From: Eric Dumazet <eduma...@google.com>

ether_addr_equal_64bits() requires some care about its arguments,
namely that 8 bytes might be read, even if last 2 byte values are not
used.

KASan detected a violation with null_mac_addr and lacpdu_mcast_addr
in bond_3ad.c

Fixes: 815117adaf5b ("bonding: use ether_addr_equal_unaligned for bond addr 
compare")
Fixes: bb54e58929f3 ("bonding: Verify RX LACPDU has proper dest mac-addr")
Signed-off-by: Eric Dumazet <eduma...@google.com>
Reported-by: Dmitry Vyukov <dvyu...@google.com>
---
 drivers/net/bonding/bond_3ad.c |   11 +++++++----
 drivers/net/bonding/bond_alb.c |    3 ---
 include/net/bonding.h          |    7 ++++++-
 3 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c
index ca81f46ea1aa..8ad491ab1d01 100644
--- a/drivers/net/bonding/bond_3ad.c
+++ b/drivers/net/bonding/bond_3ad.c
@@ -101,11 +101,14 @@ enum ad_link_speed_type {
 #define MAC_ADDRESS_EQUAL(A, B)        \
        ether_addr_equal_64bits((const u8 *)A, (const u8 *)B)
 
-static struct mac_addr null_mac_addr = { { 0, 0, 0, 0, 0, 0 } };
+static const u8 null_mac_addr[ETH_ALEN] __long_aligned = {
+       0, 0, 0, 0, 0, 0
+};
 static u16 ad_ticks_per_sec;
 static const int ad_delta_in_ticks = (AD_TIMER_INTERVAL * HZ) / 1000;
 
-static const u8 lacpdu_mcast_addr[ETH_ALEN] = MULTICAST_LACPDU_ADDR;
+static const u8 lacpdu_mcast_addr[ETH_ALEN] __long_aligned =
+       MULTICAST_LACPDU_ADDR;
 
 /* ================= main 802.3ad protocol functions ================== */
 static int ad_lacpdu_send(struct port *port);
@@ -1739,7 +1742,7 @@ static void ad_clear_agg(struct aggregator *aggregator)
                aggregator->is_individual = false;
                aggregator->actor_admin_aggregator_key = 0;
                aggregator->actor_oper_aggregator_key = 0;
-               aggregator->partner_system = null_mac_addr;
+               eth_zero_addr(aggregator->partner_system.mac_addr_value);
                aggregator->partner_system_priority = 0;
                aggregator->partner_oper_aggregator_key = 0;
                aggregator->receive_state = 0;
@@ -1761,7 +1764,7 @@ static void ad_initialize_agg(struct aggregator 
*aggregator)
        if (aggregator) {
                ad_clear_agg(aggregator);
 
-               aggregator->aggregator_mac_address = null_mac_addr;
+               
eth_zero_addr(aggregator->aggregator_mac_address.mac_addr_value);
                aggregator->aggregator_identifier = 0;
                aggregator->slave = NULL;
        }
diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
index c5ac160a8ae9..26beed070bf0 100644
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c
@@ -42,9 +42,6 @@
 
 
 
-#ifndef __long_aligned
-#define __long_aligned __attribute__((aligned((sizeof(long)))))
-#endif
 static const u8 mac_bcast[ETH_ALEN] __long_aligned = {
        0xff, 0xff, 0xff, 0xff, 0xff, 0xff
 };
diff --git a/include/net/bonding.h b/include/net/bonding.h
index 791800ddd6d9..6360c259da6d 100644
--- a/include/net/bonding.h
+++ b/include/net/bonding.h
@@ -34,6 +34,9 @@
 
 #define BOND_DEFAULT_MIIMON    100
 
+#ifndef __long_aligned
+#define __long_aligned __attribute__((aligned((sizeof(long)))))
+#endif
 /*
  * Less bad way to call ioctl from within the kernel; this needs to be
  * done some other way to get the call out of interrupt context.
@@ -138,7 +141,9 @@ struct bond_params {
        struct reciprocal_value reciprocal_packets_per_slave;
        u16 ad_actor_sys_prio;
        u16 ad_user_port_key;
-       u8 ad_actor_system[ETH_ALEN];
+
+       /* 2 bytes of padding : see ether_addr_equal_64bits() */
+       u8 ad_actor_system[ETH_ALEN + 2];
 };
 
 struct bond_parm_tbl {


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