From: Daniel Starke <daniel.starke@xxxxxxxxxxx> gsmld_poll() currently fails to handle the following corner cases correctly: - remote party closed the associated tty Add the missing checks and map those to EPOLLHUP. Reorder the checks to group them by their reaction. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Signed-off-by: Daniel Starke <daniel.starke@xxxxxxxxxxx> --- drivers/tty/n_gsm.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) Check for valid pointer in tty->disc_data has been removed compared to v1. Link: https://lore.kernel.org/all/17759c4b-5858-12bb-4beb-c4a1d58c89ae@xxxxxxxxxx/ diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 51447ccccbab..caa5c14ed57f 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -3053,12 +3053,15 @@ static __poll_t gsmld_poll(struct tty_struct *tty, struct file *file, poll_wait(file, &tty->read_wait, wait); poll_wait(file, &tty->write_wait, wait); + + if (gsm->dead) + mask |= EPOLLHUP; if (tty_hung_up_p(file)) mask |= EPOLLHUP; + if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) + mask |= EPOLLHUP; if (!tty_is_writelocked(tty) && tty_write_room(tty) > 0) mask |= EPOLLOUT | EPOLLWRNORM; - if (gsm->dead) - mask |= EPOLLHUP; return mask; } -- 2.34.1