Cygwin: console: Avoid accessing NULL pointer via cygheap->ctty.

- Recent commit "Cygwin: console: Add missing input_mutex guard."
  has a problem that causes NULL pointer access if cygheap->ctty
  is NULL. This patch fixes the issue.
This commit is contained in:
Takashi Yano 2022-07-29 21:40:18 +09:00
parent d4689b99c6
commit 8d564b62b7
2 changed files with 15 additions and 9 deletions

View File

@ -2298,7 +2298,7 @@ private:
static void cleanup_for_non_cygwin_app (handle_set_t *p);
static void set_console_mode_to_native ();
bool need_console_handler ();
static void set_disable_master_thread (bool x);
static void set_disable_master_thread (bool x, fhandler_console *cons = NULL);
friend tty_min * tty_list::get_cttyp ();
};

View File

@ -791,7 +791,7 @@ fhandler_console::setup_for_non_cygwin_app ()
(get_ttyp ()->getpgid ()== myself->pgid) ? tty::native : tty::restore;
set_input_mode (conmode, &tc ()->ti, get_handle_set ());
set_output_mode (conmode, &tc ()->ti, get_handle_set ());
set_disable_master_thread (true);
set_disable_master_thread (true, this);
}
void
@ -986,7 +986,7 @@ fhandler_console::bg_check (int sig, bool dontsignal)
if (sig == SIGTTIN)
{
set_input_mode (tty::cygwin, &tc ()->ti, get_handle_set ());
set_disable_master_thread (false);
set_disable_master_thread (false, this);
}
if (sig == SIGTTOU)
set_output_mode (tty::cygwin, &tc ()->ti, get_handle_set ());
@ -1721,7 +1721,7 @@ fhandler_console::post_open_setup (int fd)
if (fd == 0)
{
set_input_mode (tty::cygwin, &get_ttyp ()->ti, &handle_set);
set_disable_master_thread (false);
set_disable_master_thread (false, this);
}
else if (fd == 1 || fd == 2)
set_output_mode (tty::cygwin, &get_ttyp ()->ti, &handle_set);
@ -1749,7 +1749,7 @@ fhandler_console::close ()
/* Cleaning-up console mode for cygwin apps. */
set_output_mode (tty::restore, &get_ttyp ()->ti, &handle_set);
set_input_mode (tty::restore, &get_ttyp ()->ti, &handle_set);
set_disable_master_thread (true);
set_disable_master_thread (true, this);
}
}
@ -3975,7 +3975,7 @@ fhandler_console::set_console_mode_to_native ()
termios *cons_ti = &cons->tc ()->ti;
set_input_mode (tty::native, cons_ti, cons->get_handle_set ());
set_output_mode (tty::native, cons_ti, cons->get_handle_set ());
set_disable_master_thread (true);
set_disable_master_thread (true, cons);
break;
}
}
@ -4321,11 +4321,17 @@ fhandler_console::need_console_handler ()
}
void
fhandler_console::set_disable_master_thread (bool x)
fhandler_console::set_disable_master_thread (bool x, fhandler_console *cons)
{
if (cygheap->ctty->get_major () != DEV_CONS_MAJOR)
if (con.disable_master_thread == x)
return;
fhandler_console *cons = (fhandler_console *) cygheap->ctty;
if (cons == NULL)
{
if (cygheap->ctty && cygheap->ctty->get_major () == DEV_CONS_MAJOR)
cons = (fhandler_console *) cygheap->ctty;
else
return;
}
cons->acquire_input_mutex (mutex_timeout);
con.disable_master_thread = x;
cons->release_input_mutex ();