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=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,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 89CF6C43387 for ; Tue, 1 Jan 2019 20:28:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4898C2171F for ; Tue, 1 Jan 2019 20:28:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=microgate-com.20150623.gappssmtp.com header.i=@microgate-com.20150623.gappssmtp.com header.b="dih6BhoA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726822AbfAAU24 (ORCPT ); Tue, 1 Jan 2019 15:28:56 -0500 Received: from mail-pl1-f195.google.com ([209.85.214.195]:44220 "EHLO mail-pl1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726747AbfAAU2z (ORCPT ); Tue, 1 Jan 2019 15:28:55 -0500 Received: by mail-pl1-f195.google.com with SMTP id e11so13705238plt.11 for ; Tue, 01 Jan 2019 12:28:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=microgate-com.20150623.gappssmtp.com; s=20150623; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=VMXygqeRMN1W83XBoaIlpxbglZRQRMOh3rD875r6cPc=; b=dih6BhoAxbu2i4lGmB8B/RjzmpSjs1nIOpYVxgIZRJoT3fnpeEq/QZdthHkRXvWj0t 1GWqd0k5VblW1iLp8KoiuilsPPpGdZ79y6IbsBf6FnoVTovmHR+0i1JhX/P4ldV5/EaN 9RbRiyiI2OfiNBDBZ8SnJyWewl11bkQV7LgeTKAhY/PzcYeqN2TEU55HLkbglMbun4nq 9ZzI02CGlJz7iSLcRb+HJ86KSTu9Lv3E3O9ci68ShRinr+7onauAoVL3XBDskkTLZjcW GHygWXV7IEb/l7hWOvr6rFpgG7Z7+F//s317NIfwUdxXGlO7G+ReGBwuQyggNPvewSK1 281g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=VMXygqeRMN1W83XBoaIlpxbglZRQRMOh3rD875r6cPc=; b=HSGn/EPGugJNtNpmF7AvbrRZ77AtyKhxGg5Nd4p03pelLYP+MPmukRbTtXjW1EaEXf pzeueWGwfjhvHqpEaKvLagCWz1jAeuGMgY/vvLac+GMHlgIlo9noukI0O4ddEl4VZ7EA poMABbC9ekuxopCYvGjxXZMeBTbKAOYI7Ad9ySRjadvxC1F9d1OmtDIR7A1WqXQscqhE yeA+bivpKkYBJp4etSWdGoJS1ec/9VqVlZ895dHlyqN831GjkjBUqLFN1cOMatIwxYRG BI1+gds9LwPyJMovTzOVEUGya2wznmTYk6S3cJ67kelXNJ0Td34JSYW0caqVNfwMRIfK jo9Q== X-Gm-Message-State: AJcUukfbkDPhl8cxL2Sr5l0ecERZCX65p61vH07i/z9vnsd2i+OUPBgK z4GNYXGyVyy7A9hnDelpEuCUSQKotG0= X-Google-Smtp-Source: ALg8bN7WUZClRGzOOlUZz9RiGL4pLDK3+xWx2iHuIX8mnc32H/vaqcVLAYxSxpiJ0JpxdbUtu/X8yA== X-Received: by 2002:a17:902:9305:: with SMTP id bc5mr40950710plb.86.1546374534850; Tue, 01 Jan 2019 12:28:54 -0800 (PST) Received: from [192.168.1.77] (c.208.53.119.160.static.broadstripe.net. [208.53.119.160]) by smtp.gmail.com with ESMTPSA id t5sm76141876pfb.60.2019.01.01.12.28.53 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 01 Jan 2019 12:28:54 -0800 (PST) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 12.2 \(3445.102.3\)) Subject: [PATCH] tty/n_hdlc: fix __might_sleep warning From: Paul Fulghum In-Reply-To: <62FAC6A3-AC41-44CD-8ABC-79F404BF8CB1@microgate.com> Date: Tue, 1 Jan 2019 12:28:53 -0800 Cc: Greg Kroah-Hartman , Tetsuo Handa , Arnd Bergmann , Alan Cox , syzbot , jslaby@suse.com, syzkaller-bugs@googlegroups.com Content-Transfer-Encoding: quoted-printable Message-Id: References: <000000000000449587057e1e6f8b@google.com> <49b3b189-a51f-6a97-0e1f-bc3f2c305299@I-love.SAKURA.ne.jp> <62FAC6A3-AC41-44CD-8ABC-79F404BF8CB1@microgate.com> To: "linux-kernel@vger.kernel.org Mailing List" X-Mailer: Apple Mail (2.3445.102.3) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Fix __might_sleep warning 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.=20 This patch supresses the warning by setting TASK_RUNNING before calling = copy_to_user. [1] = https://syzkaller.appspot.com/bug?id=3D17d5de7f1fcab794cb8c40032f893f52de8= 99324 Signed-off-by: Paul Fulghum Reported-by: syzbot = Cc: Greg Kroah-Hartman Cc: Tetsuo Handa Cc: Arnd Bergmann Cc: Alan Cox =E2=80=94 --- a/drivers/tty/n_hdlc.c 2018-12-23 15:55:59.000000000 -0800 +++ b/drivers/tty/n_hdlc.c 2019-01-01 11:44:47.148153954 -0800 @@ -597,6 +597,7 @@ static ssize_t n_hdlc_tty_read(struct tt /* too large for caller's buffer */ ret =3D -EOVERFLOW; } else { + __set_current_state(TASK_RUNNING); if (copy_to_user(buf, rbuf->buf, = rbuf->count)) ret =3D -EFAULT; else =20=