Thread (10 messages) 10 messages, 2 authors, 2024-10-20

Re: [PATCH 5/6] phy: core: Add missing of_node_put() in of_phy_provider_lookup()

From: Christophe JAILLET <hidden>
Date: 2024-10-20 12:51:48
Also in: linux-pci, linux-phy, lkml, stable

Le 20/10/2024 à 07:27, Zijun Hu a écrit :
quoted hunk ↗ jump to hunk
From: Zijun Hu <redacted>

The for_each_child_of_node() macro automatically decrements the child
refcount at the end of every iteration. On early exits, of_node_put()
must be used to manually decrement the refcount and avoid memory leaks.

The macro called by of_phy_provider_lookup() has such early exit, but
it does not call of_node_put() before early exit.

Fixed by adding missing of_node_put() in of_phy_provider_lookup().

Fixes: 2a4c37016ca9 ("phy: core: Fix of_phy_provider_lookup to return PHY provider for sub node")
Cc: stable@vger.kernel.org
Signed-off-by: Zijun Hu <redacted>

---
The impact of this change is wide since of_phy_provider_lookup()
is indirectly called by APIs phy_get(), of_phy_get(), and
devm_of_phy_get_by_index().

The following kernel mainline commit has similar fix:
Commit: b337cc3ce475 ("backlight: lm3509_bl: Fix early returns in for_each_child_of_node()")
---
  drivers/phy/phy-core.c | 5 +++--
  1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
index 967878b78797..24bd619a33dd 100644
--- a/drivers/phy/phy-core.c
+++ b/drivers/phy/phy-core.c
@@ -143,10 +143,11 @@ static struct phy_provider *of_phy_provider_lookup(struct device_node *node)
  	list_for_each_entry(phy_provider, &phy_provider_list, list) {
  		if (phy_provider->dev->of_node == node)
  			return phy_provider;
-
  		for_each_child_of_node(phy_provider->children, child)
-			if (child == node)
+			if (child == node) {
+				of_node_put(child);
  				return phy_provider;
+			}
Hi,

Maybe for_each_child_of_node_scoped() to slightly simplify things at the 
same time?
  	}
  
  	return ERR_PTR(-EPROBE_DEFER);
  
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