releases/4.14.117/ipv6-invert-flowlabel-sharing-check-in-process-and-user-mode.patch

   1 From foo@baz Sat 04 May 2019 11:25:56 AM CEST
   2 From: Willem de Bruijn <willemb@google.com>
   3 Date: Thu, 25 Apr 2019 12:06:54 -0400
   4 Subject: ipv6: invert flowlabel sharing check in process and user mode
   5
   6 From: Willem de Bruijn <willemb@google.com>
   7
   8 [ Upstream commit 95c169251bf734aa555a1e8043e4d88ec97a04ec ]
   9
  10 A request for a flowlabel fails in process or user exclusive mode must
  11 fail if the caller pid or uid does not match. Invert the test.
  12
  13 Previously, the test was unsafe wrt PID recycling, but indeed tested
  14 for inequality: fl1->owner != fl->owner
  15
  16 Fixes: 4f82f45730c68 ("net ip6 flowlabel: Make owner a union of struct pid* and kuid_t")
  17 Signed-off-by: Willem de Bruijn <willemb@google.com>
  18 Signed-off-by: David S. Miller <davem@davemloft.net>
  19 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  20 ---
  21  net/ipv6/ip6_flowlabel.c |    4 ++--
  22  1 file changed, 2 insertions(+), 2 deletions(-)
  23
  24 --- a/net/ipv6/ip6_flowlabel.c
  25 +++ b/net/ipv6/ip6_flowlabel.c
  26 @@ -640,9 +640,9 @@ recheck:
  27                                 if (fl1->share == IPV6_FL_S_EXCL ||
  28                                     fl1->share != fl->share ||
  29                                     ((fl1->share == IPV6_FL_S_PROCESS) &&
  30 -                                    (fl1->owner.pid == fl->owner.pid)) ||
  31 +                                    (fl1->owner.pid != fl->owner.pid)) ||
  32                                     ((fl1->share == IPV6_FL_S_USER) &&
  33 -                                    uid_eq(fl1->owner.uid, fl->owner.uid)))
  34 +                                    !uid_eq(fl1->owner.uid, fl->owner.uid)))
  35                                         goto release;
  36
  37                                 err = -ENOMEM;