From: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>
This patch has been added to the 4.1 stable tree. If you have any
objections, please let us know.
===============
[ Upstream commit f4f9edcf9b5289ed96113e79fa65a7bf27ecb096 ]
As the function documentation for tty_ldisc_ref_wait() notes, it is
only callable from a tty file_operations routine; otherwise there
is no guarantee the ref won't be NULL.
The key difference with the VT's paste_selection() is that is an ioctl,
where __speakup_paste_selection() is completely async kworker, kicked
off from interrupt context.
Fixes: 28a821c30688 ("Staging: speakup: Update __speakup_paste_selection()
tty (ab)usage to match vt")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
---
drivers/staging/speakup/selection.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/staging/speakup/selection.c b/drivers/staging/speakup/selection.c
index a031570..ed68b2c 100644
--- a/drivers/staging/speakup/selection.c
+++ b/drivers/staging/speakup/selection.c
@@ -141,7 +141,9 @@ static void __speakup_paste_selection(struct work_struct *work)
struct tty_ldisc *ld;
DECLARE_WAITQUEUE(wait, current);
- ld = tty_ldisc_ref_wait(tty);
+ ld = tty_ldisc_ref(tty);
+ if (!ld)
+ goto tty_unref;
tty_buffer_lock_exclusive(&vc->port);
add_wait_queue(&vc->paste_wait, &wait);
@@ -161,6 +163,7 @@ static void __speakup_paste_selection(struct work_struct *work)
tty_buffer_unlock_exclusive(&vc->port);
tty_ldisc_deref(ld);
+tty_unref:
tty_kref_put(tty);
}
--
2.5.0
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