From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f68.google.com ([74.125.82.68]:36421 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751271AbcJZRLK (ORCPT ); Wed, 26 Oct 2016 13:11:10 -0400 From: Amir Goldstein To: Miklos Szeredi Cc: Vivek Goyal , Andreas Gruenbacher , linux-unionfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH] ovl: update S_ISGID when setting posix ACLs Date: Wed, 26 Oct 2016 20:10:40 +0300 Message-Id: <1477501840-25066-1-git-send-email-amir73il@gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Since operations on upper are performed using mounter's credentials, we need to call posix_acl_update_mode() with user credentials on overlay inode to possibly copy-up and clear setgid bit, before setting extended attributes on upper inode. This change fixes xfstest generic/375, which failed to clear the setgid bit in the following test case over overlayfs: touch $testfile chown 100:100 $testfile chmod 2755 $testfile _runas -u 100 -g 101 -- setfacl -m u::rwx,g::rwx,o::rwx $testfile Signed-off-by: Amir Goldstein --- fs/overlayfs/super.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 30263a5..16cc844 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -522,6 +522,22 @@ static unsigned int ovl_split_lowerdirs(char *str) return ctr; } +static int +ovl_set_mode(struct dentry *dentry, umode_t mode) +{ + struct iattr iattr; + int err; + + if (mode == d_inode(dentry)->i_mode) + return 0; + + iattr.ia_valid = ATTR_MODE | ATTR_CTIME; + iattr.ia_mode = mode; + iattr.ia_ctime = current_time(d_inode(dentry)); + + return ovl_setattr(dentry, &iattr); +} + static int __maybe_unused ovl_posix_acl_xattr_get(const struct xattr_handler *handler, struct dentry *dentry, struct inode *inode, @@ -560,6 +576,18 @@ ovl_posix_acl_xattr_set(const struct xattr_handler *handler, if (!inode_owner_or_capable(inode)) goto out_acl_release; + if (handler->flags == ACL_TYPE_ACCESS) { + umode_t mode; + struct posix_acl *newacl = acl; + + err = posix_acl_update_mode(inode, &mode, &newacl); + if (err) + goto out_acl_release; + err = ovl_set_mode(dentry, mode); + if (err) + goto out_acl_release; + } + posix_acl_release(acl); err = ovl_xattr_set(dentry, handler->name, value, size, flags); -- 2.7.4