This is a note to let you know that I've just added the patch titled
tty: n_gsm: fix missing corner cases in gsmld_poll()
to the 5.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tty-n_gsm-fix-missing-corner-cases-in-gsmld_poll.patch
and it can be found in the queue-5.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0e6b2b1ff652ff583bcd85665aaa1f5fd0c909aa
Author: Daniel Starke <daniel.starke@xxxxxxxxxxx>
Date: Thu Jul 7 13:32:23 2022 +0200
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: e1eaea46bb40 ("tty: n_gsm line discipline")
Signed-off-by: Daniel Starke <daniel.starke@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220707113223.3685-4-daniel.starke@xxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 7749de4f269a..3dd71ede4cd4 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -3057,12 +3057,15 @@ 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;
}
