From 370e8e2937e0b0ba283e498f6c13b1fe431a8752 Mon Sep 17 00:00:00 2001 From: Takashi Yano Date: Sat, 3 Feb 2024 00:54:23 +0900 Subject: [PATCH] Cygwin: console: Avoid slipping past disable_master_thread check. If disable_master_thread flag is set between the code checking that flag not be set and the code acquiring input_mutex, input record is processed once after setting disable_master_thread flag. This patch prevents that. Fixes: d4aacd50e6cf ("Cygwin: console: Add missing input_mutex guard.") Signed-off-by: Takashi Yano --- winsup/cygwin/fhandler/console.cc | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/winsup/cygwin/fhandler/console.cc b/winsup/cygwin/fhandler/console.cc index 6a42b49491..1c8d383cdd 100644 --- a/winsup/cygwin/fhandler/console.cc +++ b/winsup/cygwin/fhandler/console.cc @@ -420,6 +420,12 @@ fhandler_console::cons_master_thread (handle_set_t *p, tty *ttyp) } WaitForSingleObject (p->input_mutex, mutex_timeout); + /* Ensure accessing input recored is not disabled. */ + if (con.disable_master_thread) + { + ReleaseMutex (p->input_mutex); + continue; + } total_read = 0; switch (cygwait (p->input_handle, (DWORD) 0)) { @@ -4545,8 +4551,6 @@ fhandler_console::set_disable_master_thread (bool x, fhandler_console *cons) return; } const _minor_t unit = cons->get_minor (); - if (con.disable_master_thread == x) - return; cons->acquire_input_mutex (mutex_timeout); con.disable_master_thread = x; cons->release_input_mutex ();