Patch "hwrng: amd - Fix PCI device refcount leak" has been added to the 6.0-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    hwrng: amd - Fix PCI device refcount leak

to the 6.0-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     hwrng-amd-fix-pci-device-refcount-leak.patch
and it can be found in the queue-6.0 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 83aa369fd8afa2f0720d2176be86c98cecc952d6
Author: Xiongfeng Wang <wangxiongfeng2@xxxxxxxxxx>
Date:   Fri Dec 2 21:22:33 2022 +0800

    hwrng: amd - Fix PCI device refcount leak
    
    [ Upstream commit ecadb5b0111ea19fc7c240bb25d424a94471eb7d ]
    
    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@xxxxxxxxxx>
    Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

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);
 }