From fd3220d37b1f6f0cab6142d98b0e6c4082e63299 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Mon, 31 Oct 2016 14:42:14 +0100 Subject: ovl: update S_ISGID when setting posix ACLs This change fixes xfstest generic/375, which failed to clear the setgid bit in the following test case on overlayfs: touch $testfile chown 100:100 $testfile chmod 2755 $testfile _runas -u 100 -g 101 -- setfacl -m u::rwx,g::rwx,o::rwx $testfile Reported-by: Amir Goldstein Signed-off-by: Miklos Szeredi Tested-by: Amir Goldstein Fixes: d837a49bd57f ("ovl: fix POSIX ACL setting") Cc: # v4.8 --- fs/overlayfs/super.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'fs') diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index bcf3965be819..edd46a0e951d 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -1037,6 +1037,21 @@ ovl_posix_acl_xattr_set(const struct xattr_handler *handler, posix_acl_release(acl); + /* + * Check if sgid bit needs to be cleared (actual setacl operation will + * be done with mounter's capabilities and so that won't do it for us). + */ + if (unlikely(inode->i_mode & S_ISGID) && + handler->flags == ACL_TYPE_ACCESS && + !in_group_p(inode->i_gid) && + !capable_wrt_inode_uidgid(inode, CAP_FSETID)) { + struct iattr iattr = { .ia_valid = ATTR_KILL_SGID }; + + err = ovl_setattr(dentry, &iattr); + if (err) + return err; + } + err = ovl_xattr_set(dentry, handler->name, value, size, flags); if (!err) ovl_copyattr(ovl_inode_real(inode, NULL), inode); -- cgit v1.2.3-59-g8ed1b