Messages in this thread Patch in this message | | | From | Kamal Mostafa <> | Subject | [PATCH 3.19.y-ckt 31/47] n_tty: Fix unsafe reference to "other" ldisc | Date | Tue, 9 Feb 2016 14:44:45 -0800 |
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3.19.8-ckt15 -stable review patch. If anyone has any objections, please let me know.
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From: Peter Hurley <peter@hurleysoftware.com>
commit 6d27a63caad3f13e96cf065d2d96828c2006be6b upstream.
Although n_tty_check_unthrottle() has a valid ldisc reference (since the tty core gets the ldisc ref in tty_read() before calling the line discipline read() method), it does not have a valid ldisc reference to the "other" pty of a pty pair. Since getting an ldisc reference for tty->link essentially open-codes tty_wakeup(), just replace with the equivalent tty_wakeup().
Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- drivers/tty/n_tty.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index bcbd73d..1f37a75 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -277,16 +277,13 @@ static void n_tty_check_throttle(struct tty_struct *tty) static void n_tty_check_unthrottle(struct tty_struct *tty) { - if (tty->driver->type == TTY_DRIVER_TYPE_PTY && - tty->link->ldisc->ops->write_wakeup == n_tty_write_wakeup) { + if (tty->driver->type == TTY_DRIVER_TYPE_PTY) { if (chars_in_buffer(tty) > TTY_THRESHOLD_UNTHROTTLE) return; if (!tty->count) return; n_tty_set_room(tty); - n_tty_write_wakeup(tty->link); - if (waitqueue_active(&tty->link->write_wait)) - wake_up_interruptible_poll(&tty->link->write_wait, POLLOUT); + tty_wakeup(tty->link); return; } -- 1.9.1
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