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From:   Wenwen Wang <wenwen@cs.uga.edu>
To:     Wenwen Wang <wenwen@cs.uga.edu>
Cc:     Chas Williams <3chas3@gmail.com>,
        linux-atm-general@lists.sourceforge.net (moderated list:ATM),
        netdev@vger.kernel.org (open list:ATM),
        linux-kernel@vger.kernel.org (open list)
Subject: [PATCH] firestream: fix memory leaks
Date:   Sat, 25 Jan 2020 05:11:34 +0000
Message-Id: <20200125051134.11557-1-wenwen@cs.uga.edu>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

In fs_open(), 'vcc' is allocated through kmalloc() and assigned to
'atm_vcc->dev_data.' In the following execution, if there is no more free
channel, the error code EBUSY will be returned. However, 'vcc' is not
deallocated, leading to memory leaks. Note that, in normal cases where
fs_open() returns 0, 'vcc' will be deallocated in fs_close(). But, if
fs_open() fails, there is no guarantee that fs_close() will be invoked.

To fix this issue, deallocate 'vcc' before EBUSY is returned.

Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
---
 drivers/atm/firestream.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/atm/firestream.c b/drivers/atm/firestream.c
index aad00d2b28f5..093712e34de7 100644
--- a/drivers/atm/firestream.c
+++ b/drivers/atm/firestream.c
@@ -912,6 +912,7 @@ static int fs_open(struct atm_vcc *atm_vcc)
 			}
 			if (!to) {
 				printk ("No more free channels for FS50..\n");
+				kfree(vcc);
 				return -EBUSY;
 			}
 			vcc->channo = dev->channo;
@@ -922,6 +923,7 @@ static int fs_open(struct atm_vcc *atm_vcc)
 			if (((DO_DIRECTION(rxtp) && dev->atm_vccs[vcc->channo])) ||
 			    ( DO_DIRECTION(txtp) && test_bit (vcc->channo, dev->tx_inuse))) {
 				printk ("Channel is in use for FS155.\n");
+				kfree(vcc);
 				return -EBUSY;
 			}
 		}
-- 
2.17.1