FAILED: patch "[PATCH] power: supply: twl4030-charger: fix OF sibling-node lookup" failed to apply to 4.9-stable tree

FAILED: patch "[PATCH] power: supply: twl4030-charger: fix OF sibling-node lookup" failed to apply to 4.9-stable tree

[gregkh]

The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From 9844fb2e351311210e6660a9a1c62d17424a6145 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Mon, 27 Aug 2018 10:21:53 +0200
Subject: [PATCH] power: supply: twl4030-charger: fix OF sibling-node lookup

Use the new of_get_compatible_child() helper to lookup the usb sibling
node instead of using of_find_compatible_node(), which searches the
entire tree from a given start node and thus can return an unrelated
(non-sibling) node.

This also addresses a potential use-after-free (e.g. after probe
deferral) as the tree-wide helper drops a reference to its first
argument (i.e. the parent device node).

While at it, also fix the related phy-node reference leak.

Fixes: f5e4edb8c888 ("power: twl4030_charger: find associated phy by more reliable means.")
Cc: stable <stable@vger.kernel.org>     # 4.2
Cc: NeilBrown <neilb@suse.de>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: Sebastian Reichel <sre@kernel.org>
Reviewed-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>

diff --git a/drivers/power/supply/twl4030_charger.c b/drivers/power/supply/twl4030_charger.c
index bbcaee56db9d..b6a7d9f74cf3 100644
--- a/drivers/power/supply/twl4030_charger.c
+++ b/drivers/power/supply/twl4030_charger.c
@@ -996,12 +996,13 @@ static int twl4030_bci_probe(struct platform_device *pdev)
 	if (bci->dev->of_node) {
 		struct device_node *phynode;
 
-		phynode = of_find_compatible_node(bci->dev->of_node->parent,
-						  NULL, "ti,twl4030-usb");
+		phynode = of_get_compatible_child(bci->dev->of_node->parent,
+						  "ti,twl4030-usb");
 		if (phynode) {
 			bci->usb_nb.notifier_call = twl4030_bci_usb_ncb;
 			bci->transceiver = devm_usb_get_phy_by_node(
 				bci->dev, phynode, &bci->usb_nb);
+			of_node_put(phynode);
 			if (IS_ERR(bci->transceiver)) {
 				ret = PTR_ERR(bci->transceiver);
 				if (ret == -EPROBE_DEFER)

Re: FAILED: patch "[PATCH] power: supply: twl4030-charger: fix OF sibling-node lookup" failed to apply to 4.9-stable tree

[Johan Hovold]

On Sat, Nov 10, 2018 at 06:02:41PM -0800, Greg Kroah-Hartman wrote:
> 
> The patch below does not apply to the 4.9-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.

This one also depends on

	36156f9241cb ("of: add helper to lookup compatible child node")

Johan

> ------------------ original commit in Linus's tree ------------------
> 
> From 9844fb2e351311210e6660a9a1c62d17424a6145 Mon Sep 17 00:00:00 2001
> From: Johan Hovold <johan@kernel.org>
> Date: Mon, 27 Aug 2018 10:21:53 +0200
> Subject: [PATCH] power: supply: twl4030-charger: fix OF sibling-node lookup
> 
> Use the new of_get_compatible_child() helper to lookup the usb sibling
> node instead of using of_find_compatible_node(), which searches the
> entire tree from a given start node and thus can return an unrelated
> (non-sibling) node.
> 
> This also addresses a potential use-after-free (e.g. after probe
> deferral) as the tree-wide helper drops a reference to its first
> argument (i.e. the parent device node).
> 
> While at it, also fix the related phy-node reference leak.
> 
> Fixes: f5e4edb8c888 ("power: twl4030_charger: find associated phy by more reliable means.")
> Cc: stable <stable@vger.kernel.org>     # 4.2
> Cc: NeilBrown <neilb@suse.de>
> Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
> Cc: Sebastian Reichel <sre@kernel.org>
> Reviewed-by: Sebastian Reichel <sre@kernel.org>
> Signed-off-by: Johan Hovold <johan@kernel.org>
> Signed-off-by: Rob Herring <robh@kernel.org>
> 
> diff --git a/drivers/power/supply/twl4030_charger.c b/drivers/power/supply/twl4030_charger.c
> index bbcaee56db9d..b6a7d9f74cf3 100644
> --- a/drivers/power/supply/twl4030_charger.c
> +++ b/drivers/power/supply/twl4030_charger.c
> @@ -996,12 +996,13 @@ static int twl4030_bci_probe(struct platform_device *pdev)
>  	if (bci->dev->of_node) {
>  		struct device_node *phynode;
>  
> -		phynode = of_find_compatible_node(bci->dev->of_node->parent,
> -						  NULL, "ti,twl4030-usb");
> +		phynode = of_get_compatible_child(bci->dev->of_node->parent,
> +						  "ti,twl4030-usb");
>  		if (phynode) {
>  			bci->usb_nb.notifier_call = twl4030_bci_usb_ncb;
>  			bci->transceiver = devm_usb_get_phy_by_node(
>  				bci->dev, phynode, &bci->usb_nb);
> +			of_node_put(phynode);
>  			if (IS_ERR(bci->transceiver)) {
>  				ret = PTR_ERR(bci->transceiver);
>  				if (ret == -EPROBE_DEFER)
>