| Message ID | 20221123093949.115579-1-wangxiongfeng2@huawei.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | hwrng: amd - Fix PCI device refcount leak | expand |
On Wed, Nov 23, 2022 at 05:39:49PM +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 the normal and error path. > > Fixes: 96d63c0297cc ("[PATCH] Add AMD HW RNG driver") > Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> > --- > drivers/char/hw_random/amd-rng.c | 18 +++++++++++++----- > 1 file changed, 13 insertions(+), 5 deletions(-) The driver geode-rng seems to have the same problem, could you please fix that as well? Thanks,
On Wed, Nov 23, 2022 at 05:39:49PM +0800, Xiongfeng Wang wrote: > > @@ -201,6 +207,8 @@ static void __exit amd_rng_mod_exit(void) > release_region(priv->pmbase + PMBASE_OFFSET, PMBASE_SIZE); > > kfree(priv); > + > + pci_dev_put(priv->pcidev); Oops, this doesn't look right. Please fix and resubmit. Thanks,
On 2022/12/2 17:43, Herbert Xu wrote: > On Wed, Nov 23, 2022 at 05:39:49PM +0800, Xiongfeng Wang wrote: >> >> @@ -201,6 +207,8 @@ static void __exit amd_rng_mod_exit(void) >> release_region(priv->pmbase + PMBASE_OFFSET, PMBASE_SIZE); >> >> kfree(priv); >> + >> + pci_dev_put(priv->pcidev); > > Oops, this doesn't look right. Please fix and resubmit. Ah, Sorry, my mistake! I will send another version with the fix of geode-rng. Thanks, Xiongfeng > > Thanks, >
diff --git a/drivers/char/hw_random/amd-rng.c b/drivers/char/hw_random/amd-rng.c index c22d4184bb61..46e997366b15 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; } @@ -201,6 +207,8 @@ static void __exit amd_rng_mod_exit(void) release_region(priv->pmbase + PMBASE_OFFSET, PMBASE_SIZE); kfree(priv); + + pci_dev_put(priv->pcidev); } module_init(amd_rng_mod_init);
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 <wangxiongfeng2@huawei.com> --- drivers/char/hw_random/amd-rng.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-)