In the condition that console setup for CTTY and close run at the sametime, accessing shared console memory which is already unmapped may occur. With this patch, to avoid this race issue, shared console memory which belongs to contorolling terminal (CTTY) is kept mapped as before. Addresses: https://cygwin.com/pipermail/cygwin/2024-February/255561.html
Fixes: 3721a756b0d8 ("Cygwin: console: Make the console accessible from other terminals.") Reported-by: Kate Deplaix <kit-ty-k...@outlook.com> Signed-off-by: Takashi Yano <takashi.y...@nifty.ne.jp> --- winsup/cygwin/fhandler/console.cc | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/winsup/cygwin/fhandler/console.cc b/winsup/cygwin/fhandler/console.cc index c16ca3962..67ea95466 100644 --- a/winsup/cygwin/fhandler/console.cc +++ b/winsup/cygwin/fhandler/console.cc @@ -1926,9 +1926,11 @@ fhandler_console::close () || get_device () == (dev_t) myself->ctty)) free_console (); - if (shared_console_info[unit]) - UnmapViewOfFile ((void *) shared_console_info[unit]); - shared_console_info[unit] = NULL; + if (shared_console_info[unit] && myself->ctty != tc ()->ntty) + { + UnmapViewOfFile ((void *) shared_console_info[unit]); + shared_console_info[unit] = NULL; + } return 0; } -- 2.43.0