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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE83AC4167B for ; Sun, 26 Nov 2023 05:35:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229608AbjKZFfi (ORCPT ); Sun, 26 Nov 2023 00:35:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51504 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229456AbjKZFfg (ORCPT ); Sun, 26 Nov 2023 00:35:36 -0500 Received: from mail-pj1-f71.google.com (mail-pj1-f71.google.com [209.85.216.71]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A4FC0CE for ; Sat, 25 Nov 2023 21:35:42 -0800 (PST) Received: by mail-pj1-f71.google.com with SMTP id 98e67ed59e1d1-2859447a409so2917496a91.2 for ; Sat, 25 Nov 2023 21:35:42 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1700976942; x=1701581742; h=to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=IMzzzrHQcZNtfEipT/FghEZuPLoklrOQYabnOYQ35gw=; b=gz41cLPyvWdbXcxnHqI9F+JF0hgiA4U2VUdjNU4eawpZULySrJy1vEFaRPvJ5auRr8 b4iGkhB5uiRGKPsm04gK9+WAW4aFmjiEW3jCyIOy6onmvJXR3PZGcioPY/p2P/AuyehC T1LxfrshH6z5oPOp+M0gUJ47qMnL8urPZH0cjTwE8jDegRp9xdGXZctAgaDDI0aIXFlz Msn39XqVdj9p+IyJQQtUvogGa14lLk5QB1NQeXKINYTRaEwmSNF/pBRcYCxTnkDv3+b0 32JujwUmMWpn62KpXXwEPIqiymMGmy+pz3dKROk9t/Zlpjvk0tgQ36kRbeKzZDD5Yr7G 28jQ== X-Gm-Message-State: AOJu0YzJjegGesrnQH0q4gGiCYGJbDaIvjEoqAshVeF7eFcDk6m547Fv GfcFF1AQFi32HAPgsirGI2qKW9E14Rotb1W3whGk1LSuwWVNYbU= X-Google-Smtp-Source: AGHT+IHSztTlrTEa/jevK+l0xzTK7J8H1WwggyCThRolPNgvXGbwMVWfDwI7nv6qgHT7d8jeqNGuDnLMAvauhNoWiD9qV+q9mzOw MIME-Version: 1.0 X-Received: by 2002:a17:90a:69c4:b0:281:1c2e:9e6c with SMTP id s62-20020a17090a69c400b002811c2e9e6cmr1512585pjj.5.1700976942266; Sat, 25 Nov 2023 21:35:42 -0800 (PST) Date: Sat, 25 Nov 2023 21:35:42 -0800 In-Reply-To: <0000000000003d77e6060af9f233@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000006a40ed060b078eb9@google.com> Subject: Re: [syzbot] [crypto?] INFO: task hung in hwrng_fillfn From: syzbot To: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org For archival purposes, forwarding an incoming command email to linux-kernel@vger.kernel.org. *** Subject: [crypto?] INFO: task hung in hwrng_fillfn Author: eadavis@qq.com please test task hung in hwrng_fillfn #syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 98b1cc82c4af diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index 420f155d251f..883412bbf9f2 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -225,17 +225,18 @@ static ssize_t rng_dev_read(struct file *filp, char __user *buf, goto out; } - if (mutex_lock_interruptible(&reading_mutex)) { - err = -ERESTARTSYS; - goto out_put; - } if (!data_avail) { + if (mutex_lock_interruptible(&reading_mutex)) { + err = -ERESTARTSYS; + goto out_put; + } bytes_read = rng_get_data(rng, rng_buffer, rng_buffer_size(), !(filp->f_flags & O_NONBLOCK)); + mutex_unlock(&reading_mutex); if (bytes_read < 0) { err = bytes_read; - goto out_unlock_reading; + goto out_put; } data_avail = bytes_read; } @@ -243,7 +244,7 @@ static ssize_t rng_dev_read(struct file *filp, char __user *buf, if (!data_avail) { if (filp->f_flags & O_NONBLOCK) { err = -EAGAIN; - goto out_unlock_reading; + goto out_put; } } else { len = data_avail; @@ -255,14 +256,13 @@ static ssize_t rng_dev_read(struct file *filp, char __user *buf, if (copy_to_user(buf + ret, rng_buffer + data_avail, len)) { err = -EFAULT; - goto out_unlock_reading; + goto out_put; } size -= len; ret += len; } - mutex_unlock(&reading_mutex); put_rng(rng); if (need_resched()) @@ -276,8 +276,6 @@ static ssize_t rng_dev_read(struct file *filp, char __user *buf, out: return ret ? : err; -out_unlock_reading: - mutex_unlock(&reading_mutex); out_put: put_rng(rng); goto out; @@ -501,7 +499,10 @@ static int hwrng_fillfn(void *unused) rng = get_current_rng(); if (IS_ERR(rng) || !rng) break; - mutex_lock(&reading_mutex); + if (mutex_lock_interruptible(&reading_mutex)) { + put_rng(rng); + return -ERESTARTSYS; + } rc = rng_get_data(rng, rng_fillbuf, rng_buffer_size(), 1); if (current_quality != rng->quality)