ksmbd: validate OutputBufferLength of QUERY_DIR, QUERY_INFO, IOCTL requests

Validate OutputBufferLength of QUERY_DIR, QUERY_INFO, IOCTL requests and
check the free size of response buffer for these requests.

Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index 7999d8b..e0f3a44 100644 (file)
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -3762,6 +3762,24 @@ static int verify_info_level(int info_level)
        return 0;
 }
 
+static int smb2_calc_max_out_buf_len(struct ksmbd_work *work,
+                                    unsigned short hdr2_len,
+                                    unsigned int out_buf_len)
+{
+       int free_len;
+
+       if (out_buf_len > work->conn->vals->max_trans_size)
+               return -EINVAL;
+
+       free_len = (int)(work->response_sz -
+                        (get_rfc1002_len(work->response_buf) + 4)) -
+               hdr2_len;
+       if (free_len < 0)
+               return -EINVAL;
+
+       return min_t(int, out_buf_len, free_len);
+}
+
 int smb2_query_dir(struct ksmbd_work *work)
 {
        struct ksmbd_conn *conn = work->conn;
@@ -3838,9 +3856,13 @@ int smb2_query_dir(struct ksmbd_work *work)
        memset(&d_info, 0, sizeof(struct ksmbd_dir_info));
        d_info.wptr = (char *)rsp->Buffer;
        d_info.rptr = (char *)rsp->Buffer;
-       d_info.out_buf_len = (work->response_sz - (get_rfc1002_len(rsp_org) + 4));
-       d_info.out_buf_len = min_t(int, d_info.out_buf_len, le32_to_cpu(req->OutputBufferLength)) -
-               sizeof(struct smb2_query_directory_rsp);
+       d_info.out_buf_len =
+               smb2_calc_max_out_buf_len(work, 8,
+                                         le32_to_cpu(req->OutputBufferLength));
+       if (d_info.out_buf_len < 0) {
+               rc = -EINVAL;
+               goto err_out;
+       }
        d_info.flags = srch_flag;
 
        /*
@@ -4074,12 +4096,11 @@ static int smb2_get_ea(struct ksmbd_work *work, struct ksmbd_file *fp,
                                    le32_to_cpu(req->Flags));
        }
 
-       buf_free_len = work->response_sz -
-                       (get_rfc1002_len(rsp_org) + 4) -
-                       sizeof(struct smb2_query_info_rsp);
-
-       if (le32_to_cpu(req->OutputBufferLength) < buf_free_len)
-               buf_free_len = le32_to_cpu(req->OutputBufferLength);
+       buf_free_len =
+               smb2_calc_max_out_buf_len(work, 8,
+                                         le32_to_cpu(req->OutputBufferLength));
+       if (buf_free_len < 0)
+               return -EINVAL;
 
        rc = ksmbd_vfs_listxattr(path->dentry, &xattr_list);
        if (rc < 0) {
@@ -4390,6 +4411,8 @@ static void get_file_stream_info(struct ksmbd_work *work,
        struct path *path = &fp->filp->f_path;
        ssize_t xattr_list_len;
        int nbytes = 0, streamlen, stream_name_len, next, idx = 0;
+       int buf_free_len;
+       struct smb2_query_info_req *req = ksmbd_req_buf_next(work);
 
        generic_fillattr(file_mnt_user_ns(fp->filp), file_inode(fp->filp),
                         &stat);
@@ -4403,6 +4426,12 @@ static void get_file_stream_info(struct ksmbd_work *work,
                goto out;
        }
 
+       buf_free_len =
+               smb2_calc_max_out_buf_len(work, 8,
+                                         le32_to_cpu(req->OutputBufferLength));
+       if (buf_free_len < 0)
+               goto out;
+
        while (idx < xattr_list_len) {
                stream_name = xattr_list + idx;
                streamlen = strlen(stream_name);
@@ -4427,6 +4456,10 @@ static void get_file_stream_info(struct ksmbd_work *work,
                streamlen = snprintf(stream_buf, streamlen + 1,
                                     ":%s", &stream_name[XATTR_NAME_STREAM_LEN]);
 
+               next = sizeof(struct smb2_file_stream_info) + streamlen * 2;
+               if (next > buf_free_len)
+                       break;
+
                file_info = (struct smb2_file_stream_info *)&rsp->Buffer[nbytes];
                streamlen  = smbConvertToUTF16((__le16 *)file_info->StreamName,
                                               stream_buf, streamlen,
@@ -4437,12 +4470,13 @@ static void get_file_stream_info(struct ksmbd_work *work,
                file_info->StreamSize = cpu_to_le64(stream_name_len);
                file_info->StreamAllocationSize = cpu_to_le64(stream_name_len);
 
-               next = sizeof(struct smb2_file_stream_info) + streamlen;
                nbytes += next;
+               buf_free_len -= next;
                file_info->NextEntryOffset = cpu_to_le32(next);
        }
 
-       if (!S_ISDIR(stat.mode)) {
+       if (!S_ISDIR(stat.mode) &&
+           buf_free_len >= sizeof(struct smb2_file_stream_info) + 7 * 2) {
                file_info = (struct smb2_file_stream_info *)
                        &rsp->Buffer[nbytes];
                streamlen = smbConvertToUTF16((__le16 *)file_info->StreamName,
@@ -7453,11 +7487,13 @@ int smb2_ioctl(struct ksmbd_work *work)
        }
 
        cnt_code = le32_to_cpu(req->CntCode);
-       out_buf_len = le32_to_cpu(req->MaxOutputResponse);
-       out_buf_len =
-               min_t(u32, work->response_sz - work->next_smb2_rsp_hdr_off -
-                               (offsetof(struct smb2_ioctl_rsp, Buffer) - 4),
-                     out_buf_len);
+       ret = smb2_calc_max_out_buf_len(work, 48,
+                                       le32_to_cpu(req->MaxOutputResponse));
+       if (ret < 0) {
+               rsp->hdr.Status = STATUS_INVALID_PARAMETER;
+               goto out;
+       }
+       out_buf_len = (unsigned int)ret;
        in_buf_len = le32_to_cpu(req->InputCount);
 
        switch (cnt_code) {