diff options
| author | Johan Hovold <johan@kernel.org> | 2017-01-31 17:17:27 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2017-06-05 21:13:46 +0100 |
| commit | 90f4c688d372b04cf401906098fc03db0a567814 (patch) | |
| tree | 41ba40af887db5594c2845278fa125fafc78e3c8 | |
| parent | 6e6fb360d9b9741c1a063e6659760e4dc4c056be (diff) | |
USB: serial: digi_acceleport: fix OOB data sanity check
commit 2d380889215fe20b8523345649dee0579821800c upstream.
Make sure to check for short transfers to avoid underflow in a loop
condition when parsing the receive buffer.
Also fix an off-by-one error in the incomplete sanity check which could
lead to invalid data being parsed.
Fixes: 8c209e6782ca ("USB: make actual_length in struct urb field u32")
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]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | drivers/usb/serial/digi_acceleport.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/drivers/usb/serial/digi_acceleport.c b/drivers/usb/serial/digi_acceleport.c index e59bd95f05c0..24c9fc82bc90 100644 --- a/drivers/usb/serial/digi_acceleport.c +++ b/drivers/usb/serial/digi_acceleport.c @@ -1746,6 +1746,7 @@ static int digi_read_oob_callback(struct urb *urb) struct usb_serial *serial = port->serial; struct tty_struct *tty; struct digi_port *priv = usb_get_serial_port_data(port); + unsigned char *buf = urb->transfer_buffer; int opcode, line, status, val; int i; unsigned int rts; @@ -1753,12 +1754,15 @@ static int digi_read_oob_callback(struct urb *urb) dbg("digi_read_oob_callback: port=%d, len=%d", priv->dp_port_num, urb->actual_length); + if (urb->actual_length < 4) + return -1; + /* handle each oob command */ - for (i = 0; i < urb->actual_length - 3;) { - opcode = ((unsigned char *)urb->transfer_buffer)[i++]; - line = ((unsigned char *)urb->transfer_buffer)[i++]; - status = ((unsigned char *)urb->transfer_buffer)[i++]; - val = ((unsigned char *)urb->transfer_buffer)[i++]; + for (i = 0; i < urb->actual_length - 4; i += 4) { + opcode = buf[i]; + line = buf[i + 1]; + status = buf[i + 2]; + val = buf[i + 3]; dbg("digi_read_oob_callback: opcode=%d, line=%d, status=%d, val=%d", opcode, line, status, val); |