[PATCH] unshare: Error if passed unsupported flags

From: ebiederm@xmission.com (Eric W. Biederman)
To: Andrew Morton <akpm@osdl.org>
Cc: Oleg Nesterov <oleg@tv-sign.ru>,
	torvalds@osdl.org, linux-kernel@vger.kernel.org,
	janak@us.ibm.com, viro@ftp.linux.org.uk, hch@lst.de,
	mtk-manpages@gmx.net, ak@muc.de, paulus@samba.org
Subject: [PATCH] unshare: Error if passed unsupported flags
Date: Sat, 18 Mar 2006 08:10:16 -0700	[thread overview]
Message-ID: <m13bhf3i1z.fsf_-_@ebiederm.dsl.xmission.com> (raw)
In-Reply-To: <20060317125607.78a5dbe4.akpm@osdl.org> (Andrew Morton's message of "Fri, 17 Mar 2006 12:56:07 -0800")


This patch does 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>


---

 kernel/fork.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

46868b4b6ebeb9042dded68a6f6301ffe06820c9

diff --git a/kernel/fork.c b/kernel/fork.c
index 46060cb..411b10d 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1535,6 +1535,12 @@ asmlinkage long sys_unshare(unsigned lon
 	struct sem_undo_list *new_ulist = NULL;
 
 	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;
-- 
1.2.4.g2d33

