linux-kernel - [PATCH] usb: phy: Initialize struct usb_phy list

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Message-Id: <20251113-diogo-smaug_typec-v1-1-f1aa3b48620d@tecnico.ulisboa.pt>
Date: Thu, 13 Nov 2025 14:59:06 +0000
From: Diogo Ivo <diogo.ivo@...nico.ulisboa.pt>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>, 
 Felipe Balbi <felipe.balbi@...ux.intel.com>, 
 Baolin Wang <baolin.wang@...ux.alibaba.com>
Cc: linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org, 
 stable@...r.kernel.org, Diogo Ivo <diogo.ivo@...nico.ulisboa.pt>
Subject: [PATCH] usb: phy: Initialize struct usb_phy list_head

When executing usb_add_phy() and usb_add_phy_dev() it is possible that
usb_add_extcon() fails (for example with -EPROBE_DEFER), in which case
the usb_phy does not get added to phy_list via
list_add_tail(&x->head, phy_list).

Then, when the driver that tried to add the phy receives the error
propagated from usb_add_extcon() and calls into usb_remove_phy() to
undo the partial registration there will be an unconditional call to
list_del(&x->head) which is notinitialized and leads to a NULL pointer
dereference.

Fix this by initializing x->head before usb_add_extcon() has a chance to
fail.

Fixes: 7d21114dc6a2d53 ("usb: phy: Introduce one extcon device into usb phy")
Cc: stable@...r.kernel.org
Signed-off-by: Diogo Ivo <diogo.ivo@...nico.ulisboa.pt>
---
 drivers/usb/phy/phy.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/usb/phy/phy.c b/drivers/usb/phy/phy.c
index e1435bc59662..5a9b9353f343 100644
--- a/drivers/usb/phy/phy.c
+++ b/drivers/usb/phy/phy.c
@@ -646,6 +646,8 @@ int usb_add_phy(struct usb_phy *x, enum usb_phy_type type)
 		return -EINVAL;
 	}
 
+	INIT_LIST_HEAD(&x->head);
+
 	usb_charger_init(x);
 	ret = usb_add_extcon(x);
 	if (ret)
@@ -696,6 +698,8 @@ int usb_add_phy_dev(struct usb_phy *x)
 		return -EINVAL;
 	}
 
+	INIT_LIST_HEAD(&x->head);
+
 	usb_charger_init(x);
 	ret = usb_add_extcon(x);
 	if (ret)

---
base-commit: 35d084745b3ea4af571ed421844f2bb1a99ad6e2
change-id: 20251113-diogo-smaug_typec-56b2059b892b

Best regards,
-- 
Diogo Ivo <diogo.ivo@...nico.ulisboa.pt>