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| author |   Peter Hurley <peter@hurleysoftware.com> | 2016-01-10 22:40:58 -0800 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-01-26 23:17:54 -0800 |
| commit | f4f9edcf9b5289ed96113e79fa65a7bf27ecb096 (patch) | |
| tree | 6cf6e1b2eff3ed51f0320bf9971eb27af8bf6e26 | |
| parent | n_tty: Fix unsafe reference to "other" ldisc (diff) | |
| download | linux-dev-f4f9edcf9b5289ed96113e79fa65a7bf27ecb096.tar.xz linux-dev-f4f9edcf9b5289ed96113e79fa65a7bf27ecb096.zip | |
staging/speakup: Use tty_ldisc_ref() for paste kworker
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@vger.kernel.org>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/staging/speakup/selection.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/staging/speakup/selection.c b/drivers/staging/speakup/selection.c index aa5ab6c80ed4..41ef099b7aa6 100644 --- a/drivers/staging/speakup/selection.c +++ b/drivers/staging/speakup/selection.c @@ -142,7 +142,9 @@ 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); @@ -162,6 +164,7 @@ 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); } |