| From | Greg Kroah-Hartman <> | Subject | [ 016/150] tty: set_termios/set_termiox should not return -EINTR | Date | Tue, 26 Feb 2013 15:54:33 -0800 |
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3.8-stable review patch. If anyone has any objections, please let me know.
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From: Oleg Nesterov <oleg@redhat.com>
commit 183d95cdd834381c594d3aa801c1f9f9c0c54fa9 upstream.
See https://bugzilla.redhat.com/show_bug.cgi?id=904907 read command causes bash to abort with double free or corruption (out).
A simple test-case from Roman:
// Compile the reproducer and send sigchld ti that process. // EINTR occurs even if SA_RESTART flag is set.
void handler(int sig) { }
main() { struct sigaction act; act.sa_handler = handler; act.sa_flags = SA_RESTART; sigaction (SIGCHLD, &act, 0); struct termio ttp; ioctl(0, TCGETA, &ttp); while(1) { if (ioctl(0, TCSETAW, ttp) < 0) { if (errno == EINTR) { fprintf(stderr, "BUG!"); return(1); } } } }
Change set_termios/set_termiox to return -ERESTARTSYS to fix this particular problem.
I didn't dare to change other EINTR's in drivers/tty/, but they look equally wrong.
Reported-by: Roman Rakus <rrakus@redhat.com> Reported-by: Lingzhu Xiang <lxiang@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/tty/tty_ioctl.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/tty/tty_ioctl.c +++ b/drivers/tty/tty_ioctl.c @@ -617,7 +617,7 @@ static int set_termios(struct tty_struct if (opt & TERMIOS_WAIT) { tty_wait_until_sent(tty, 0); if (signal_pending(current)) - return -EINTR; + return -ERESTARTSYS; } tty_set_termios(tty, &tmp_termios); @@ -684,7 +684,7 @@ static int set_termiox(struct tty_struct if (opt & TERMIOS_WAIT) { tty_wait_until_sent(tty, 0); if (signal_pending(current)) - return -EINTR; + return -ERESTARTSYS; } mutex_lock(&tty->termios_mutex);
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