From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1C0173563D4; Fri, 24 Apr 2026 13:42:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777038169; cv=none; b=a8f9Drp7pSpout+b5UlHFlb94cAaWfUE05a2uTZ8c3NJFpUULmBEUMYhl2+mocH/edWWsSdYEyi6mR+ZCqloSpx8V2WZFduVJOy96rrXZZFqTW7BMCNUfimPwmQ6gIPtSE+Hu8G40/QsKCRaGMuqmvNcRlWwnaaVzOP9CWaxRog= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777038169; c=relaxed/simple; bh=P2AbJMnmxtObuab1Tu7S/hRGql2xgPKSLiMLvvdOTog=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bkFO1gAGgPJs52oFtwXTNnJH0yKsHoXEqrRaXSS7D8rKFD/RIqC3Ucoe7Zb+pK5De5/5/0hqimBFnVC8v6HGzKF4Y8OoXEbIfRK1TOHrQ+2V9tbLFilkAGj8touMEYzq0BOxa7bOeGkvgdVikrsIfsZDELJfX5MaM8W/eSFeOwI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ffHc7gBL; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ffHc7gBL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A8291C19425; Fri, 24 Apr 2026 13:42:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1777038169; bh=P2AbJMnmxtObuab1Tu7S/hRGql2xgPKSLiMLvvdOTog=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ffHc7gBLPqLc2hrJe1Jpvg5HJzwMQV+vBRk7URi7g2uJn4a6jroK0Of39Q3JEYDkU w6Gs8K0MXR/7Ciw36kKApuNxkRI1REdoSXtVVS2rotFfm4R2B3RUfTGeUdZ2pxWMJm dd4BopKgPCOOywHqYqONMJ5s6CBGyZZHKR44qkUU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Andrey Konovalov , Berk Cem Goksel , Takashi Iwai Subject: [PATCH 6.18 50/55] ALSA: caiaq: take a reference on the USB device in create_card() Date: Fri, 24 Apr 2026 15:31:29 +0200 Message-ID: <20260424132440.510146454@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260424132430.006424517@linuxfoundation.org> References: <20260424132430.006424517@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Berk Cem Goksel commit 80bb50e2d459213cccff3111d5ef98ed4238c0d5 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- sound/usb/caiaq/device.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/sound/usb/caiaq/device.c +++ b/sound/usb/caiaq/device.c @@ -384,7 +384,7 @@ static void card_free(struct snd_card *c 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 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));