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 680F845A282; Tue, 21 Jul 2026 21:04:40 +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=1784667883; cv=none; b=QHMKtziQEd/WfOjJT1qk6dg5hBSKoulotr3hNFqjiFcz555vnWIHCog9450zcxZ8rA8uwwfYzQnuAojEDDD5sBptKOX+evOhvfqIqKgLMaJldhazqvs7yBR5vqW9adYA981xUQGtTaZzWbHRf20AmA04FWibk7OgMPDbTTw7Ha0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784667883; c=relaxed/simple; bh=P4aNkNCrbzNc1CjftI4W6JbIbimm4SdPfMcOsxnEZJk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=hUpNvLqKy0Q0oeiuzlSzXoMye+3mljnPLsUz/SRZJcR+fo/K0ETEZz63odumyaETREC7uun2CL7IeYHip9CyJtF96LGtOu3LhISCM6jkCrKQOVevSbUj8SIYWXPTZoCSvJYSMHOjq4l2GalfgTwjMFgxc67i+CYNgSWl8kyAdNM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=dSO0qpOx; 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="dSO0qpOx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D19E51F00A3D; Tue, 21 Jul 2026 21:04:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784667880; bh=aoBXop9KCX+ana7WBsjycqSd2Zyd7bVdeUfGl+aGJgc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=dSO0qpOxKXGQU94iLZOR/Ofby+guMQgTUPdegyhrpP6bXHTpDuz68wYrUAEx6gKOt QvdLiTax3K4xX8Inn5jMnem5ospbUBPl7VfeknNT3IdQylmLC8NCMyCrI9Ozx7j+6d NzfjBnO/wwm0G3N2OkNZ0o/7FfMO1emanUpDXWJQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable , Tyler Baker , Loic Poulain , Dmitry Baryshkov , Srinivas Kandagatla , Peter Chen , =?UTF-8?q?Micha=C5=82=20Nazarewicz?= , Sasha Levin Subject: [PATCH 6.6 1227/1266] usb: gadget: f_fs: initialize reset_work at allocation time Date: Tue, 21 Jul 2026 17:27:44 +0200 Message-ID: <20260721152509.262044840@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152441.786066624@linuxfoundation.org> References: <20260721152441.786066624@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-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tyler Baker [ Upstream commit 3137b243c93982fe3460335e12f9247739766e10 ] ffs_fs_kill_sb() unconditionally calls cancel_work_sync() on ffs->reset_work when a functionfs instance is unmounted: ffs_data_reset(ffs); cancel_work_sync(&ffs->reset_work); However ffs->reset_work is only ever initialized via INIT_WORK() in ffs_func_set_alt() and ffs_func_disable(), and only on the FFS_DEACTIVATED path. That state is reached solely by ffs_data_closed() when the instance is mounted with the "no_disconnect" option, so for the common case (no "no_disconnect", or mounted and unmounted without ever being deactivated) reset_work is never initialized. ffs_data_new() allocates the ffs_data with kzalloc_obj() and does not initialize reset_work, and ffs_data_reset()/ffs_data_clear() do not touch it either, so reset_work.func is left NULL. cancel_work_sync() on such a work then trips the WARN_ON(!work->func) guard in __flush_work(): WARNING: kernel/workqueue.c:4301 at __flush_work+0x330/0x360, CPU#3: umount Call trace: __flush_work cancel_work_sync ffs_fs_kill_sb [usb_f_fs] deactivate_locked_super deactivate_super cleanup_mnt __cleanup_mnt task_work_run exit_to_user_mode_loop el0_svc On older kernels cancel_work_sync() on a zero-initialized work struct was a silent no-op, which hid the missing initialization. Initialize reset_work once in ffs_data_new() so it is always valid for the lifetime of the ffs_data, and drop the now-redundant INIT_WORK() calls from the two deactivation paths. Fixes: 18d6b32fca38 ("usb: gadget: f_fs: add "no_disconnect" mode") Cc: stable Signed-off-by: Tyler Baker Cc: Loic Poulain Cc: Dmitry Baryshkov Cc: Srinivas Kandagatla Tested-by: Loic Poulain Reviewed-by: Peter Chen Acked-by: Michał Nazarewicz Link: https://patch.msgid.link/20260609193635.2284430-1-tyler.baker@oss.qualcomm.com Signed-off-by: Greg Kroah-Hartman [ dropped the ffs_func_disable hunk since 6.6 predates the disable-body split and routes disable through ffs_func_set_alt, so removing the single lazy INIT_WORK there covers both paths ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/function/f_fs.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -255,6 +255,7 @@ static int ffs_acquire_dev(const char *d static void ffs_release_dev(struct ffs_dev *ffs_dev); static int ffs_ready(struct ffs_data *ffs); static void ffs_closed(struct ffs_data *ffs); +static void ffs_reset_work(struct work_struct *work); /* Misc helper functions ****************************************************/ @@ -1734,6 +1735,7 @@ static struct ffs_data *ffs_data_new(con init_waitqueue_head(&ffs->ev.waitq); init_waitqueue_head(&ffs->wait); init_completion(&ffs->ep0req_completion); + INIT_WORK(&ffs->reset_work, ffs_reset_work); /* XXX REVISIT need to update it in some places, or do we? */ ffs->ev.can_stall = 1; @@ -3261,7 +3263,6 @@ static int ffs_func_set_alt(struct usb_f if (ffs->state == FFS_DEACTIVATED) { ffs->state = FFS_CLOSING; - INIT_WORK(&ffs->reset_work, ffs_reset_work); schedule_work(&ffs->reset_work); return -ENODEV; }