userns: Convert net/core/scm.c to use kuids and kgids

With the existence of kuid_t and kgid_t we can take this further
and remove the usage of struct cred altogether, ensuring we
don't get cache line misses from reference counts.   For now
however start simply and do a straight forward conversion
I can be certain is correct.

In cred_to_ucred use from_kuid_munged and from_kgid_munged
as these values are going directly to userspace and we want to use
the userspace safe values not -1 when reporting a value that does not
map.  The earlier conversion that used from_kuid was buggy in that
respect.  Oops.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/net/core/sock.c b/net/core/sock.c
index 6b654b3ddfda..9c7fe4ff30fc 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -868,8 +868,8 @@ void cred_to_ucred(struct pid *pid, const struct cred *cred,
         if (cred) {
                 struct user_namespace *current_ns = current_user_ns();
 
-                ucred->uid = from_kuid(current_ns, cred->euid);
-                ucred->gid = from_kgid(current_ns, cred->egid);
+                ucred->uid = from_kuid_munged(current_ns, cred->euid);
+                ucred->gid = from_kgid_munged(current_ns, cred->egid);
         }
 }
 EXPORT_SYMBOL_GPL(cred_to_ucred);