Commit 271da132 authored Jul 30, 2019 by Jia-Ju Bai Committed by David S. Miller Jul 31, 2019

net: phy: phy_led_triggers: Fix a possible null-pointer dereference in...


net: phy: phy_led_triggers: Fix a possible null-pointer dereference in phy_led_trigger_change_speed()

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
the OSLAB group in Tsinghua University.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent e29903c4

drivers/net/phy/phy_led_triggers.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -48,8 +48,9 @@ void phy_led_trigger_change_speed(struct phy_device *phy)
		if (!phy->last_triggered)
		led_trigger_event(&phy->led_link_trigger->trigger,
		LED_FULL);

		else
		led_trigger_event(&phy->last_triggered->trigger, LED_OFF);

		led_trigger_event(&plt->trigger, LED_FULL);
		phy->last_triggered = plt;
		}

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