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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,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 B24C3C47082 for ; Tue, 8 Jun 2021 12:23:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9A96661073 for ; Tue, 8 Jun 2021 12:23:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232202AbhFHMZq (ORCPT ); Tue, 8 Jun 2021 08:25:46 -0400 Received: from wforward4-smtp.messagingengine.com ([64.147.123.34]:51517 "EHLO wforward4-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232492AbhFHMZq (ORCPT ); Tue, 8 Jun 2021 08:25:46 -0400 Received: from compute2.internal (compute2.nyi.internal [10.202.2.42]) by mailforward.west.internal (Postfix) with ESMTP id 472FC1CE6; Tue, 8 Jun 2021 08:23:53 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute2.internal (MEProxy); Tue, 08 Jun 2021 08:23:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:message-id:mime-version:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm3; bh=Ttj6gm iCm8VG9wMm87solWYT1hr4kjcqUZ1TIXFATOs=; b=IE3siBwU207v5CAYdoxpMr lQMc58q7o6YN8JcxUOrijSY2oyHEgAGry6NrCI3gyfuvASzoEvxkYOwPOse3i9+s htVt9J2OqxqTFpA3LdetSsCO7V/eySHuJ2SDv84qgez47l8hSrMbEq147caqk2J1 i8dwGEwLHUAjWPFJBjoh0pVOtRhVWxUte9r2w624KwsnfILLU5D7UBC1fs5vaVDM VZAskH78BQr8tHlZx9GaDqDWiWQ12yF/p5WWFsrawviWUe2nMwYz4CvTKX9OrUEo lTpp7qZfFmd987adVy0arg5cFkaklewj4jPYmnspem+Wfb6q6eoscjoC9B/viQ7w == X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduledrfedtledgfeehucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucenucfjughrpefuvffhfffkgggtgfesthekredttd dtlfenucfhrhhomhepoehgrhgvghhkhheslhhinhhugihfohhunhgurghtihhonhdrohhr gheqnecuggftrfgrthhtvghrnhepleelledvgeefleeltdetgedugeffgffhudffudduke egfeelgeeigeekjefhleevnecuffhomhgrihhnpehkvghrnhgvlhdrohhrghenucevlhhu shhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpehgrhgvgheskhhroh grhhdrtghomh X-ME-Proxy: Received: by mail.messagingengine.com (Postfix) with ESMTPA; Tue, 8 Jun 2021 08:23:52 -0400 (EDT) Subject: FAILED: patch "[PATCH] ext4: fix memory leak in ext4_fill_super" failed to apply to 5.4-stable tree To: amakhalov@vmware.com, tytso@mit.edu Cc: From: Date: Tue, 08 Jun 2021 14:23:50 +0200 Message-ID: <162315503023234@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From afd09b617db3786b6ef3dc43e28fe728cfea84df Mon Sep 17 00:00:00 2001 From: Alexey Makhalov Date: Fri, 21 May 2021 07:55:33 +0000 Subject: [PATCH] ext4: fix memory leak in ext4_fill_super Buffer head references must be released before calling kill_bdev(); otherwise the buffer head (and its page referenced by b_data) will not be freed by kill_bdev, and subsequently that bh will be leaked. If blocksizes differ, sb_set_blocksize() will kill current buffers and page cache by using kill_bdev(). And then super block will be reread again but using correct blocksize this time. sb_set_blocksize() didn't fully free superblock page and buffer head, and being busy, they were not freed and instead leaked. This can easily be reproduced by calling an infinite loop of: systemctl start .mount, and systemctl stop .mount ... since systemd creates a cgroup for each slice which it mounts, and the bh leak get amplified by a dying memory cgroup that also never gets freed, and memory consumption is much more easily noticed. Fixes: ce40733ce93d ("ext4: Check for return value from sb_set_blocksize") Fixes: ac27a0ec112a ("ext4: initial copy of files from ext3") Link: https://lore.kernel.org/r/20210521075533.95732-1-amakhalov@vmware.com Signed-off-by: Alexey Makhalov Signed-off-by: Theodore Ts'o Cc: stable@kernel.org diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 886e0d518668..f66c7301b53a 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -4462,14 +4462,20 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) } if (sb->s_blocksize != blocksize) { + /* + * bh must be released before kill_bdev(), otherwise + * it won't be freed and its page also. kill_bdev() + * is called by sb_set_blocksize(). + */ + brelse(bh); /* Validate the filesystem blocksize */ if (!sb_set_blocksize(sb, blocksize)) { ext4_msg(sb, KERN_ERR, "bad block size %d", blocksize); + bh = NULL; goto failed_mount; } - brelse(bh); logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE; offset = do_div(logical_sb_block, blocksize); bh = ext4_sb_bread_unmovable(sb, logical_sb_block); @@ -5202,8 +5208,9 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) kfree(get_qf_name(sb, sbi, i)); #endif fscrypt_free_dummy_policy(&sbi->s_dummy_enc_policy); - ext4_blkdev_remove(sbi); + /* ext4_blkdev_remove() calls kill_bdev(), release bh before it. */ brelse(bh); + ext4_blkdev_remove(sbi); out_fail: sb->s_fs_info = NULL; kfree(sbi->s_blockgroup_lock);