diff options
| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-20 10:46:58 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-31 08:12:35 +0100 |
| commit | 0609c03246ebb1b83a5b6c6eb3343fe9f08d8c7b (patch) | |
| tree | 5fa8fdf349808dd1e0468dced780eecc632a9e4c /drivers/tty | |
| parent | dff6b7b31d650424de0c9fb9038a20f37350a13f (diff) | |
tty: Handle problem if line discipline does not have receive_buf
commit 27cfb3a53be46a54ec5e0bd04e51995b74c90343 upstream.
Some tty line disciplines do not have a receive buf callback, so
properly check for that before calling it. If they do not have this
callback, just eat the character quietly, as we can't fail this call.
Reported-by: Jann Horn <jannh@google.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/tty_io.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index f61f8650665f..19fe1e8fc124 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2324,7 +2324,8 @@ static int tiocsti(struct tty_struct *tty, char __user *p) ld = tty_ldisc_ref_wait(tty); if (!ld) return -EIO; - ld->ops->receive_buf(tty, &ch, &mbz, 1); + if (ld->ops->receive_buf) + ld->ops->receive_buf(tty, &ch, &mbz, 1); tty_ldisc_deref(ld); return 0; } |