From: Alexey Khoroshilov <khoroshilov@ispras.ru>
Date: Thu, 11 Aug 2016 22:05:09 +0000 (+0300)
Subject: USB: serial: mos7840: fix non-atomic allocation in write path
X-Git-Tag: firefly_0821_release~176^2~4^2~31^2~209
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=201cb6d48be510dba6161d56c1179a91684c6c5d;p=firefly-linux-kernel-4.4.55.git

USB: serial: mos7840: fix non-atomic allocation in write path

commit 3b7c7e52efda0d4640060de747768360ba70a7c0 upstream.

There is an allocation with GFP_KERNEL flag in mos7840_write(),
while it may be called from interrupt context.

Follow-up for commit 191252837626 ("USB: kobil_sct: fix non-atomic
allocation in write path")

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c
index 8ac9b55f05af..7f3ddd7ba2ce 100644
--- a/drivers/usb/serial/mos7840.c
+++ b/drivers/usb/serial/mos7840.c
@@ -1340,8 +1340,8 @@ static int mos7840_write(struct tty_struct *tty, struct usb_serial_port *port,
 	}
 
 	if (urb->transfer_buffer == NULL) {
-		urb->transfer_buffer =
-		    kmalloc(URB_TRANSFER_BUFFER_SIZE, GFP_KERNEL);
+		urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE,
+					       GFP_ATOMIC);
 		if (!urb->transfer_buffer)
 			goto exit;
 	}