[PATCH] Cygwin: pty: Fix segfault caused when tcflush() is called.

[Corinna Vinschen]

On Feb 21 07:45, Takashi Yano via Cygwin-patches wrote:
> - After commit 253352e796ff9ec9a447e5375f5bc3e2b92b5293, mc (midnight
>   commander) crashes with segfault if the shell is bash. This is due
>   to NULL pointer access in read(). This patch fixes the issue.
>   Addresses::
>     https://cygwin.com/pipermail/cygwin/2021-February/247870.html
> ---
>  winsup/cygwin/fhandler_tty.cc | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/winsup/cygwin/fhandler_tty.cc b/winsup/cygwin/fhandler_tty.cc
> index d30041af1..3fcaa8277 100644
> --- a/winsup/cygwin/fhandler_tty.cc
> +++ b/winsup/cygwin/fhandler_tty.cc
> @@ -1474,8 +1474,11 @@ wait_retry:
>  out:
>    termios_printf ("%d = read(%p, %lu)", totalread, ptr, len);
>    len = (size_t) totalread;
> -  bool saw_eol = totalread > 0 && strchr ("\r\n", ptr0[totalread -1]);
> -  mask_switch_to_pcon_in (false, saw_eol);
> +  if (ptr0)
> +    { /* Not tcflush() */
> +      bool saw_eol = totalread > 0 && strchr ("\r\n", ptr0[totalread -1]);
> +      mask_switch_to_pcon_in (false, saw_eol);
> +    }
>  }
>  
>  int
> -- 
> 2.30.0

Pushed.

So, what do you think is the state of the console code, Takashi?
Shall we start a release cycle next week?


Thanks,
Corinna