From: Berk Cem Goksel Date: Mon, 13 Apr 2026 03:49:41 +0000 (+0300) Subject: ALSA: caiaq: take a reference on the USB device in create_card() X-Git-Url: http://git.ipfire.org/index.cgi?a=commitdiff_plain;h=80bb50e2d459213cccff3111d5ef98ed4238c0d5;p=thirdparty%2Flinux.git ALSA: caiaq: take a reference on the USB device in create_card() The caiaq driver stores a pointer to the parent USB device in cdev->chip.dev but never takes a reference on it. The card's private_free callback, snd_usb_caiaq_card_free(), can run asynchronously via snd_card_free_when_closed() after the USB device has already been disconnected and freed, so any access to cdev->chip.dev in that path dereferences a freed usb_device. On top of the refcounting issue, the current card_free implementation calls usb_reset_device(cdev->chip.dev). A reset in a free callback is inappropriate: the device is going away, the call takes the device lock in a teardown context, and the reset races with the disconnect path that the callback is already cleaning up after. Take a reference on the USB device in create_card() with usb_get_dev(), drop it with usb_put_dev() in the free callback, and remove the usb_reset_device() call. Fixes: b04dcbb7f7b1 ("ALSA: caiaq: Use snd_card_free_when_closed() at disconnection") Cc: stable@vger.kernel.org Cc: Andrey Konovalov Signed-off-by: Berk Cem Goksel Link: https://patch.msgid.link/20260413034941.1131465-3-berkcgoksel@gmail.com Signed-off-by: Takashi Iwai --- diff --git a/sound/usb/caiaq/device.c b/sound/usb/caiaq/device.c index 3a71bab8a4774..51177ebfb8c62 100644 --- a/sound/usb/caiaq/device.c +++ b/sound/usb/caiaq/device.c @@ -384,7 +384,7 @@ static void card_free(struct snd_card *card) snd_usb_caiaq_input_free(cdev); #endif snd_usb_caiaq_audio_free(cdev); - usb_reset_device(cdev->chip.dev); + usb_put_dev(cdev->chip.dev); } static int create_card(struct usb_device *usb_dev, @@ -410,7 +410,7 @@ static int create_card(struct usb_device *usb_dev, return err; cdev = caiaqdev(card); - cdev->chip.dev = usb_dev; + cdev->chip.dev = usb_get_dev(usb_dev); cdev->chip.card = card; cdev->chip.usb_id = USB_ID(le16_to_cpu(usb_dev->descriptor.idVendor), le16_to_cpu(usb_dev->descriptor.idProduct));