@@ -29,16 +29,31 @@ void restore_term(void)
return;
tcsetattr(term_fd, TCSAFLUSH, &old_term);
+
close(term_fd);
term_fd = -1;
}
+static int is_controlling_terminal(int fd)
+{
+ return (getpgid(0) == tcgetpgrp(fd));
+}
+
int save_term(int full_duplex)
{
if (term_fd < 0)
term_fd = open("/dev/tty", O_RDWR);
- return (term_fd < 0) ? -1 : tcgetattr(term_fd, &old_term);
+ if (term_fd < 0)
+ return -1;
+
+ if (full_duplex && !is_controlling_terminal(term_fd)) {
+ close(term_fd);
+ term_fd = -1;
+ return -1;
+ }
+
+ return tcgetattr(term_fd, &old_term);
}
static int disable_bits(tcflag_t bits)
e22b245ea5 (terminal: teach git how to save/restore its terminal settings, 2021-10-05) allows external calls to the termios code, but kept the assumption that all operations were done with foreground processes, which was proven incorrect. Add a check to validate that the current process is indeed in the foreground and in control of the terminal and fail early if not the case. To avoid changing behaviour from the other users of save_term() the full_duplex parameter has been overloaded to restrict the new check to only future callers, as it is set to 0 for all current users. The detection is done in a helper function so it can be reused by all other functions that might benefit from it later, and once that is done that overloading might be unnecessary and cleaned up, but doing so has been punted from this series as it is not needed and might require backward incompatible changes. Helped-by: Phillip Wood <phillip.wood123@gmail.com> Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com> --- compat/terminal.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-)