[PATCH] synclink_gt: add module_put on error path in hdlcdev_open()

From: Pavel Shved
Date: Fri Jun 17 2011 - 12:57:45 EST


hdlcdev_open() calls try_module_get, and does not put the module when
other functions subsequently called fail.

The patch adds an exit point in hdlcdev_open() that calls module_put()
after such errors.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Pavel Shved <shved@xxxxxxxxx>
---
drivers/tty/synclink_gt.c | 11 ++++++++---
1 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/synclink_gt.c b/drivers/tty/synclink_gt.c
index 18b48cd..e1e89a0 100644
--- a/drivers/tty/synclink_gt.c
+++ b/drivers/tty/synclink_gt.c
@@ -1542,14 +1542,15 @@ static int hdlcdev_open(struct net_device *dev)

/* generic HDLC layer open processing */
if ((rc = hdlc_open(dev)))
- return rc;
+ goto do_put;

/* arbitrate between network and tty opens */
spin_lock_irqsave(&info->netlock, flags);
if (info->port.count != 0 || info->netcount != 0) {
DBGINFO(("%s hdlc_open busy\n", dev->name));
spin_unlock_irqrestore(&info->netlock, flags);
- return -EBUSY;
+ rc = -EBUSY;
+ goto do_put;
}
info->netcount=1;
spin_unlock_irqrestore(&info->netlock, flags);
@@ -1559,7 +1560,7 @@ static int hdlcdev_open(struct net_device *dev)
spin_lock_irqsave(&info->netlock, flags);
info->netcount=0;
spin_unlock_irqrestore(&info->netlock, flags);
- return rc;
+ goto do_put;
}

/* assert DTR and RTS, apply hardware settings */
@@ -1579,6 +1580,10 @@ static int hdlcdev_open(struct net_device *dev)
else
netif_carrier_off(dev);
return 0;
+
+do_put:
+ module_put(THIS_MODULE);
+ return rc;
}

/**
--
1.7.0.2

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