[PATCH net-next] r8169: keep LED device name valid after setup
From: Zhixing Chen <hidden>
Date: 2026-08-13 10:08:15
Subsystem:
8169 10/100/1000 gigabit ethernet driver, networking drivers, the rest · Maintainers:
Heiner Kallweit, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
rtl8168_setup_ldev() and rtl8125_setup_led_ldev() build the LED device name in a stack buffer and assign it to led_cdev->name. The LED class device registration path reads led_cdev->name after it has been assigned, and struct led_classdev stores the name as part of the LED class device state. Do not keep a pointer to a setup function's stack buffer there. Store the name in struct r8169_led_classdev instead, so it remains valid for the lifetime of the LED class device. Signed-off-by: Zhixing Chen <redacted> --- I noticed this while reviewing the r8169 driver code. The LED name is stored in led_cdev->name, but the current buffer lifetime does not match the LED class device lifetime. I have not seen a crash from this, but led_cdev->name points to a stack buffer after setup returns. Storing the name in the per-LED private object keeps the pointer lifetime aligned with the LED class device. --- drivers/net/ethernet/realtek/r8169_leds.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/drivers/net/ethernet/realtek/r8169_leds.c b/drivers/net/ethernet/realtek/r8169_leds.c
index 1999e81f0bca..5a2067be3095 100644
--- a/drivers/net/ethernet/realtek/r8169_leds.c
+++ b/drivers/net/ethernet/realtek/r8169_leds.c@@ -31,6 +31,7 @@ struct r8169_led_classdev { struct led_classdev led; struct net_device *ndev; int index; + char name[LED_MAX_NAME_SIZE]; }; #define lcdev_to_r8169_ldev(lcdev) container_of(lcdev, struct r8169_led_classdev, led)
@@ -131,13 +132,12 @@ static void rtl8168_setup_ldev(struct r8169_led_classdev *ldev, { struct rtl8169_private *tp = netdev_priv(ndev); struct led_classdev *led_cdev = &ldev->led; - char led_name[LED_MAX_NAME_SIZE]; ldev->ndev = ndev; ldev->index = index; - r8169_get_led_name(tp, index, led_name, LED_MAX_NAME_SIZE); - led_cdev->name = led_name; + r8169_get_led_name(tp, index, ldev->name, sizeof(ldev->name)); + led_cdev->name = ldev->name; led_cdev->hw_control_trigger = "netdev"; led_cdev->flags |= LED_RETAIN_AT_SHUTDOWN; led_cdev->hw_control_is_supported = rtl8168_led_hw_control_is_supported;
@@ -230,13 +230,12 @@ static void rtl8125_setup_led_ldev(struct r8169_led_classdev *ldev, { struct rtl8169_private *tp = netdev_priv(ndev); struct led_classdev *led_cdev = &ldev->led; - char led_name[LED_MAX_NAME_SIZE]; ldev->ndev = ndev; ldev->index = index; - r8169_get_led_name(tp, index, led_name, LED_MAX_NAME_SIZE); - led_cdev->name = led_name; + r8169_get_led_name(tp, index, ldev->name, sizeof(ldev->name)); + led_cdev->name = ldev->name; led_cdev->hw_control_trigger = "netdev"; led_cdev->flags |= LED_RETAIN_AT_SHUTDOWN; led_cdev->hw_control_is_supported = rtl8125_led_hw_control_is_supported;
base-commit: f6057f06ef7afa9893ed33603f7917fa39d237b5 -- 2.34.1