Merge tag 'net-6.2-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Paolo Abeni:
 "Including fixes from can and ipsec subtrees.

  Current release - regressions:

   - sched: fix off by one in htb_activate_prios()

   - eth: mana: fix accessing freed irq affinity_hint

   - eth: ice: fix out-of-bounds KASAN warning in virtchnl

  Current release - new code bugs:

   - eth: mtk_eth_soc: enable special tag when any MAC uses DSA

  Previous releases - always broken:

   - core: fix sk->sk_txrehash default

   - neigh: make sure used and confirmed times are valid

   - mptcp: be careful on subflow status propagation on errors

   - xfrm: prevent potential spectre v1 gadget in xfrm_xlate32_attr()

   - phylink: move phy_device_free() to correctly release phy device

   - eth: mlx5:
      - fix crash unsetting rx-vlan-filter in switchdev mode
      - fix hang on firmware reset
      - serialize module cleanup with reload and remove"

* tag 'net-6.2-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (57 commits)
  selftests: forwarding: lib: quote the sysctl values
  net: mscc: ocelot: fix all IPv6 getting trapped to CPU when PTP timestamping is used
  rds: rds_rm_zerocopy_callback() use list_first_entry()
  net: txgbe: Update support email address
  selftests: Fix failing VXLAN VNI filtering test
  selftests: mptcp: stop tests earlier
  selftests: mptcp: allow more slack for slow test-case
  mptcp: be careful on subflow status propagation on errors
  mptcp: fix locking for in-kernel listener creation
  mptcp: fix locking for setsockopt corner-case
  mptcp: do not wait for bare sockets' timeout
  net: ethernet: mtk_eth_soc: fix DSA TX tag hwaccel for switch port 0
  nfp: ethtool: fix the bug of setting unsupported port speed
  txhash: fix sk->sk_txrehash default
  net: ethernet: mtk_eth_soc: fix wrong parameters order in __xdp_rxq_info_reg()
  net: ethernet: mtk_eth_soc: enable special tag when any MAC uses DSA
  net: sched: sch: Fix off by one in htb_activate_prios()
  igc: Add ndo_tx_timeout support
  net: mana: Fix accessing freed irq affinity_hint
  hv_netvsc: Allocate memory in netvsc_dma_map() with GFP_ATOMIC
  ...

1 files changed, 40 insertions, 0 deletions

diff --git a/net/can/j1939/address-claim.c b/net/can/j1939/address-claim.c
index f33c47327927..ca4ad6cdd5cb 100644
--- a/net/can/j1939/address-claim.c
+++ b/net/can/j1939/address-claim.c
@@ -165,6 +165,46 @@ static void j1939_ac_process(struct j1939_priv *priv, struct sk_buff *skb)
 	 * leaving this function.
 	 */
 	ecu = j1939_ecu_get_by_name_locked(priv, name);
+
+	if (ecu && ecu->addr == skcb->addr.sa) {
+		/* The ISO 11783-5 standard, in "4.5.2 - Address claim
+		 * requirements", states:
+		 *   d) No CF shall begin, or resume, transmission on the
+		 *      network until 250 ms after it has successfully claimed
+		 *      an address except when responding to a request for
+		 *      address-claimed.
+		 *
+		 * But "Figure 6" and "Figure 7" in "4.5.4.2 - Address-claim
+		 * prioritization" show that the CF begins the transmission
+		 * after 250 ms from the first AC (address-claimed) message
+		 * even if it sends another AC message during that time window
+		 * to resolve the address contention with another CF.
+		 *
+		 * As stated in "4.4.2.3 - Address-claimed message":
+		 *   In order to successfully claim an address, the CF sending
+		 *   an address claimed message shall not receive a contending
+		 *   claim from another CF for at least 250 ms.
+		 *
+		 * As stated in "4.4.3.2 - NAME management (NM) message":
+		 *   1) A commanding CF can
+		 *      d) request that a CF with a specified NAME transmit
+		 *         the address-claimed message with its current NAME.
+		 *   2) A target CF shall
+		 *      d) send an address-claimed message in response to a
+		 *         request for a matching NAME
+		 *
+		 * Taking the above arguments into account, the 250 ms wait is
+		 * requested only during network initialization.
+		 *
+		 * Do not restart the timer on AC message if both the NAME and
+		 * the address match and so if the address has already been
+		 * claimed (timer has expired) or the AC message has been sent
+		 * to resolve the contention with another CF (timer is still
+		 * running).
+		 */
+		goto out_ecu_put;
+	}
+
 	if (!ecu && j1939_address_is_unicast(skcb->addr.sa))
 		ecu = j1939_ecu_create_locked(priv, name);