[ 52/68] af_unix: dont send SCM_CREDENTIAL when dest socket is NULL

Greg Kroah-Hartman
2013-04-02T22:21:42Z

From: dingtianhong <dingtianhong@huawei.com>

[ Upstream commit 14134f6584212d585b310ce95428014b653dfaf6 ]

SCM_SCREDENTIALS should apply to write() syscalls only either source or destination
socket asserted SOCK_PASSCRED. The original implememtation in maybe_add_creds is wrong,
and breaks several LSB testcases ( i.e. /tset/LSB.os/netowkr/recvfrom/T.recvfrom).

Origionally-authored-by: Karel Srot <ksrot@redhat.com>
Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/unix/af_unix.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1414,8 +1414,8 @@ static void maybe_add_creds(struct sk_bu
if (UNIXCB(skb).cred)
return;
if (test_bit(SOCK_PASSCRED, &sock->flags) ||
- !other->sk_socket ||
- test_bit(SOCK_PASSCRED, &other->sk_socket->flags)) {
+ (other->sk_socket &&
+ test_bit(SOCK_PASSCRED, &other->sk_socket->flags))) {
UNIXCB(skb).pid = get_pid(task_tgid(current));
UNIXCB(skb).cred = get_current_cred();
}