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 3AD26C4167B for ; Sun, 26 Nov 2023 04:06:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230270AbjKZEGi (ORCPT ); Sat, 25 Nov 2023 23:06:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35214 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229507AbjKZEGe (ORCPT ); Sat, 25 Nov 2023 23:06:34 -0500 Received: from mail-pl1-f199.google.com (mail-pl1-f199.google.com [209.85.214.199]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0098A119 for ; Sat, 25 Nov 2023 20:06:40 -0800 (PST) Received: by mail-pl1-f199.google.com with SMTP id d9443c01a7336-1cc41aed6a5so35005775ad.0 for ; Sat, 25 Nov 2023 20:06:40 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1700971600; x=1701576400; 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=rCTrEUjlpw0O3E6ExzGBoitE7zCxScKjyxwFQWfN4MpkeViqzCG/m4BG/saONyDzHP /CE03YpbBgiLmOsUud64zdxdm+Jn+Nsrco/fxqA0rhkXw8Qiq+1YVrAvEIpEYfQSebW2 5rlDo/CVvlFtEKVicdOEjHqbsCyW2jYjVsfDu0U57rTrkgoTj+q74NvN6W3YCF4HPonM IDSwdO7HCQq6gzhmarCMGLdhI87Ssepj/tIQWdtG7LE16tJg7zrC0ZqxF3+PZsx+iV8Z toTbPBoYkOLd3PA+c6t1xCluABHzHUFLEYYKIIVbKaMr7Wv/LwjAzN4xtZbmbo6bitwH 5v6w== X-Gm-Message-State: AOJu0Yy9MNzlLOuCn9rghpPG45ZuK8pojBMLR5h4tl7VBLmaqi2y+wNS Yl8Tc+R4AVXFzv5JfVeZmdz4IBDXjYGCChnJvYaGRtB/FvSYluE= X-Google-Smtp-Source: AGHT+IG2IHumVHisiAK6hCFvXONYk5doA4dXNVPUvWveZstJkVj2FF4PY4GQpkwFL/d8sZvhes0zQKROmkhqA2Mjix2v8c7vx17s MIME-Version: 1.0 X-Received: by 2002:a17:902:db10:b0:1cf:c19e:5be7 with SMTP id m16-20020a170902db1000b001cfc19e5be7mr429772plx.12.1700971600482; Sat, 25 Nov 2023 20:06:40 -0800 (PST) Date: Sat, 25 Nov 2023 20:06:40 -0800 In-Reply-To: <0000000000003d77e6060af9f233@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000051b7b060b0650d4@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)