From: Eric W. Biederman <ebiederm@xmission.com>
Date: Fri, 15 Mar 2013 08:03:33 +0000 (-0700)
Subject: scm: Require CAP_SYS_ADMIN over the current pidns to spoof pids.
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=92f28d973cce45ef5823209aab3138eb45d8b349;p=linux-beck.git

scm: Require CAP_SYS_ADMIN over the current pidns to spoof pids.

Don't allow spoofing pids over unix domain sockets in the corner
cases where a user has created a user namespace but has not yet
created a pid namespace.

Cc: stable@vger.kernel.org
Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---

diff --git a/net/core/scm.c b/net/core/scm.c
index 905dcc6ad1e3..2dc6cdaaae8a 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -24,6 +24,7 @@
 #include <linux/interrupt.h>
 #include <linux/netdevice.h>
 #include <linux/security.h>
+#include <linux/pid_namespace.h>
 #include <linux/pid.h>
 #include <linux/nsproxy.h>
 #include <linux/slab.h>
@@ -52,7 +53,8 @@ static __inline__ int scm_check_creds(struct ucred *creds)
 	if (!uid_valid(uid) || !gid_valid(gid))
 		return -EINVAL;
 
-	if ((creds->pid == task_tgid_vnr(current) || nsown_capable(CAP_SYS_ADMIN)) &&
+	if ((creds->pid == task_tgid_vnr(current) ||
+	     ns_capable(current->nsproxy->pid_ns->user_ns, CAP_SYS_ADMIN)) &&
 	    ((uid_eq(uid, cred->uid)   || uid_eq(uid, cred->euid) ||
 	      uid_eq(uid, cred->suid)) || nsown_capable(CAP_SETUID)) &&
 	    ((gid_eq(gid, cred->gid)   || gid_eq(gid, cred->egid) ||