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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 C7322C43219 for ; Sat, 27 Apr 2019 15:26:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A491E208C2 for ; Sat, 27 Apr 2019 15:26:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728480AbfD0P0O (ORCPT ); Sat, 27 Apr 2019 11:26:14 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:34868 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727753AbfD0P0M (ORCPT ); Sat, 27 Apr 2019 11:26:12 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hKP3A-0000zM-Jf; Sat, 27 Apr 2019 16:15:36 +0100 Received: from ben by deadeye with local (Exim 4.92) (envelope-from ) id 1hKP2i-0004Ru-LD; Sat, 27 Apr 2019 16:15:08 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "syzbot" , "Greg Kroah-Hartman" , "Paul Fulghum" , "Arnd Bergmann" , "Tetsuo Handa" , "Alan Cox" Date: Sat, 27 Apr 2019 16:13:09 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 054/202] tty/n_hdlc: fix __might_sleep warning In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.66-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Paul Fulghum commit fc01d8c61ce02c034e67378cd3e645734bc18c8c upstream. Fix __might_sleep warning[1] in tty/n_hdlc.c read due to copy_to_user call while current is TASK_INTERRUPTIBLE. This is a false positive since the code path does not depend on current state remaining TASK_INTERRUPTIBLE. The loop breaks out and sets TASK_RUNNING after calling copy_to_user. This patch supresses the warning by setting TASK_RUNNING before calling copy_to_user. [1] https://syzkaller.appspot.com/bug?id=17d5de7f1fcab794cb8c40032f893f52de899324 Signed-off-by: Paul Fulghum Reported-by: syzbot Cc: Tetsuo Handa Cc: Alan Cox Acked-by: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings --- drivers/tty/n_hdlc.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/tty/n_hdlc.c +++ b/drivers/tty/n_hdlc.c @@ -598,6 +598,7 @@ static ssize_t n_hdlc_tty_read(struct tt /* too large for caller's buffer */ ret = -EOVERFLOW; } else { + __set_current_state(TASK_RUNNING); if (copy_to_user(buf, rbuf->buf, rbuf->count)) ret = -EFAULT; else