From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 0985A223DC6; Sat, 30 May 2026 17:45:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780163157; cv=none; b=Bzimo9atd71hnoZhE4SstVRk3l+FWQlrxwHooE3Giuqida2LNrDuxNFjsdbVomowbF8k0e0VDpjgklRjHE2uikoTyHVZJS3OBEE09j1fvdT3K6L7dUvSluGRvNSxKzAqUtWOVj6JWk83lpApiLLOZAiE+obGBJVJJyVJw1xL/Es= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780163157; c=relaxed/simple; bh=iBx8hafQ2vwsyC6mx1yOM25Vqx4IfAUY+YzN05BMw3c=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=eolixvRcohZRJHDy0zZ5yn/qitqLrnZsxeDcrrng09pr0rM2SyIYX0LBTuq593/I4yLcXQ+L40FJxf7QzOCoUjBPF30XpCR5mfrUcZHoo7Owz/3H+FTNF25tcCk8r2XHqGpHrFkZuTnjkFgW9+4CiDxTCdILAB1FLVl3v2AWKEo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=VM4QD3+9; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="VM4QD3+9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 43EBC1F00893; Sat, 30 May 2026 17:45:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780163155; bh=JgMqU9WYo3yC/l8C6+JIpIyr5bfPry43Pm9h8vyG0i8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=VM4QD3+9TBAQkBSqM4/Ke3ViZXgxid9pOm6uY48ez5DUMSCtFZiTCMMK7lZqGwE1J sT+LOOUle1kbZscACzFXPVMx/Vj+FZsDhvSv563DKID2NSuSWW+EkGJQCU7xruhlbA Zy9zaNiB8APHG7maep6Sz+1aVrEOkEVvuZVTSab8= 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 5.15 174/776] ALSA: caiaq: take a reference on the USB device in create_card() Date: Sat, 30 May 2026 17:58:08 +0200 Message-ID: <20260530160244.995866822@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160240.228940103@linuxfoundation.org> References: <20260530160240.228940103@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-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));