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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=no 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 02226C432C0 for ; Sun, 1 Dec 2019 01:56:37 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id BB8CE205ED for ; Sun, 1 Dec 2019 01:56:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="SeDGABc7" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BB8CE205ED Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 694CE6B0356; Sat, 30 Nov 2019 20:56:36 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 61FAD6B0358; Sat, 30 Nov 2019 20:56:36 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4973B6B0359; Sat, 30 Nov 2019 20:56:36 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0074.hostedemail.com [216.40.44.74]) by kanga.kvack.org (Postfix) with ESMTP id 307806B0356 for ; Sat, 30 Nov 2019 20:56:36 -0500 (EST) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id E663D181AEF0B for ; Sun, 1 Dec 2019 01:56:35 +0000 (UTC) X-FDA: 76214908350.27.ice69_39936ea11d63c X-HE-Tag: ice69_39936ea11d63c X-Filterd-Recvd-Size: 3761 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf06.hostedemail.com (Postfix) with ESMTP for ; Sun, 1 Dec 2019 01:56:35 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9CDE02245C; Sun, 1 Dec 2019 01:56:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575165395; bh=o/eH1qjEbTPSu3YScR5azrGpL5hdpewneNtOsaL5NzA=; h=Date:From:To:Subject:From; b=SeDGABc7NT6Umvskqvtr8F7b8RIRbA5LbK8CfvSjWn1UjWW98kdvOl1w+oy3xCIU9 D0qqyV0FDc/DPjn/xZo9eFS/7eyjp6ryzO9ugfCFzAmsAKxnUpqSONpkoPrhaDbbM1 8u/roByWt704JZB1YS7eoEdLqnSfrmOpl0sYLv/0= Date: Sat, 30 Nov 2019 17:56:34 -0800 From: akpm@linux-foundation.org To: akpm@linux-foundation.org, cgxu519@mykernel.net, dhowells@redhat.com, linux-mm@kvack.org, mike.kravetz@oracle.com, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, viro@zeniv.linux.org.uk Subject: [patch 124/158] mm/hugetlbfs: fix error handling when setting up mounts Message-ID: <20191201015634.09yQyxNwN%akpm@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Mike Kravetz Subject: mm/hugetlbfs: fix error handling when setting up mounts It is assumed that the hugetlbfs_vfsmount[] array will contain either a valid vfsmount pointer or NULL for each hstate after initialization. Changes made while converting to use fs_context broke this assumption. While fixing the hugetlbfs_vfsmount issue, it was discovered that init_hugetlbfs_fs never did correctly clean up when encountering a vfs mount error. It was found during code inspection. A small memory allocation failure would be the most likely cause of taking a error path with the bug. This is unlikely to happen as this is early init code. Link: http://lkml.kernel.org/r/94b6244d-2c24-e269-b12c-e3ba694b242d@oracle.com Reported-by: Chengguang Xu Fixes: 32021982a324 ("hugetlbfs: Convert to fs_context") Signed-off-by: Mike Kravetz Cc: David Howells Cc: Al Viro Signed-off-by: Andrew Morton --- fs/hugetlbfs/inode.c | 31 ++++++++++++++++++++++--------- 1 file changed, 22 insertions(+), 9 deletions(-) --- a/fs/hugetlbfs/inode.c~mm-hugetlbfs-fix-error-handling-when-setting-up-mounts +++ a/fs/hugetlbfs/inode.c @@ -1461,28 +1461,41 @@ static int __init init_hugetlbfs_fs(void sizeof(struct hugetlbfs_inode_info), 0, SLAB_ACCOUNT, init_once); if (hugetlbfs_inode_cachep == NULL) - goto out2; + goto out; error = register_filesystem(&hugetlbfs_fs_type); if (error) - goto out; + goto out_free; + + /* default hstate mount is required */ + mnt = mount_one_hugetlbfs(&hstates[default_hstate_idx]); + if (IS_ERR(mnt)) { + error = PTR_ERR(mnt); + goto out_unreg; + } + hugetlbfs_vfsmount[default_hstate_idx] = mnt; + /* other hstates are optional */ i = 0; for_each_hstate(h) { + if (i == default_hstate_idx) + continue; + mnt = mount_one_hugetlbfs(h); - if (IS_ERR(mnt) && i == 0) { - error = PTR_ERR(mnt); - goto out; - } - hugetlbfs_vfsmount[i] = mnt; + if (IS_ERR(mnt)) + hugetlbfs_vfsmount[i] = NULL; + else + hugetlbfs_vfsmount[i] = mnt; i++; } return 0; - out: + out_unreg: + (void)unregister_filesystem(&hugetlbfs_fs_type); + out_free: kmem_cache_destroy(hugetlbfs_inode_cachep); - out2: + out: return error; } fs_initcall(init_hugetlbfs_fs) _