @@ int smb2_set_info(struct ksmbd_work *work)
                }
                rc = smb2_set_info_sec(fp,
                                       le32_to_cpu(req->AdditionalInformation),
-                                      req->Buffer,
+                                      (char *)req + le16_to_cpu(req->BufferOffset),
                                       le32_to_cpu(req->BufferLength));
                ksmbd_revert_fsids(work);
                break;
@@ -7816,7 +7818,7 @@ static int fsctl_pipe_transceive(struct ksmbd_work *work, u64 id,
                                 struct smb2_ioctl_rsp *rsp)
 {
        struct ksmbd_rpc_command *rpc_resp;
-       char *data_buf = (char *)&req->Buffer[0];
+       char *data_buf = (char *)req + le32_to_cpu(req->InputOffset);
        int nbytes = 0;
 
        rpc_resp = ksmbd_rpc_ioctl(work->sess, id, data_buf,
@@ -7929,6 +7931,7 @@ int smb2_ioctl(struct ksmbd_work *work)
        u64 id = KSMBD_NO_FID;
        struct ksmbd_conn *conn = work->conn;
        int ret = 0;
+       char *buffer;
 
        if (work->next_smb2_rcv_hdr_off) {
                req = ksmbd_req_buf_next(work);
@@ -7951,6 +7954,8 @@ int smb2_ioctl(struct ksmbd_work *work)
                goto out;
        }
 
+       buffer = (char *)req + le32_to_cpu(req->InputOffset);
+
        cnt_code = le32_to_cpu(req->CtlCode);
        ret = smb2_calc_max_out_buf_len(work, 48,
                                        le32_to_cpu(req->MaxOutputResponse));
@@ -8008,7 +8013,7 @@ int smb2_ioctl(struct ksmbd_work *work)
                }
 
                ret = fsctl_validate_negotiate_info(conn,
-                       (struct validate_negotiate_info_req *)&req->Buffer[0],
+                       (struct validate_negotiate_info_req *)buffer,
                        (struct validate_negotiate_info_rsp *)&rsp->Buffer[0],
                        in_buf_len);
                if (ret < 0)
@@ -8061,7 +8066,7 @@ int smb2_ioctl(struct ksmbd_work *work)
                rsp->VolatileFileId = req->VolatileFileId;
                rsp->PersistentFileId = req->PersistentFileId;
                fsctl_copychunk(work,
-                               (struct copychunk_ioctl_req *)&req->Buffer[0],
+                               (struct copychunk_ioctl_req *)buffer,
                                le32_to_cpu(req->CtlCode),
                                le32_to_cpu(req->InputCount),
                                req->VolatileFileId,
@@ -8074,8 +8079,7 @@ int smb2_ioctl(struct ksmbd_work *work)
                        goto out;
                }
 
-               ret = fsctl_set_sparse(work, id,
-                                      (struct file_sparse *)&req->Buffer[0]);
+               ret = fsctl_set_sparse(work, id, (struct file_sparse *)buffer);
                if (ret < 0)
                        goto out;
                break;
@@ -8098,7 +8102,7 @@ int smb2_ioctl(struct ksmbd_work *work)
                }
 
                zero_data =
-                       (struct file_zero_data_information *)&req->Buffer[0];
+                       (struct file_zero_data_information *)buffer;
 
                off = le64_to_cpu(zero_data->FileOffset);
                bfz = le64_to_cpu(zero_data->BeyondFinalZero);
@@ -8129,7 +8133,7 @@ int smb2_ioctl(struct ksmbd_work *work)
                }
 
                ret = fsctl_query_allocated_ranges(work, id,
-                       (struct file_allocated_range_buffer *)&req->Buffer[0],
+                       (struct file_allocated_range_buffer *)buffer,
                        (struct file_allocated_range_buffer *)&rsp->Buffer[0],
                        out_buf_len /
                        sizeof(struct file_allocated_range_buffer), &nbytes);
@@ -8173,7 +8177,7 @@ int smb2_ioctl(struct ksmbd_work *work)
                        goto out;
                }
 
-               dup_ext = (struct duplicate_extents_to_file *)&req->Buffer[0];
+               dup_ext = (struct duplicate_extents_to_file *)buffer;
 
                fp_in = ksmbd_lookup_fd_slow(work, dup_ext->VolatileFileHandle,
                                             dup_ext->PersistentFileHandle);