From: Johan Hovold <johan@kernel.org>
Date: Wed, 4 Jul 2018 15:02:16 +0000 (+0200)
Subject: USB: serial: keyspan_pda: fix modem-status error handling
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=f24b02c3a0818651f179bdf1026a8de67a97070f;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

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

commit 01b3cdfca263a17554f7b249d20a247b2a751521 upstream.

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 <stable@vger.kernel.org>     # 2.6.27
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c
index 196908dd25a1..f8e8285663a6 100644
--- a/drivers/usb/serial/keyspan_pda.c
+++ b/drivers/usb/serial/keyspan_pda.c
@@ -373,8 +373,10 @@ 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;