Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

Pull networking fixes from David Miller:

 1) Frag and UDP handling fixes in i40e driver, from Amritha Nambiar and
    Alexander Duyck.

 2) Undo unintentional UAPI change in netfilter conntrack, from Florian
    Westphal.

 3) Revert a change to how error codes are returned from
    dev_get_valid_name(), it broke some apps.

 4) Cannot cache routes for ipv6 tunnels in the tunnel is ipv4/ipv6
    dual-stack. From Eli Cooper.

 5) Fix missed PMTU updates in geneve, from Xin Long.

 6) Cure double free in macvlan, from Gao Feng.

 7) Fix heap out-of-bounds write in rds_message_alloc_sgs(), from
    Mohamed Ghannam.

 8) FEC bug fixes from FUgang Duan (mis-accounting of dev_id, missed
    deferral of probe when the regulator is not ready yet).

 9) Missing DMA mapping error checks in 3c59x, from Neil Horman.

10) Turn off Broadcom tags for some b53 switches, from Florian Fainelli.

11) Fix OOPS when get_target_net() is passed an SKB whose NETLINK_CB()
    isn't initialized. From Andrei Vagin.

12) Fix crashes in fib6_add(), from Wei Wang.

13) PMTU bug fixes in SCTP from Marcelo Ricardo Leitner.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (56 commits)
  sh_eth: fix TXALCR1 offsets
  mdio-sun4i: Fix a memory leak
  phylink: mark expected switch fall-throughs in phylink_mii_ioctl
  sctp: fix the handling of ICMP Frag Needed for too small MTUs
  sctp: do not retransmit upon FragNeeded if PMTU discovery is disabled
  xen-netfront: enable device after manual module load
  bnxt_en: Fix the 'Invalid VF' id check in bnxt_vf_ndo_prep routine.
  bnxt_en: Fix population of flow_type in bnxt_hwrm_cfa_flow_alloc()
  sh_eth: fix SH7757 GEther initialization
  net: fec: free/restore resource in related probe error pathes
  uapi/if_ether.h: prevent redefinition of struct ethhdr
  ipv6: fix general protection fault in fib6_add()
  RDS: null pointer dereference in rds_atomic_free_op
  sh_eth: fix TSU resource handling
  net: stmmac: enable EEE in MII, GMII or RGMII only
  rtnetlink: give a user socket to get_target_net()
  MAINTAINERS: Update my email address.
  can: ems_usb: improve error reporting for error warning and error passive
  can: flex_can: Correct the checking for frame length in flexcan_start_xmit()
  can: gs_usb: fix return value of the "set_bittiming" callback
  ...

1 files changed, 16 insertions, 12 deletions

diff --git a/net/sctp/input.c b/net/sctp/input.c
index 621b5ca3fd1c..141c9c466ec1 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -399,20 +399,24 @@ void sctp_icmp_frag_needed(struct sock *sk, struct sctp_association *asoc,
 		return;
 	}
 
-	if (t->param_flags & SPP_PMTUD_ENABLE) {
-		/* Update transports view of the MTU */
-		sctp_transport_update_pmtu(t, pmtu);
-
-		/* Update association pmtu. */
-		sctp_assoc_sync_pmtu(asoc);
-	}
+	if (!(t->param_flags & SPP_PMTUD_ENABLE))
+		/* We can't allow retransmitting in such case, as the
+		 * retransmission would be sized just as before, and thus we
+		 * would get another icmp, and retransmit again.
+		 */
+		return;
 
-	/* Retransmit with the new pmtu setting.
-	 * Normally, if PMTU discovery is disabled, an ICMP Fragmentation
-	 * Needed will never be sent, but if a message was sent before
-	 * PMTU discovery was disabled that was larger than the PMTU, it
-	 * would not be fragmented, so it must be re-transmitted fragmented.
+	/* Update transports view of the MTU. Return if no update was needed.
+	 * If an update wasn't needed/possible, it also doesn't make sense to
+	 * try to retransmit now.
 	 */
+	if (!sctp_transport_update_pmtu(t, pmtu))
+		return;
+
+	/* Update association pmtu. */
+	sctp_assoc_sync_pmtu(asoc);
+
+	/* Retransmit with the new pmtu setting. */
 	sctp_retransmit(&asoc->outqueue, t, SCTP_RTXR_PMTUD);
 }