USB: serial: keyspan_pda: fix modem-status error handling

PATCH New Johan Hovold 1 participant 1 message Jul 4, 2018

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Stable branch USB USB serial

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Johan Hovold

author maintainer

2018-07-04 15:02 UTC #0 lore raw

PATCH 1/4 USB: serial: keyspan_pda: fix modem-status error handling

Fix broken modem-status error handling which could lead to bits of slab data leaking to user space.

Fixes 3b36a8fd6777 ("usb: fix uninitialized variable warning in keyspan_pda")

Cc stable <[email protected]> # 2.6.27

Cc Benny Halevy <[email protected]>

Signed-off-by Johan Hovold <[email protected]>

---
 drivers/usb/serial/keyspan_pda.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

drivers/usb/serial/keyspan_pda.c +3 -1

index 5169624d8b11..38d43c4b7ce5 100644
@@ -369,8 +369,10 @@ static int keyspan_pda_get_modem_info(struct usb_serial *serial,
 			     3, /* get pins */
 			     USB_TYPE_VENDOR|USB_RECIP_INTERFACE|USB_DIR_IN,
 			     0, 0, data, 1, 2000);
-	if (rc >= 0)
+	if (rc == 1)
 		*value = *data;
+	else if (rc >= 0)
+		rc = -EIO;
 
 	kfree(data);
 	return rc;