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 25DA237B409 for ; Sun, 12 Apr 2026 12:00:03 +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=1775995204; cv=none; b=seG2ly44Nwo5RWV3Nevp5H0/r6TYZMkS8zNKK7GnhKDZmyocEyiaJN/VogHq8GJDTxVpQzj4i9maPElx/nocCPtulhDp8SV7+cx0kX2wT9RCorQ2k1exSQ5yxP9txr4NaHD6Uv5+UHyIDxuCXFSYrzd/ASGmuXxQy2F7l1M6Sbs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775995204; c=relaxed/simple; bh=N49dKV3PD2oEa//TiAOA4ONTh/tS5mfmxWTFO5KOO9M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PMOUXABK3A5IUXe89B7rbniaQF6ie+nxS07vaqQcmeH0PJ3r7h7b2N8qsGFw4Q/nm7izrBVI9woUckCLIX9Fx+qDvY49jHhrnai0k1gi/ILtKzoaw2Tkv7u9qMHWnOiuttd83C6aEjBdJEWhFM/EqB2utuIP/zyNEP83LGE72AM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EQx7+D/9; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="EQx7+D/9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 02A27C19424; Sun, 12 Apr 2026 12:00:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775995203; bh=N49dKV3PD2oEa//TiAOA4ONTh/tS5mfmxWTFO5KOO9M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EQx7+D/9EhIWhndpYwjiIrdSJKO20Wef9M4dvViuOuYy9NZqQ2hTVw0H6U0RQ3m/w SAEsX4RgNKDsHdPQR7rT4d7iik4nBRX6EjR7N+F3Xy8SqdcFzHRcXAAbG/AZx6gI69 YajPvz2BquR16QaKdIGgYAs5R0cN9Ntd2Bf7yEgAzosSkMdFXIBY2BVXIj4eVA3qix 5hqQSTnXZgmeINmr6ZcaSYbQaCp31h946Gnazel8rTM/L5ffYJ0dSlxJDj9XeFCsWv p8Ax10D/MU76OuqrJ3u58GNAgFexRsg1fx2trHcAk1glMC5BRyx2nOEvXIQDKXG2PP p+SSRkYr5VHSQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Michael Zimmermann , stable , Greg Kroah-Hartman , Sasha Levin Subject: [PATCH 5.15.y] usb: gadget: f_hid: move list and spinlock inits from bind to alloc Date: Sun, 12 Apr 2026 08:00:00 -0400 Message-ID: <20260412120000.2096246-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026040827-jitters-comic-f139@gregkh> References: <2026040827-jitters-comic-f139@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Michael Zimmermann [ Upstream commit 4e0a88254ad59f6c53a34bf5fa241884ec09e8b2 ] 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 Signed-off-by: Sasha Levin --- drivers/usb/gadget/function/f_hid.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c index 1293bc9157087..f8cc26af702c9 100644 --- a/drivers/usb/gadget/function/f_hid.c +++ b/drivers/usb/gadget/function/f_hid.c @@ -996,13 +996,8 @@ static int hidg_bind(struct usb_configuration *c, struct usb_function *f) if (status) goto fail; - spin_lock_init(&hidg->write_spinlock); hidg->write_pending = 1; hidg->req = NULL; - spin_lock_init(&hidg->read_spinlock); - init_waitqueue_head(&hidg->write_queue); - init_waitqueue_head(&hidg->read_queue); - INIT_LIST_HEAD(&hidg->completed_out_req); /* create char device */ cdev_init(&hidg->cdev, &f_hidg_fops); @@ -1272,6 +1267,12 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi) mutex_lock(&opts->lock); ++opts->refcnt; + spin_lock_init(&hidg->write_spinlock); + spin_lock_init(&hidg->read_spinlock); + init_waitqueue_head(&hidg->write_queue); + init_waitqueue_head(&hidg->read_queue); + INIT_LIST_HEAD(&hidg->completed_out_req); + device_initialize(&hidg->dev); hidg->dev.release = hidg_release; hidg->dev.class = hidg_class; -- 2.53.0