[net PATCH v2] net: phy: Remove LED entry from LEDs list on unregister

[net PATCH v2] net: phy: Remove LED entry from LEDs list on unregister

[Christian Marangi]

Commit c938ab4da0eb ("net: phy: Manual remove LEDs to ensure correct
ordering") correctly fixed a problem with using devm_ but missed
removing the LED entry from the LEDs list.

This cause kernel panic on specific scenario where the port for the PHY
is torn down and up and the kmod for the PHY is removed.

On setting the port down the first time, the assosiacted LEDs are
correctly unregistered. The associated kmod for the PHY is now removed.
The kmod is now added again and the port is now put up, the associated LED
are registered again.
On putting the port down again for the second time after these step, the
LED list now have 4 elements. With the first 2 already unregistered
previously and the 2 new one registered again.

This cause a kernel panic as the first 2 element should have been
removed.

Fix this by correctly removing the element when LED is unregistered.

Reported-by: Daniel Golle <daniel@makrotopia.org>
Tested-by: Daniel Golle <daniel@makrotopia.org>
Cc: stable@vger.kernel.org
Fixes: c938ab4da0eb ("net: phy: Manual remove LEDs to ensure correct ordering")
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
Changes v2:
- Drop second patch
- Add Reviewed-by tag

 drivers/net/phy/phy_device.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 560e338b307a..499797646580 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -3326,10 +3326,11 @@ static __maybe_unused int phy_led_hw_is_supported(struct led_classdev *led_cdev,
 
 static void phy_leds_unregister(struct phy_device *phydev)
 {
-	struct phy_led *phyled;
+	struct phy_led *phyled, *tmp;
 
-	list_for_each_entry(phyled, &phydev->leds, list) {
+	list_for_each_entry_safe(phyled, tmp, &phydev->leds, list) {
 		led_classdev_unregister(&phyled->led_cdev);
+		list_del(&phyled->list);
 	}
 }
 
-- 
2.45.2

Re: [net PATCH v2] net: phy: Remove LED entry from LEDs list on unregister

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Fri,  4 Oct 2024 20:27:58 +0200 you wrote:
> Commit c938ab4da0eb ("net: phy: Manual remove LEDs to ensure correct
> ordering") correctly fixed a problem with using devm_ but missed
> removing the LED entry from the LEDs list.
> 
> This cause kernel panic on specific scenario where the port for the PHY
> is torn down and up and the kmod for the PHY is removed.
> 
> [...]

Here is the summary with links:
  - [net,v2] net: phy: Remove LED entry from LEDs list on unregister
    https://git.kernel.org/netdev/net/c/f50b5d74c68e

You are awesome, thank you!
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