Re: [PATCH] net: phy: phy_led_triggers: Fix a possible null-pointer dereference in phy_led_trigger_change_speed()

[Jia-Ju Bai]

On 2019/7/29 21:45, Andrew Lunn wrote:

On Mon, Jul 29, 2019 at 05:24:24PM +0800, Jia-Ju Bai wrote:

In phy_led_trigger_change_speed(), there is an if statement on line 48
to check whether phy->last_triggered is NULL:
     if (!phy->last_triggered)

When phy->last_triggered is NULL, it is used on line 52:
     led_trigger_event(&phy->last_triggered->trigger, LED_OFF);

Thus, a possible null-pointer dereference may occur.

To fix this bug, led_trigger_event(&phy->last_triggered->trigger,
LED_OFF) is called when phy->last_triggered is not NULL.

This bug is found by a static analysis tool STCheck written by us.

Who is 'us'?

Me and my colleague...


Best wishes,
Jia-Ju Bai