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 3229A27979A; Wed, 8 Apr 2026 18:38:31 +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=1775673511; cv=none; b=goxbEdhKqaJUCGTI21Ua0jYPykoUiCn+GpS6WGb2jR9ChPWER9tOC7PWXm/lj5zAIAiNwXj7ZMKvWd/Bq0cCJpZI+NL7aCD+gNtvrEjzkfhISsw67gXfBlknsUepbF1oNxWW9ExaWEuLQSGC+WklxmrPrdE5snU4SOAeudnjug4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775673511; c=relaxed/simple; bh=j5KQhBD1cJxZIYbKXF9CUqqSAQGp2gE7yK3CzFjVzZQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Rkjnp8KVbbPMG22yOJOKv7k2vuh2yDXZ9nATAOFbbnumxclaR/2kt950b29Vq9W7m3IjKgStIKoN4sXfotHpf3/2+1Tm+YN5FrSxzBjFITH3kCDhzm20O4SpZB1oq41qHLi741K0qWpq+66ZUNpss+pnh44gOoHmmFfGkA6LaIE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=nW+GCG6Q; 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="nW+GCG6Q" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BBB79C19421; Wed, 8 Apr 2026 18:38:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1775673511; bh=j5KQhBD1cJxZIYbKXF9CUqqSAQGp2gE7yK3CzFjVzZQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nW+GCG6QAvetm0wodz9B8KMkDf5J20ZfnaAwgnkNGu7ogUboPPIowOSqJieaAWZWl gvYUUsXlgCOEDyuArG6i0QcTbWN8RY5OEiTcg4a2pNmE1stvF5FEzzEX73P7izvAC2 hO6Rsb8ExWxre4vNyItst5N3DhlDoo6DcHGcRu9c= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Michael Zimmermann , stable Subject: [PATCH 6.18 261/277] usb: gadget: f_hid: move list and spinlock inits from bind to alloc Date: Wed, 8 Apr 2026 20:04:06 +0200 Message-ID: <20260408175943.602016646@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260408175933.836769063@linuxfoundation.org> References: <20260408175933.836769063@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: Michael Zimmermann commit 4e0a88254ad59f6c53a34bf5fa241884ec09e8b2 upstream. There was an issue when you did the following: - setup and bind an hid gadget - open /dev/hidg0 - use the resulting fd in EPOLL_CTL_ADD - unbind the UDC - bind the UDC - use the fd in EPOLL_CTL_DEL When CONFIG_DEBUG_LIST was enabled, a list_del corruption was reported within remove_wait_queue (via ep_remove_wait_queue). After some debugging I found out that the queues, which f_hid registers via poll_wait were the problem. These were initialized using init_waitqueue_head inside hidg_bind. So effectively, the bind function re-initialized the queues while there were still items in them. The solution is to move the initialization from hidg_bind to hidg_alloc to extend their lifetimes to the lifetime of the function instance. Additionally, I found many other possibly problematic init calls in the bind function, which I moved as well. Signed-off-by: Michael Zimmermann Cc: stable Link: https://patch.msgid.link/20260331184844.2388761-1-sigmaepsilon92@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/function/f_hid.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) --- a/drivers/usb/gadget/function/f_hid.c +++ b/drivers/usb/gadget/function/f_hid.c @@ -1262,17 +1262,8 @@ static int hidg_bind(struct usb_configur if (status) goto fail; - spin_lock_init(&hidg->write_spinlock); hidg->write_pending = 1; hidg->req = NULL; - spin_lock_init(&hidg->read_spinlock); - spin_lock_init(&hidg->get_report_spinlock); - init_waitqueue_head(&hidg->write_queue); - init_waitqueue_head(&hidg->read_queue); - init_waitqueue_head(&hidg->get_queue); - init_waitqueue_head(&hidg->get_id_queue); - INIT_LIST_HEAD(&hidg->completed_out_req); - INIT_LIST_HEAD(&hidg->report_list); INIT_WORK(&hidg->work, get_report_workqueue_handler); hidg->workqueue = alloc_workqueue("report_work", @@ -1609,6 +1600,16 @@ static struct usb_function *hidg_alloc(s mutex_lock(&opts->lock); + spin_lock_init(&hidg->write_spinlock); + spin_lock_init(&hidg->read_spinlock); + spin_lock_init(&hidg->get_report_spinlock); + init_waitqueue_head(&hidg->write_queue); + init_waitqueue_head(&hidg->read_queue); + init_waitqueue_head(&hidg->get_queue); + init_waitqueue_head(&hidg->get_id_queue); + INIT_LIST_HEAD(&hidg->completed_out_req); + INIT_LIST_HEAD(&hidg->report_list); + device_initialize(&hidg->dev); hidg->dev.release = hidg_release; hidg->dev.class = &hidg_class;