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From:   Qinglang Miao <miaoqinglang@huawei.com>
To:     Bjorn Helgaas <bhelgaas@google.com>
CC:     <linux-pci@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        Qinglang Miao <miaoqinglang@huawei.com>
Subject: [PATCH] PCI: fix use-after-free in pci_register_host_bridge
Date:   Fri, 20 Nov 2020 15:48:48 +0800
Message-ID: <20201120074848.31418-1-miaoqinglang@huawei.com>
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Precedence: bulk

When put_device(&bridge->dev) being called, kfree(bridge) is inside
of release function, so the following device_del would cause a
use-after-free bug.

Fixes: 37d6a0a6f470 ("PCI: Add pci_register_host_bridge() interface")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
---
 drivers/pci/probe.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 4289030b0..82292e87e 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -991,8 +991,8 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
 	return 0;
 
 unregister:
-	put_device(&bridge->dev);
 	device_del(&bridge->dev);
+	put_device(&bridge->dev);
 
 free:
 	kfree(bus);
-- 
2.23.0