Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 44913ccf authored by Daniel Starke's avatar Daniel Starke Committed by Greg Kroah-Hartman
Browse files

tty: n_gsm: fix missing corner cases in gsmld_poll() 



[ Upstream commit 7e5b4322cde067e1d0f1bf8f490e93f664a7c843 ]

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: e1eaea46 ("tty: n_gsm line discipline")
Signed-off-by: default avatarDaniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20220707113223.3685-4-daniel.starke@siemens.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent ae9bfcbf

drivers/tty/n_gsm.c

+5 −2
Original line number Diff line number Diff line
@@ -2693,12 +2693,15 @@ 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;

}