From daf82bd24e308c5a83758047aff1bd81edda4f11 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20Miros=C5=82aw?= <mirq-linux@rere.qmqm.pl>
Date: Sat, 10 Aug 2019 10:42:48 +0200
Subject: [PATCH] usb: gadget: u_serial: add missing port entry locking
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Git-commit: daf82bd24e308c5a83758047aff1bd81edda4f11
Patch-mainline: v5.5-rc1
References: bsc#1051510
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>
Tested-by: Ladislav Michl <ladis@linux-mips.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/usb/gadget/function/u_serial.c | 2 ++
1 file changed, 2 insertions(+)
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;
}
--
2.16.4