This is a note to let you know that I've just added the patch titled HID: bigben: use spinlock to safely schedule workers to the 6.2-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: hid-bigben-use-spinlock-to-safely-schedule-workers.patch and it can be found in the queue-6.2 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit a84612e0dc75c6b741ae65227b6a4c84dd5d18c7 Author: Pietro Borrello <borrello@xxxxxxxxxxxxxxxx> Date: Sun Feb 12 19:00:01 2023 +0000 HID: bigben: use spinlock to safely schedule workers [ Upstream commit 76ca8da989c7d97a7f76c75d475fe95a584439d7 ] Use spinlocks to deal with workers introducing a wrapper bigben_schedule_work(), and several spinlock checks. Otherwise, bigben_set_led() may schedule bigben->worker after the structure has been freed, causing a use-after-free. Fixes: 4eb1b01de5b9 ("HID: hid-bigbenff: fix race condition for scheduled work during removal") Signed-off-by: Pietro Borrello <borrello@xxxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20230125-hid-unregister-leds-v4-3-7860c5763c38@xxxxxxxxxxxxxxxx Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/hid/hid-bigbenff.c b/drivers/hid/hid-bigbenff.c index b98c5f31c184b..9d6560db762b1 100644 --- a/drivers/hid/hid-bigbenff.c +++ b/drivers/hid/hid-bigbenff.c @@ -185,6 +185,15 @@ struct bigben_device { struct work_struct worker; }; +static inline void bigben_schedule_work(struct bigben_device *bigben) +{ + unsigned long flags; + + spin_lock_irqsave(&bigben->lock, flags); + if (!bigben->removed) + schedule_work(&bigben->worker); + spin_unlock_irqrestore(&bigben->lock, flags); +} static void bigben_worker(struct work_struct *work) { @@ -197,9 +206,6 @@ static void bigben_worker(struct work_struct *work) u32 len; unsigned long flags; - if (bigben->removed) - return; - buf = hid_alloc_report_buf(bigben->report, GFP_KERNEL); if (!buf) return; @@ -285,7 +291,7 @@ static int hid_bigben_play_effect(struct input_dev *dev, void *data, bigben->work_ff = true; spin_unlock_irqrestore(&bigben->lock, flags); - schedule_work(&bigben->worker); + bigben_schedule_work(bigben); } return 0; @@ -320,7 +326,7 @@ static void bigben_set_led(struct led_classdev *led, if (work) { bigben->work_led = true; - schedule_work(&bigben->worker); + bigben_schedule_work(bigben); } return; } @@ -450,7 +456,7 @@ static int bigben_probe(struct hid_device *hid, bigben->left_motor_force = 0; bigben->work_led = true; bigben->work_ff = true; - schedule_work(&bigben->worker); + bigben_schedule_work(bigben); hid_info(hid, "LED and force feedback support for BigBen gamepad\n");