diff options
| author | Johan Hovold <johan@kernel.org> | 2017-01-31 17:17:29 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2017-06-05 21:13:46 +0100 |
| commit | b9d711c45a310cd150bddced2604a70115059c2b (patch) | |
| tree | c60d5407adaa550213719ecdf8aeeb91ad76def0 | |
| parent | 0ec745967dbf486a05082f67e67910afa3a9d319 (diff) | |
USB: serial: keyspan_pda: fix receive sanity checks
commit c528fcb116e61afc379a2e0a0f70906b937f1e2c upstream.
Make sure to check for short transfers before parsing the receive buffer
to avoid acting on stale data.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
[bwh: Backported to 3.2:
- Adjust context
- Keep the check for !tty in the data case]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | drivers/usb/serial/keyspan_pda.c | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c index 65a090660e73..611904f1650c 100644 --- a/drivers/usb/serial/keyspan_pda.c +++ b/drivers/usb/serial/keyspan_pda.c @@ -212,6 +212,7 @@ static void keyspan_pda_rx_interrupt(struct urb *urb) struct usb_serial_port *port = urb->context; struct tty_struct *tty; unsigned char *data = urb->transfer_buffer; + unsigned int len = urb->actual_length; int retval; int status = urb->status; struct keyspan_pda_private *priv; @@ -234,20 +235,28 @@ static void keyspan_pda_rx_interrupt(struct urb *urb) goto exit; } + if (len < 1) { + dev_warn(&port->dev, "short message received\n"); + goto exit; + } + /* see if the message is data or a status interrupt */ switch (data[0]) { case 0: tty = tty_port_tty_get(&port->port); /* rest of message is rx data */ - if (tty && urb->actual_length) { - tty_insert_flip_string(tty, data + 1, - urb->actual_length - 1); - tty_flip_buffer_push(tty); - } + if (!tty || len < 2) + break; + tty_insert_flip_string(tty, data + 1, len - 1); + tty_flip_buffer_push(tty); tty_kref_put(tty); break; case 1: /* status interrupt */ + if (len < 3) { + dev_warn(&port->dev, "short interrupt message received\n"); + break; + } dbg(" rx int, d1=%d, d2=%d", data[1], data[2]); switch (data[1]) { case 1: /* modemline change */ |