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=-14.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 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 AA227C433B4 for ; Mon, 17 May 2021 13:40:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 846B1610E9 for ; Mon, 17 May 2021 13:40:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237432AbhEQNl5 (ORCPT ); Mon, 17 May 2021 09:41:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58112 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237414AbhEQNl4 (ORCPT ); Mon, 17 May 2021 09:41:56 -0400 Received: from mail-lf1-x136.google.com (mail-lf1-x136.google.com [IPv6:2a00:1450:4864:20::136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 05B61C061573; Mon, 17 May 2021 06:40:39 -0700 (PDT) Received: by mail-lf1-x136.google.com with SMTP id j10so8828344lfb.12; Mon, 17 May 2021 06:40:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=uwmsFmAlOo76er6Ji5UTRtBzo940BiJI4cuJFCDeXfU=; b=UbVcU25g+r45EQTwnm5XC1IOOnRNwgWrtDyxScOR/YTVoFKqzGlP4B1BOwrph9s3j0 wCamxC//WsFQ6rS/eOHdKdkoehjoCvPCGuhzp7YR311zH5Jpe+QUZhmHsZ+sI0eyKz3E 39Gc+YlVZCGtGnfkUbwP4EzVSjxny52IRi/pjVXPLsAdcl5R1zD2aIZfOYHRllPGVG1x 8sCO9BTybuIFShckdHjyLXzCGDs/jfsm7zMUGeEBhAZghwrbI4dWlNmbc/4XbM2zz5qC 8Cqd6Bde0S1c3aP9Jn01B1i4bfoUPM/jTrBo95gmh9E2hOuQwllvwrZ/H5L8POG1PAo4 zp8A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=uwmsFmAlOo76er6Ji5UTRtBzo940BiJI4cuJFCDeXfU=; b=oJlIqDGmSQokT+9C63HVy4LW/Hvrj1I3B3cbj7EkNfkLcqoziOwva180kqzujUn1uh 4Bhmsc0f+EbLr08L5f50+nVXa+DS7fcCJsFhtQ2FVGf/FT8fBPpyJpZI08WwzRaM7eKH HTb6AHry63atpce8jGaotLKKovcXwqCyfhTEZ0dCgb2wL3W5LWnphm8JlPwTvDBJMb4P VPJaYuLGCMnU733HrqQTEbSlGF56QEZd6WIjhsE40ZHIO3B48Yf0K0vzk6aaFn0Wb4WT /4GWbQw8wo39318dtC169foSlBFlmv3OVamKuQIMznK+WO4B1nPcdC3GjmUgfJbMusaQ pfqQ== X-Gm-Message-State: AOAM530rrPcZI90hYhiPEDh5XjE7+u7R1V1GmgtQ9CVxfCJRpr0QgRly SItu5laLoLt5C9Cf7OBtkA8= X-Google-Smtp-Source: ABdhPJzTPGDuXem4nPuheC3gCCJ7o7R2hUL5WcXmbbZB/BMgNw7/iq3HGgGkVdvgElCr2q/6mB1vGg== X-Received: by 2002:a19:7012:: with SMTP id h18mr2838021lfc.432.1621258837508; Mon, 17 May 2021 06:40:37 -0700 (PDT) Received: from localhost.localdomain ([94.103.227.227]) by smtp.gmail.com with ESMTPSA id r1sm2899113ljj.21.2021.05.17.06.40.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 17 May 2021 06:40:37 -0700 (PDT) Date: Mon, 17 May 2021 16:40:34 +0300 From: Pavel Skripkin To: tytso@mit.edu, adilger.kernel@dilger.ca Cc: linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, syzbot+d9e482e303930fa4f6ff@syzkaller.appspotmail.com Subject: Re: [PATCH v2] ext4: fix memory leak in ext4_fill_super Message-ID: <20210517164034.1e7d712b@gmail.com> In-Reply-To: <20210430185046.15742-1-paskripkin@gmail.com> References: <20210430185046.15742-1-paskripkin@gmail.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-suse-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Hi! Is all ok with this one, or I should send v3? :) With regards, Pavel Skripkin On Fri, 30 Apr 2021 21:50:46 +0300 Pavel Skripkin wrote: > static int kthread(void *_create) will return -ENOMEM > or -EINTR in case of internal failure or > kthread_stop() call happens before threadfn call. > > To prevent fancy error checking and make code > more straightforward we moved all cleanup code out > of kmmpd threadfn. > > Also, dropped struct mmpd_data at all. Now struct super_block > is a threadfn data and struct buffer_head embedded into > struct ext4_sb_info. > > Reported-by: syzbot+d9e482e303930fa4f6ff@syzkaller.appspotmail.com > Signed-off-by: Pavel Skripkin > --- > fs/ext4/ext4.h | 4 ++++ > fs/ext4/mmp.c | 28 +++++++++++++--------------- > fs/ext4/super.c | 10 ++++------ > 3 files changed, 21 insertions(+), 21 deletions(-) > > diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h > index 826a56e3bbd2..62210cbea84b 100644 > --- a/fs/ext4/ext4.h > +++ b/fs/ext4/ext4.h > @@ -1490,6 +1490,7 @@ struct ext4_sb_info { > struct kobject