From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:53832 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727565AbeIXSGT (ORCPT ); Mon, 24 Sep 2018 14:06:19 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jia-Ju Bai Subject: [PATCH 4.9 064/111] usb: misc: uss720: Fix two sleep-in-atomic-context bugs Date: Mon, 24 Sep 2018 13:52:31 +0200 Message-Id: <20180924113111.265083900@linuxfoundation.org> In-Reply-To: <20180924113103.337261320@linuxfoundation.org> References: <20180924113103.337261320@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jia-Ju Bai commit bc8acc214d3f1cafebcbcd101a695bbac716595d upstream. async_complete() in uss720.c is a completion handler function for the USB driver. So it should not sleep, but it is can sleep according to the function call paths (from bottom to top) in Linux-4.16. [FUNC] set_1284_register(GFP_KERNEL) drivers/usb/misc/uss720.c, 372: set_1284_register in parport_uss720_frob_control drivers/parport/ieee1284.c, 560: [FUNC_PTR]parport_uss720_frob_control in parport_ieee1284_ack_data_avail drivers/parport/ieee1284.c, 577: parport_ieee1284_ack_data_avail in parport_ieee1284_interrupt ./include/linux/parport.h, 474: parport_ieee1284_interrupt in parport_generic_irq drivers/usb/misc/uss720.c, 116: parport_generic_irq in async_complete [FUNC] get_1284_register(GFP_KERNEL) drivers/usb/misc/uss720.c, 382: get_1284_register in parport_uss720_read_status drivers/parport/ieee1284.c, 555: [FUNC_PTR]parport_uss720_read_status in parport_ieee1284_ack_data_avail drivers/parport/ieee1284.c, 577: parport_ieee1284_ack_data_avail in parport_ieee1284_interrupt ./include/linux/parport.h, 474: parport_ieee1284_interrupt in parport_generic_irq drivers/usb/misc/uss720.c, 116: parport_generic_irq in async_complete Note that [FUNC_PTR] means a function pointer call is used. To fix these bugs, GFP_KERNEL is replaced with GFP_ATOMIC. These bugs are found by my static analysis tool DSAC. Signed-off-by: Jia-Ju Bai Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/misc/uss720.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/usb/misc/uss720.c +++ b/drivers/usb/misc/uss720.c @@ -385,7 +385,7 @@ static unsigned char parport_uss720_frob mask &= 0x0f; val &= 0x0f; d = (priv->reg[1] & (~mask)) ^ val; - if (set_1284_register(pp, 2, d, GFP_KERNEL)) + if (set_1284_register(pp, 2, d, GFP_ATOMIC)) return 0; priv->reg[1] = d; return d & 0xf; @@ -395,7 +395,7 @@ static unsigned char parport_uss720_read { unsigned char ret; - if (get_1284_register(pp, 1, &ret, GFP_KERNEL)) + if (get_1284_register(pp, 1, &ret, GFP_ATOMIC)) return 0; return ret & 0xf8; }