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 1a83031bcddddfc9cd5af64d161ef3f342ab3102..bd34cf1b82a36b05a037498f18d6c6c39e6ad9d6 100644 (file)
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -629,9 +629,9 @@ 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;