[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>

1 files changed, 6 insertions, 0 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index b373322ca497..9bd7b65ee418 100644
--- 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)))