From 183a45087d126d126e8dd1d9b2602fc129dff9ad Mon Sep 17 00:00:00 2001
From: Johan Hovold <jhovold@gmail.com>
Date: Mon, 26 May 2014 19:23:41 +0200
Subject: [PATCH] USB: cdc-acm: fix potential urb leak and PM imbalance in
write
Make sure to check return value of autopm get in write() in order to
avoid urb leak and PM counter imbalance on errors.
Fixes: 11ea859d64b6 ("USB: additional power savings for cdc-acm devices
that support remote wakeup")
Cc: <stable@vger.kernel.org> # v2.6.27
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/class/cdc-acm.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 1ac6c5dda9f7..c255e77282ad 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -668,7 +668,13 @@ static int acm_tty_write(struct tty_struct *tty,
memcpy(wb->buf, buf, count);
wb->len = count;
- usb_autopm_get_interface_async(acm->control);
+ stat = usb_autopm_get_interface_async(acm->control);
+ if (stat) {
+ wb->use = 0;
+ spin_unlock_irqrestore(&acm->write_lock, flags);
+ return stat;
+ }
+
if (acm->susp_count) {
usb_anchor_urb(wb->urb, &acm->delayed);
spin_unlock_irqrestore(&acm->write_lock, flags);
--
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