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Commit 88f4ea62 authored by Xiongfeng Wang's avatar Xiongfeng Wang Committed by Greg Kroah-Hartman
Browse files

hwrng: geode - Fix PCI device refcount leak 



[ Upstream commit 9f6ec8dc574efb7f4f3d7ee9cd59ae307e78f445 ]

for_each_pci_dev() is implemented by pci_get_device(). The comment of
pci_get_device() says that it will increase the reference count for the
returned pci_dev and also decrease the reference count for the input
pci_dev @from if it is not NULL.

If we break for_each_pci_dev() loop with pdev not NULL, we need to call
pci_dev_put() to decrease the reference count. We add a new struct
'amd_geode_priv' to record pointer of the pci_dev and membase, and then
add missing pci_dev_put() for the normal and error path.

Fixes: ef5d8627 ("[PATCH] Add Geode HW RNG driver")
Signed-off-by: default avatarXiongfeng Wang <wangxiongfeng2@huawei.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent f1c97f72

drivers/char/hw_random/geode-rng.c

+28 −8
Original line number Diff line number Diff line
@@ -51,6 +51,10 @@ static const struct pci_device_id pci_tbl[] = { 
};

MODULE_DEVICE_TABLE(pci, pci_tbl);



struct amd_geode_priv {

	struct pci_dev *pcidev;

	void __iomem *membase;

};



static int geode_rng_data_read(struct hwrng *rng, u32 *data)

{
@@ -90,6 +94,7 @@ static int __init mod_init(void) 
	const struct pci_device_id *ent;

	void __iomem *mem;

	unsigned long rng_base;

	struct amd_geode_priv *priv;



	for_each_pci_dev(pdev) {

		ent = pci_match_id(pci_tbl, pdev);
@@ -97,17 +102,26 @@ static int __init mod_init(void) 
			goto found;

	}

	/* Device not found. */

	goto out;

	return err;



found:

	priv = kzalloc(sizeof(*priv), GFP_KERNEL);

	if (!priv) {

		err = -ENOMEM;

		goto put_dev;

	}



	rng_base = pci_resource_start(pdev, 0);

	if (rng_base == 0)

		goto out;

		goto free_priv;

	err = -ENOMEM;

	mem = ioremap(rng_base, 0x58);

	if (!mem)

		goto out;

	geode_rng.priv = (unsigned long)mem;

		goto free_priv;



	geode_rng.priv = (unsigned long)priv;

	priv->membase = mem;

	priv->pcidev = pdev;



	pr_info("AMD Geode RNG detected\n");

	err = hwrng_register(&geode_rng);
@@ -116,20 +130,26 @@ static int __init mod_init(void) 
		       err);

		goto err_unmap;

	}

out:

	return err;



err_unmap:

	iounmap(mem);

	goto out;

free_priv:

	kfree(priv);

put_dev:

	pci_dev_put(pdev);

	return err;

}



static void __exit mod_exit(void)

{

	void __iomem *mem = (void __iomem *)geode_rng.priv;

	struct amd_geode_priv *priv;



	priv = (struct amd_geode_priv *)geode_rng.priv;

	hwrng_unregister(&geode_rng);

	iounmap(mem);

	iounmap(priv->membase);

	pci_dev_put(priv->pcidev);

	kfree(priv);

}



module_init(mod_init);