Skip to content
  • Ilya Pominov's avatar
    c_client: Fix crash in xcb_randr_set_monitor · 03863678
    Ilya Pominov authored
    Take into account c_need_sizeof when evaluating
    xcb_protocol_request_t.count
    
    Incorrect xcb_protocol_request_t.count causes a segmentation fault when
    calling functions:
    - xcb_randr_set_monitor{_checked}
    - xcb_input_change_feedback_control{_checked}
    - xcb_input_change_device_control{_unchecked}
    
    Steps to reproduce:
    Call xcb_randr_set_monitor() with valid arguments
    
    OBSERVED RESULT
    Segmentation fault
    ```
    Process terminating with default action of signal 11 (SIGSEGV)
      Access not within mapped region at address 0x780
        at 0x4852925: memmove (in /usr/libexec/valgrind/vgpreload_memcheck-
    amd64-linux.so)
        by 0x486967C: memcpy (string_fortified.h:29)
        by 0x486967C: send_request (xcb_out.c:59)
        by 0x486967C: send_request (xcb_out.c:46)
        by 0x486967C: xcb_send_request_with_fds64 (xcb_out.c:338)
        by 0x48699FC: xcb_send_request (xcb_out.c:359)
        by 0x4891F11: xcb_randr_set_monitor_checked (randr.c:5350)
    ```
    
    EXPECTED RESULT
    Function returns cookie
    
    Amen...
    03863678