c - Memory leak on returning pointer -

i facing memory leak condition in following functions.

char * readdatafromfile(unsigned pagenumber) {     char *buff = (char*) malloc(sizeof(char) * pagesize);     lseek(fd, pagesize * (pagenumber), seek_set);     read(fd, buff, pagesize);      return buff; } //read file char * readfromfile(char *fname, int pageno) {     char *buff = null;     fd = searchinvector(fname);     if (fd > 0)         buff = readdatafromfile(pageno);     else         printf("\nindex not opened\n");     return buff; } 

i trying call function following way

char* root_buf = readfromfile(fname,pageno); 

can point me memory leak occurs , how overcome it.

edit

i call free(root_buf); later. forgot mention part. believe has fact creating pointer , returning it. maybe reference caught in pointer in caller function.

the memory allocated using malloc never freed again. if call site:

char* root_buf = readfromfile(fname,pageno);  // stuff free(root_buf); 

it should solve leak.