When igc_led_setup() fails, igc_probe() fails and triggers kernel panic in free_netdev() since unregister_netdev() is not called. [1] This behavior can be tested using fault-injection framework, especially the failslab feature. [2] Since LED support is not mandatory, treat LED setup failures as non-fatal and continue probe with a warning message, consequently avoiding the kernel panic. [1] kernel BUG at net/core/dev.c:12047! Oops: invalid opcode: 0000 [#1] SMP NOPTI CPU: 0 UID: 0 PID: 937 Comm: repro-igc-led-e Not tainted 6.17.0-rc4-enjuk-tnguy-00865-gc4940196ab02 #64 PREEMPT(voluntary) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:free_netdev+0x278/0x2b0 [...] Call Trace: igc_probe+0x370/0x910 local_pci_probe+0x3a/0x80 pci_device_probe+0xd1/0x200 [...] [2] #!/bin/bash -ex FAILSLAB_PATH=/sys/kernel/debug/failslab/ DEVICE=0000:00:05.0 START_ADDR=$(grep " igc_led_setup" /proc/kallsyms \ | awk '{printf("0x%s", $1)}') END_ADDR=$(printf "0x%x" $((START_ADDR + 0x100))) echo $START_ADDR > $FAILSLAB_PATH/require-start echo $END_ADDR > $FAILSLAB_PATH/require-end echo 1 > $FAILSLAB_PATH/times echo 100 > $FAILSLAB_PATH/probability echo N > $FAILSLAB_PATH/ignore-gfp-wait echo $DEVICE > /sys/bus/pci/drivers/igc/bind Fixes: ea578703b03d ("igc: Add support for LEDs on i225/i226") Signed-off-by: Kohei Enju --- Changes: v1->v2: - don't fail probe when led setup fails - rephrase subject and commit message v1: https://lore.kernel.org/intel-wired-lan/20250906055239.29396-1-enjuk@amazon.com/ --- drivers/net/ethernet/intel/igc/igc.h | 1 + drivers/net/ethernet/intel/igc/igc_main.c | 12 +++++++++--- 2 files changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h index 266bfcf2a28f..a427f05814c1 100644 --- a/drivers/net/ethernet/intel/igc/igc.h +++ b/drivers/net/ethernet/intel/igc/igc.h @@ -345,6 +345,7 @@ struct igc_adapter { /* LEDs */ struct mutex led_mutex; struct igc_led_classdev *leds; + bool leds_available; }; void igc_up(struct igc_adapter *adapter); diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c index e79b14d50b24..728d7ca5338b 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -7335,8 +7335,14 @@ static int igc_probe(struct pci_dev *pdev, if (IS_ENABLED(CONFIG_IGC_LEDS)) { err = igc_led_setup(adapter); - if (err) - goto err_register; + if (err) { + netdev_warn_once(netdev, + "LED init failed (%d); continuing without LED support\n", + err); + adapter->leds_available = false; + } else { + adapter->leds_available = true; + } } return 0; @@ -7392,7 +7398,7 @@ static void igc_remove(struct pci_dev *pdev) cancel_work_sync(&adapter->watchdog_task); hrtimer_cancel(&adapter->hrtimer); - if (IS_ENABLED(CONFIG_IGC_LEDS)) + if (IS_ENABLED(CONFIG_IGC_LEDS) && adapter->leds_available) igc_led_free(adapter); /* Release control of h/w to f/w. If f/w is AMT enabled, this -- 2.48.1