From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:48556 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936971AbeE1K3K (ORCPT ); Mon, 28 May 2018 06:29:10 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jun Piao , Alex Chen , Mark Fasheh , Joel Becker , Junxiao Bi , Joseph Qi , Changwei Ge , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH 4.9 066/329] ocfs2/acl: use ip_xattr_sem to protect getting extended attribute Date: Mon, 28 May 2018 11:59:55 +0200 Message-Id: <20180528100248.297761350@linuxfoundation.org> In-Reply-To: <20180528100241.796630982@linuxfoundation.org> References: <20180528100241.796630982@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: piaojun [ Upstream commit 16c8d569f5704a84164f30ff01b29879f3438065 ] The race between *set_acl and *get_acl will cause getting incomplete xattr data as below: processA processB ocfs2_set_acl ocfs2_xattr_set __ocfs2_xattr_set_handle ocfs2_get_acl_nolock ocfs2_xattr_get_nolock: processB may get incomplete xattr data if processA hasn't set_acl done. So we should use 'ip_xattr_sem' to protect getting extended attribute in ocfs2_get_acl_nolock(), as other processes could be changing it concurrently. Link: http://lkml.kernel.org/r/5A5DDCFF.7030001@huawei.com Signed-off-by: Jun Piao Reviewed-by: Alex Chen Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Joseph Qi Cc: Changwei Ge Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- fs/ocfs2/acl.c | 6 ++++++ fs/ocfs2/xattr.c | 2 ++ 2 files changed, 8 insertions(+) --- a/fs/ocfs2/acl.c +++ b/fs/ocfs2/acl.c @@ -314,7 +314,9 @@ struct posix_acl *ocfs2_iop_get_acl(stru return ERR_PTR(ret); } + down_read(&OCFS2_I(inode)->ip_xattr_sem); acl = ocfs2_get_acl_nolock(inode, type, di_bh); + up_read(&OCFS2_I(inode)->ip_xattr_sem); ocfs2_inode_unlock(inode, 0); brelse(di_bh); @@ -333,7 +335,9 @@ int ocfs2_acl_chmod(struct inode *inode, if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL)) return 0; + down_read(&OCFS2_I(inode)->ip_xattr_sem); acl = ocfs2_get_acl_nolock(inode, ACL_TYPE_ACCESS, bh); + up_read(&OCFS2_I(inode)->ip_xattr_sem); if (IS_ERR(acl) || !acl) return PTR_ERR(acl); ret = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode); @@ -364,8 +368,10 @@ int ocfs2_init_acl(handle_t *handle, if (!S_ISLNK(inode->i_mode)) { if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) { + down_read(&OCFS2_I(dir)->ip_xattr_sem); acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT, dir_bh); + up_read(&OCFS2_I(dir)->ip_xattr_sem); if (IS_ERR(acl)) return PTR_ERR(acl); } --- a/fs/ocfs2/xattr.c +++ b/fs/ocfs2/xattr.c @@ -638,9 +638,11 @@ int ocfs2_calc_xattr_init(struct inode * si->value_len); if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) { + down_read(&OCFS2_I(dir)->ip_xattr_sem); acl_len = ocfs2_xattr_get_nolock(dir, dir_bh, OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT, "", NULL, 0); + up_read(&OCFS2_I(dir)->ip_xattr_sem); if (acl_len > 0) { a_size = ocfs2_xattr_entry_real_size(0, acl_len); if (S_ISDIR(mode))