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>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c
index 80fc40a..59fdb84 100644 (file)
--- a/drivers/usb/serial/mos7840.c
+++ b/drivers/usb/serial/mos7840.c
@@ -1524,8 +1524,8 @@ 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 == NULL) {
                        dev_err(&port->dev, "%s no more kernel memory...\n",