From 794744abfffef8b1f3c0c8a4896177d6d13d653d Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Wed, 4 Jul 2018 17:02:17 +0200
Subject: [PATCH] USB: serial: mos7840: fix status-register error handling
Git-commit: 794744abfffef8b1f3c0c8a4896177d6d13d653d
Patch-mainline: v4.18-rc5
References: bsc#1051510
Add missing transfer-length sanity check to the status-register
completion handler to avoid leaking bits of uninitialised slab data to
user space.
Fixes: 3f5429746d91 ("USB: Moschip 7840 USB-Serial Driver")
Cc: stable <stable@vger.kernel.org> # 2.6.19
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/usb/serial/mos7840.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c
index fdceb46d9fc6..b580b4c7fa48 100644
--- a/drivers/usb/serial/mos7840.c
+++ b/drivers/usb/serial/mos7840.c
@@ -468,6 +468,9 @@ static void mos7840_control_callback(struct urb *urb)
}
dev_dbg(dev, "%s urb buffer size is %d\n", __func__, urb->actual_length);
+ if (urb->actual_length < 1)
+ goto out;
+
dev_dbg(dev, "%s mos7840_port->MsrLsr is %d port %d\n", __func__,
mos7840_port->MsrLsr, mos7840_port->port_num);
data = urb->transfer_buffer;
--
2.18.0