fix umask when noACL kernel meets extN tuned for ACLs
Fix insecure default behaviour reported by Tigran Aivazian: if an ext2
or ext3 filesystem is tuned to mount with "acl", but mounted by
a kernel built without ACL support, then umask was ignored when creating
inodes - though root or user has umask 022, touch creates files as 0666,
and mkdir creates directories as 0777.
This appears to have worked right until 2.6.11, when a fix to the default
mode on symlinks (always 0777) assumed VFS applies umask: which it does,
unless the mount is marked for ACLs; but ext set MS_POSIXACL in
s_flags according to s_mount_opt set according to def_mount_opts.
We could revert to the 2.6.10 ext_init_acl (adding an S_ISLNK test);
but other filesystems only set MS_POSIXACL when ACLs are configured. We
could fix this at another level; but it seems most robust to avoid setting
the s_mount_opt flag in the first place (at the expense of more ifdefs).
Likewise don't set the XATTR_USER flag when built without XATTR support.
Signed-off-by: Hugh Dickins <firstname.lastname@example.org>
Acked-by: Andreas Gruenbacher <email@example.com>
Cc: Tigran Aivazian <firstname.lastname@example.org>
Signed-off-by: Chris Wright <email@example.com>
Signed-off-by: Greg Kroah-Hartman <firstname.lastname@example.org>