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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Qiushi Wu <wu000273@umn.edu>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.8 040/255] PCI: Fix pci_create_slot() reference count leak
Date:   Tue,  1 Sep 2020 17:08:16 +0200
Message-Id: <20200901151002.671774167@linuxfoundation.org>
In-Reply-To: <20200901151000.800754757@linuxfoundation.org>
References: <20200901151000.800754757@linuxfoundation.org>
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From: Qiushi Wu <wu000273@umn.edu>

[ Upstream commit 8a94644b440eef5a7b9c104ac8aa7a7f413e35e5 ]

kobject_init_and_add() takes a reference even when it fails.  If it returns
an error, kobject_put() must be called to clean up the memory associated
with the object.

When kobject_init_and_add() fails, call kobject_put() instead of kfree().

b8eb718348b8 ("net-sysfs: Fix reference count leak in
rx|netdev_queue_add_kobject") fixed a similar problem.

Link: https://lore.kernel.org/r/20200528021322.1984-1-wu000273@umn.edu
Signed-off-by: Qiushi Wu <wu000273@umn.edu>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/pci/slot.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/slot.c b/drivers/pci/slot.c
index cc386ef2fa122..3861505741e6d 100644
--- a/drivers/pci/slot.c
+++ b/drivers/pci/slot.c
@@ -268,13 +268,16 @@ placeholder:
 	slot_name = make_slot_name(name);
 	if (!slot_name) {
 		err = -ENOMEM;
+		kfree(slot);
 		goto err;
 	}
 
 	err = kobject_init_and_add(&slot->kobj, &pci_slot_ktype, NULL,
 				   "%s", slot_name);
-	if (err)
+	if (err) {
+		kobject_put(&slot->kobj);
 		goto err;
+	}
 
 	INIT_LIST_HEAD(&slot->list);
 	list_add(&slot->list, &parent->slots);
@@ -293,7 +296,6 @@ out:
 	mutex_unlock(&pci_slot_mutex);
 	return slot;
 err:
-	kfree(slot);
 	slot = ERR_PTR(err);
 	goto out;
 }
-- 
2.25.1