bonding: prevent out of bound accesses

commit f87fda00b6ed232a817c655b8d179b48bde8fdbe upstream.

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

Same problem with mac_bcast[] and mac_v6_allmcast[] in bond_alb.c :
Although the 8-byte alignment was there, KASan would detect out
of bound accesses.

Fixes: 815117adaf5b ("bonding: use ether_addr_equal_unaligned for bond addr compare")
Fixes: bb54e58929f3 ("bonding: Verify RX LACPDU has proper dest mac-addr")
Fixes: 885a136c52a8 ("bonding: use compare_ether_addr_64bits() in ALB")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Acked-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16:
 - Adjust filename
 - Drop change to bond_params::ad_actor_system
 - Fix one more copy of null_mac_addr to use eth_zero_addr()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c
index 0dfeaf5da3f2c914e2fd43e40d4bf4f3d8aff079..f65bfbbefd286b9603be7ddcc13c6edc680ccbd4 100644 (file)
--- a/drivers/net/bonding/bond_3ad.c
+++ b/drivers/net/bonding/bond_3ad.c
@@ -95,11 +95,14 @@
 #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 + 2] __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 + 2] __long_aligned =
+       MULTICAST_LACPDU_ADDR;
 
 /* ================= main 802.3ad protocol functions ================== */
 static int ad_lacpdu_send(struct port *port);
@@ -1614,7 +1617,7 @@ 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;
@@ -1636,7 +1639,7 @@ 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;
        }
@@ -1671,7 +1674,7 @@ static void ad_initialize_port(struct port *port, int lacp_fast)
        if (port) {
                port->actor_port_number = 1;
                port->actor_port_priority = 0xff;
-               port->actor_system = null_mac_addr;
+               eth_zero_addr(port->actor_system.mac_addr_value);
                port->actor_system_priority = 0xffff;
                port->actor_port_aggregator_identifier = 0;
                port->ntt = false;

diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
index 76c0dade233f904324631dba34be0f370d193179..cd440dfffad1284d1415d0ec0c5f6e7452b3ffa1 100644 (file)
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c
@@ -44,13 +44,10 @@
 
 
 
-#ifndef __long_aligned
-#define __long_aligned __attribute__((aligned((sizeof(long)))))
-#endif
-static const u8 mac_bcast[ETH_ALEN] __long_aligned = {
+static const u8 mac_bcast[ETH_ALEN + 2] __long_aligned = {
        0xff, 0xff, 0xff, 0xff, 0xff, 0xff
 };
-static const u8 mac_v6_allmcast[ETH_ALEN] __long_aligned = {
+static const u8 mac_v6_allmcast[ETH_ALEN + 2] __long_aligned = {
        0x33, 0x33, 0x00, 0x00, 0x00, 0x01
 };
 static const int alb_delta_in_ticks = HZ / ALB_TIMER_TICKS_PER_SEC;

diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
index 0b4d9cde0b05e33a34e5deaec3b28126f1cba8e1..0aadbae041f46747f376a8bd75121de2c025780b 100644 (file)
--- a/drivers/net/bonding/bonding.h
+++ b/drivers/net/bonding/bonding.h
@@ -41,6 +41,9 @@
 
 #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.