diff mbox series

[v3,1/5] usb: gadget: u_serial: add missing port entry locking

Message ID 7e94cf9d80899fe76537b455bb5668cc7ed0fa08.1551264094.git.mirq-linux@rere.qmqm.pl (mailing list archive)
State New, archived
Headers show
Series usb: gadget: u_serial: console for multiple ports | expand

Commit Message

Michał Mirosław Feb. 27, 2019, 10:46 a.m. UTC 
gserial_alloc_line() misses locking (for a release barrier) while
resetting port entry on TTY allocation failure. Fix this.

Cc: stable@vger.kernel.org
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>

---
  v3: added cc-stable
  v2: no changes
---
 drivers/usb/gadget/function/u_serial.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Greg KH Feb. 27, 2019, 1:03 p.m. UTC | #1 
On Wed, Feb 27, 2019 at 11:46:57AM +0100, Michał Mirosław wrote:
> gserial_alloc_line() misses locking (for a release barrier) while
> resetting port entry on TTY allocation failure. Fix this.
> 
> Cc: stable@vger.kernel.org
> Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
> 

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff mbox series

Patch

diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c
index 65f634ec7fc2..bb1e2e1d0076 100644
--- a/drivers/usb/gadget/function/u_serial.c
+++ b/drivers/usb/gadget/function/u_serial.c
@@ -1239,8 +1239,10 @@  int gserial_alloc_line(unsigned char *line_num)
 				__func__, port_num, PTR_ERR(tty_dev));
 
 		ret = PTR_ERR(tty_dev);
+		mutex_lock(&ports[port_num].lock);
 		port = ports[port_num].port;
 		ports[port_num].port = NULL;
+		mutex_unlock(&ports[port_num].lock);
 		gserial_free_port(port);
 		goto err;
 	}