ipv6: invert flowlabel sharing check in process and user mode

[ Upstream commit 95c169251bf734aa555a1e8043e4d88ec97a04ec ]

A request for a flowlabel fails in process or user exclusive mode must
fail if the caller pid or uid does not match. Invert the test.

Previously, the test was unsafe wrt PID recycling, but indeed tested
for inequality: fl1->owner != fl->owner

Fixes: 4f82f45730c68 ("net ip6 flowlabel: Make owner a union of struct pid* and kuid_t")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c
index f9a22acc69139abbb0504a0925b75af666319dae..c6061f7343f1353a3f45b693b630db24553b76d2 100644 (file)
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -639,9 +639,9 @@ recheck:
                                if (fl1->share == IPV6_FL_S_EXCL ||
                                    fl1->share != fl->share ||
                                    ((fl1->share == IPV6_FL_S_PROCESS) &&
-                                    (fl1->owner.pid == fl->owner.pid)) ||
+                                    (fl1->owner.pid != fl->owner.pid)) ||
                                    ((fl1->share == IPV6_FL_S_USER) &&
-                                    uid_eq(fl1->owner.uid, fl->owner.uid)))
+                                    !uid_eq(fl1->owner.uid, fl->owner.uid)))
                                        goto release;
 
                                err = -ENOMEM;