s_kobj; > struct completion s_kobj_unregister; > struct super_block *s_sb; > + struct buffer_head *s_mmp_bh; > > /* Journaling */ > struct journal_s *s_journal; > @@ -3663,6 +3664,9 @@ extern struct ext4_io_end_vec > *ext4_last_io_end_vec(ext4_io_end_t *io_end); /* mmp.c */ > extern int ext4_multi_mount_protect(struct super_block *, > ext4_fsblk_t); > +/* mmp.c */ > +extern void ext4_stop_mmpd(struct ext4_sb_info *sbi); > + > /* verity.c */ > extern const struct fsverity_operations ext4_verityops; > > diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c > index 795c3ff2907c..623bad399612 100644 > --- a/fs/ext4/mmp.c > +++ b/fs/ext4/mmp.c > @@ -127,9 +127,9 @@ void __dump_mmp_msg(struct super_block *sb, > struct mmp_struct *mmp, */ > static int kmmpd(void *data) > { > - struct super_block *sb = ((struct mmpd_data *) data)->sb; > - struct buffer_head *bh = ((struct mmpd_data *) data)->bh; > + struct super_block *sb = (struct super_block *) data; > struct ext4_super_block *es = EXT4_SB(sb)->s_es; > + struct buffer_head *bh = EXT4_SB(sb)->s_mmp_bh; > struct mmp_struct *mmp; > ext4_fsblk_t mmp_block; > u32 seq = 0; > @@ -245,12 +245,18 @@ static int kmmpd(void *data) > retval = write_mmp_block(sb, bh); > > exit_thread: > - EXT4_SB(sb)->s_mmp_tsk = NULL; > - kfree(data); > - brelse(bh); > return retval; > } > > +void ext4_stop_mmpd(struct ext4_sb_info *sbi) > +{ > + if (sbi->s_mmp_tsk) { > + kthread_stop(sbi->s_mmp_tsk); > + brelse(sbi->s_mmp_bh); > + sbi->s_mmp_tsk = NULL; > + } > +} > + > /* > * Get a random new sequence number but make sure it is not greater > than > * EXT4_MMP_SEQ_MAX. > @@ -275,7 +281,6 @@ int ext4_multi_mount_protect(struct super_block > *sb, struct ext4_super_block *es = EXT4_SB(sb)->s_es; > struct buffer_head *bh = NULL; > struct mmp_struct *mmp = NULL; > - struct mmpd_data *mmpd_data; > u32 seq; > unsigned int mmp_check_interval = > le16_to_cpu(es->s_mmp_update_interval); unsigned int wait_time = 0; > @@ -364,24 +369,17 @@ int ext4_multi_mount_protect(struct super_block > *sb, goto failed; > } > > - mmpd_data = kmalloc(sizeof(*mmpd_data), GFP_KERNEL); > - if (!mmpd_data) { > - ext4_warning(sb, "not enough memory for mmpd_data"); > - goto failed; > - } > - mmpd_data->sb = sb; > - mmpd_data->bh = bh; > + EXT4_SB(sb)->s_mmp_bh = bh; > > /* > * Start a kernel thread to update the MMP block > periodically. */ > - EXT4_SB(sb)->s_mmp_tsk = kthread_run(kmmpd, mmpd_data, > "kmmpd-%.*s", > + EXT4_SB(sb)->s_mmp_tsk = kthread_run(kmmpd, sb, "kmmpd-%.*s", > (int)sizeof(mmp->mmp_bdevname), > bdevname(bh->b_bdev, > mmp->mmp_bdevname)); > if (IS_ERR(EXT4_SB(sb)->s_mmp_tsk)) { > EXT4_SB(sb)->s_mmp_tsk = NULL; > - kfree(mmpd_data); > ext4_warning(sb, "Unable to create kmmpd thread for > %s.", sb->s_id); > goto failed; > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > index b9693680463a..539f89c5431f 100644 > --- a/fs/ext4/super.c > +++ b/fs/ext4/super.c > @@ -1244,8 +1244,8 @@ static void ext4_put_super(struct super_block > *sb) ext4_xattr_destroy_cache(sbi->s_ea_block_cache); > sbi->s_ea_block_cache = NULL; > > - if (sbi->s_mmp_tsk) > - kthread_stop(sbi->s_mmp_tsk); > + ext4_stop_mmpd(sbi); > + > brelse(sbi->s_sbh); > sb->s_fs_info = NULL; > /* > @@ -5156,8 +5156,7 @@ static int ext4_fill_super(struct super_block > *sb, void *data, int silent) failed_mount3: > flush_work(&sbi->s_error_work); > del_timer_sync(&sbi->s_err_report); > - if (sbi->s_mmp_tsk) > - kthread_stop(sbi->s_mmp_tsk); > + ext4_stop_mmpd(sbi); > failed_mount2: > rcu_read_lock(); > group_desc = rcu_dereference(sbi->s_group_desc); > @@ -5952,8 +5951,7 @@ static int ext4_remount(struct super_block *sb, > int *flags, char *data) */ > ext4_mark_recovery_complete(sb, es); > } > - if (sbi->s_mmp_tsk) > - kthread_stop(sbi->s_mmp_tsk); > + ext4_stop_mmpd(sbi); > } else { > /* Make sure we can mount this feature set > readwrite */ if (ext4_has_feature_readonly(sb) ||