[PATCH 4.7 127/143] USB: serial: mos7840: fix non-atomic allocation in write path

From: Greg Kroah-Hartman
Date: Mon Sep 05 2016 - 12:57:19 EST


4.7-stable review patch. If anyone has any objections, please let me know.

------------------

From: Alexey Khoroshilov <khoroshilov@xxxxxxxxx>

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@xxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/usb/serial/mos7840.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/usb/serial/mos7840.c
+++ b/drivers/usb/serial/mos7840.c
@@ -1340,8 +1340,8 @@ static int mos7840_write(struct tty_stru
}

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;
}