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From: NeilBrown <neilb@suse.de>
To: Olivier Sobrie <olivier@sobrie.be>,
	"David S. Miller" <davem@davemloft.net>,
	Jan Dumon <j.dumon@option.com>
Cc: linux-usb@vger.kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	GTA04 owners <gta04-owner@goldelico.com>
Subject: [PATCH] hso: fix refcnt leak in recent patch.
Date: Tue, 14 Apr 2015 09:36:34 +1000	[thread overview]
Message-ID: <20150414093634.4fe24ba3@notabene.brown> (raw)

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Prior to
commit 29bd3bc1194c624ce863cab2a7da9bc1f0c3b47b
    hso: fix crash when device disappears while serial port is open

hso_serial_open would always kref_get(&serial->parent->ref) before
returning zero.
Since that commit, it only calls kref_get when returning 0 if
serial->port.count was zero.

This results in calls to
       kref_put(&serial->parent->ref, hso_serial_ref_free);

after hso_serial_ref_free has been called, which dereferences a freed
pointer.

This patch adds the missing kref_get().

Fixes: commit 29bd3bc1194c624ce863cab2a7da9bc1f0c3b47b
Cc: stable@vger.kernel.org (v4.0)
Cc: Olivier Sobrie <olivier@sobrie.be>
Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
index 75befc1bd816..6848fc903340 100644
--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c
@@ -1299,6 +1299,7 @@ static int hso_serial_open(struct tty_struct *tty, struct file *filp)
 		}
 	} else {
 		D1("Port was already open");
+		kref_get(&serial->parent->ref);
 	}
 
 	usb_autopm_put_interface(serial->parent->interface);

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             reply	other threads:[~2015-04-13 23:36 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-13 23:36 NeilBrown [this message]
     [not found] ` <20150414093634.4fe24ba3-wvvUuzkyo1EYVZTmpyfIwg@public.gmane.org>
2015-04-14  1:03   ` [PATCH] hso: fix refcnt leak in recent patch NeilBrown
     [not found]     ` <20150414110303.66edcfee-wvvUuzkyo1EYVZTmpyfIwg@public.gmane.org>
2015-04-14  6:50       ` Olivier Sobrie
2015-04-14  7:35         ` NeilBrown
2015-04-16 13:21     ` Olivier Sobrie

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