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 08:15:39 +0100 |
| commit | dcbf6a13146c7f1b58feb07f23c6edf80f655e2f (patch) | |
| tree | e03b4f7522a0dc4603a95fe1bc162818db33a32f /drivers | |
| parent | 65295fb9335266472e76cd8155eebaf1f1967489 (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')
| -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 23c6fd238422..21ffcce16927 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2189,7 +2189,8 @@ 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; } |