From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 60D7FC3276C for ; Thu, 2 Jan 2020 22:36:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 35D2320863 for ; Thu, 2 Jan 2020 22:36:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578004612; bh=aWwajad3FFOd5MGX83mrg5evnt4kXJ3VwXi8MagwZ7E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=kSc8KJpthkFrEsZuNJChkAp/+MPWxHKfMqWcaylbl7UJjP1pbOKqTi4qK1XQ/s8DE z9PWaF+7RdGiRewxBLiV6/CYcNx7jaq7PoxjzAx4H5NCegXxjAqGCflCt+r9lut+Fk Wo0i3uCFEWegFhpXF/mhYuT9tn5YLaxCB+0FG2iE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731003AbgABWgv (ORCPT ); Thu, 2 Jan 2020 17:36:51 -0500 Received: from mail.kernel.org ([198.145.29.99]:48432 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730991AbgABWgr (ORCPT ); Thu, 2 Jan 2020 17:36:47 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 03FBE20863; Thu, 2 Jan 2020 22:36:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578004607; bh=aWwajad3FFOd5MGX83mrg5evnt4kXJ3VwXi8MagwZ7E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bY+9jX+4TQRyLrFHUHYOcTgn/wxGyO7HpgouOHjzI6fnjfcwCAYnXfnw/dKIEPW8J 4qfd2rX42zqCNIaJHvB03NI5D35avANdjVl4XZofgBBISTpTjQEEplIfO1WFiZ+Syf BHm6+y6OMfHvLHJYmpu8BYbZYgNWfDGT6W+Jx5k4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jia-Ju Bai , "David S. Miller" Subject: [PATCH 4.4 077/137] net: nfc: nci: fix a possible sleep-in-atomic-context bug in nci_uart_tty_receive() Date: Thu, 2 Jan 2020 23:07:30 +0100 Message-Id: <20200102220557.086899682@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200102220546.618583146@linuxfoundation.org> References: <20200102220546.618583146@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jia-Ju Bai [ Upstream commit b7ac893652cafadcf669f78452329727e4e255cc ] The kernel may sleep while holding a spinlock. The function call path (from bottom to top) in Linux 4.19 is: net/nfc/nci/uart.c, 349: nci_skb_alloc in nci_uart_default_recv_buf net/nfc/nci/uart.c, 255: (FUNC_PTR)nci_uart_default_recv_buf in nci_uart_tty_receive net/nfc/nci/uart.c, 254: spin_lock in nci_uart_tty_receive nci_skb_alloc(GFP_KERNEL) can sleep at runtime. (FUNC_PTR) means a function pointer is called. To fix this bug, GFP_KERNEL is replaced with GFP_ATOMIC for nci_skb_alloc(). This bug is found by a static analysis tool STCheck written by myself. Signed-off-by: Jia-Ju Bai Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/nfc/nci/uart.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/nfc/nci/uart.c +++ b/net/nfc/nci/uart.c @@ -355,7 +355,7 @@ static int nci_uart_default_recv_buf(str nu->rx_packet_len = -1; nu->rx_skb = nci_skb_alloc(nu->ndev, NCI_MAX_PACKET_SIZE, - GFP_KERNEL); + GFP_ATOMIC); if (!nu->rx_skb) return -ENOMEM; }