2022-12-02 13:10:41

by Xiongfeng Wang

Subject: [PATCH v2 0/2] hwrng: Fix PCI device refcount leak

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. Add the missing
pci_dev_put() for amd-hwrng and geode-hwrng.


ChangeLog:
v1 -> v2:
1. fix error in amd_rng_mod_exit()
2. also add refcount leak fix for geode-hwrng

Xiongfeng Wang (2):
hwrng: amd - Fix PCI device refcount leak
hwrng: geode - Fix PCI device refcount leak

drivers/char/hw_random/amd-rng.c | 18 ++++++++++-----
drivers/char/hw_random/geode-rng.c | 36 +++++++++++++++++++++++-------
2 files changed, 41 insertions(+), 13 deletions(-)

--
2.20.1

2022-12-02 13:13:40

by Xiongfeng Wang

Subject: [PATCH v2 1/2] hwrng: amd - Fix PCI device refcount leak

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. Add the missing
pci_dev_put() for the normal and error path.

Fixes: 96d63c0297cc ("[PATCH] Add AMD HW RNG driver")
Signed-off-by: Xiongfeng Wang <[email protected]>
---
drivers/char/hw_random/amd-rng.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/char/hw_random/amd-rng.c b/drivers/char/hw_random/amd-rng.c
index c22d4184bb61..0555e3838bce 100644
--- a/drivers/char/hw_random/amd-rng.c
+++ b/drivers/char/hw_random/amd-rng.c
@@ -143,15 +143,19 @@ static int __init amd_rng_mod_init(void)
found:
err = pci_read_config_dword(pdev, 0x58, &pmbase);
if (err)
- return err;
+ goto put_dev;

pmbase &= 0x0000FF00;
- if (pmbase == 0)
- return -EIO;
+ if (pmbase == 0) {
+ err = -EIO;
+ goto put_dev;
+ }

priv = kzalloc(sizeof(*priv), GFP_KERNEL);
- if (!priv)
- return -ENOMEM;
+ if (!priv) {
+ err = -ENOMEM;
+ goto put_dev;
+ }

if (!request_region(pmbase + PMBASE_OFFSET, PMBASE_SIZE, DRV_NAME)) {
dev_err(&pdev->dev, DRV_NAME " region 0x%x already in use!\n",
@@ -185,6 +189,8 @@ static int __init amd_rng_mod_init(void)
release_region(pmbase + PMBASE_OFFSET, PMBASE_SIZE);
out:
kfree(priv);
+put_dev:
+ pci_dev_put(pdev);
return err;
}

@@ -200,6 +206,8 @@ static void __exit amd_rng_mod_exit(void)

release_region(priv->pmbase + PMBASE_OFFSET, PMBASE_SIZE);

+ pci_dev_put(priv->pcidev);
+
kfree(priv);
}

--
2.20.1

2022-12-09 11:15:49

by Herbert Xu

Subject: Re: [PATCH v2 0/2] hwrng: Fix PCI device refcount leak

On Fri, Dec 02, 2022 at 09:22:32PM +0800, Xiongfeng Wang wrote:
> 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. Add the missing
> pci_dev_put() for amd-hwrng and geode-hwrng.
>
>
> ChangeLog:
> v1 -> v2:
> 1. fix error in amd_rng_mod_exit()
> 2. also add refcount leak fix for geode-hwrng
>
> Xiongfeng Wang (2):
> hwrng: amd - Fix PCI device refcount leak
> hwrng: geode - Fix PCI device refcount leak
>
> drivers/char/hw_random/amd-rng.c | 18 ++++++++++-----
> drivers/char/hw_random/geode-rng.c | 36 +++++++++++++++++++++++-------
> 2 files changed, 41 insertions(+), 13 deletions(-)
>
> --
> 2.20.1

All applied. Thanks.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt