[PATCH] unshare: Error if passed unsupported flags

A bare bones trivial patch to ensure we always get -EINVAL on the
unsupported cases for sys_unshare.  If this goes in before 2.6.16 it allows
us to forward compatible with future applications using sys_unshare.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: JANAK DESAI <janak@us.ibm.com>
Cc: <stable@kerenl.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/kernel/fork.c b/kernel/fork.c
index b373322ca4977a632bed40a38de125e9db482228..9bd7b65ee418b8a05498d3cd8b89c53dcb66e6fc 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1534,6 +1534,12 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)
 
        check_unshare_flags(&unshare_flags);
 
+       /* Return -EINVAL for all unsupported flags */
+       err = -EINVAL;
+       if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND|
+                               CLONE_VM|CLONE_FILES|CLONE_SYSVSEM))
+               goto bad_unshare_out;
+
        if ((err = unshare_thread(unshare_flags)))
                goto bad_unshare_out;
        if ((err = unshare_fs(unshare_flags, &new_fs)))