[PATCH net] bonding: prevent out of bound accesses

[PATCH net] bonding: prevent out of bound accesses

[Eric Dumazet]

From: Eric Dumazet <edumazet@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 <edumazet@google.com>
Reported-by: Dmitry Vyukov <dvyukov@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 {

Re: [PATCH net] bonding: prevent out of bound accesses

[Dmitry Vyukov]

On Thu, Jun 30, 2016 at 2:56 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
> From: Eric Dumazet <edumazet@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 <edumazet@google.com>
> Reported-by: Dmitry Vyukov <dvyukov@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
> +};

__long_aligned won't prevent KASAN from barking, it's still 6 bytes
but we are reading 8.
Can we please do "ETH_ALEN + 2" as below?


>  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 {
>
>

Re: [PATCH net] bonding: prevent out of bound accesses

[Nikolay Aleksandrov]

On 30/06/16 14:56, Eric Dumazet wrote:
> From: Eric Dumazet <edumazet@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 <edumazet@google.com>
> Reported-by: Dmitry Vyukov <dvyukov@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(-)
> 

Good catch,
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>

Re: [PATCH net] bonding: prevent out of bound accesses

[Eric Dumazet]

On Thu, 2016-06-30 at 15:04 +0200, Dmitry Vyukov wrote:
> On Thu, Jun 30, 2016 at 2:56 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
> > From: Eric Dumazet <edumazet@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 <edumazet@google.com>
> > Reported-by: Dmitry Vyukov <dvyukov@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
> > +};
> 
> __long_aligned won't prevent KASAN from barking, it's still 6 bytes
> but we are reading 8.
> Can we please do "ETH_ALEN + 2" as below?

Really ?

sizeof(null_mac_addr) is 8, how KASan would decide it is 6 bytes ?

nm -v drivers/net/bonding/bonding.ko|grep -3 null_mac_addr

000000000000084a r __UNIQUE_ID_mode17
0000000000000850 r tmpl.46263
0000000000000860 r lacpdu_mcast_addr
0000000000000868 r null_mac_addr
0000000000000870 r mac_v6_allmcast
0000000000000878 r mac_bcast
0000000000000880 r slave_sysfs_ops

Same trick was used in
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=885a136c52a8871175477baf3903e1c38751b35a

Re: [PATCH net] bonding: prevent out of bound accesses

[Dmitry Vyukov]

On Thu, Jun 30, 2016 at 3:25 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
> On Thu, 2016-06-30 at 15:04 +0200, Dmitry Vyukov wrote:
>> On Thu, Jun 30, 2016 at 2:56 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
>> > From: Eric Dumazet <edumazet@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 <edumazet@google.com>
>> > Reported-by: Dmitry Vyukov <dvyukov@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
>> > +};
>>
>> __long_aligned won't prevent KASAN from barking, it's still 6 bytes
>> but we are reading 8.
>> Can we please do "ETH_ALEN + 2" as below?
>
> Really ?
>
> sizeof(null_mac_addr) is 8, how KASan would decide it is 6 bytes ?
>
> nm -v drivers/net/bonding/bonding.ko|grep -3 null_mac_addr
>
> 000000000000084a r __UNIQUE_ID_mode17
> 0000000000000850 r tmpl.46263
> 0000000000000860 r lacpdu_mcast_addr
> 0000000000000868 r null_mac_addr
> 0000000000000870 r mac_v6_allmcast
> 0000000000000878 r mac_bcast
> 0000000000000880 r slave_sysfs_ops


What does nm -S say?
I've tried to compile a sample program with gcc6 and
__attribute__((aligned(8))) does in fact force alignment of start of
the symbol, but size still stays 6. (and asan still barks on my test
program).

Re: [PATCH net] bonding: prevent out of bound accesses

[Eric Dumazet]

On Thu, 2016-06-30 at 15:35 +0200, Dmitry Vyukov wrote:

> 
> What does nm -S say?
> I've tried to compile a sample program with gcc6 and
> __attribute__((aligned(8))) does in fact force alignment of start of
> the symbol, but size still stays 6. (and asan still barks on my test
> program).

Right, but then it means I also need to change mac_bcast[] and
mac_v6_allmcast[] in bond_alb.c to avoid false positive.

(Technically, if their alignment is 8, we have 8 bytes there,
no way it could span 2 pages)

I'll send a v2.

Re: [PATCH net] bonding: prevent out of bound accesses

[Dmitry Vyukov]

On Thu, Jun 30, 2016 at 4:08 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
> On Thu, 2016-06-30 at 15:35 +0200, Dmitry Vyukov wrote:
>
>>
>> What does nm -S say?
>> I've tried to compile a sample program with gcc6 and
>> __attribute__((aligned(8))) does in fact force alignment of start of
>> the symbol, but size still stays 6. (and asan still barks on my test
>> program).
>
> Right, but then it means I also need to change mac_bcast[] and
> mac_v6_allmcast[] in bond_alb.c to avoid false positive.
>
> (Technically, if their alignment is 8, we have 8 bytes there,
> no way it could span 2 pages)

Agree.

> I'll send a v2.

Thanks!

[PATCH v2 net] bonding: prevent out of bound accesses

[Eric Dumazet]

From: Eric Dumazet <edumazet@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

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>
---
 drivers/net/bonding/bond_3ad.c |   11 +++++++----
 drivers/net/bonding/bond_alb.c |    7 ++-----
 include/net/bonding.h          |    7 ++++++-
 3 files changed, 15 insertions(+), 10 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 + 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);
@@ -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..551f0f8dead3 100644
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c
@@ -42,13 +42,10 @@
 
 
 
-#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/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 {

Re: [PATCH v2 net] bonding: prevent out of bound accesses

[Dmitry Vyukov]

On Thu, Jun 30, 2016 at 4:13 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
> From: Eric Dumazet <edumazet@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
>
> 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>
> ---
>  drivers/net/bonding/bond_3ad.c |   11 +++++++----
>  drivers/net/bonding/bond_alb.c |    7 ++-----
>  include/net/bonding.h          |    7 ++++++-
>  3 files changed, 15 insertions(+), 10 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 + 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);
> @@ -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..551f0f8dead3 100644
> --- a/drivers/net/bonding/bond_alb.c
> +++ b/drivers/net/bonding/bond_alb.c
> @@ -42,13 +42,10 @@
>
>
>
> -#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/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 {


Acked-by: Dmitry Vyukov <dvyukov@google.com>

Re: [PATCH v2 net] bonding: prevent out of bound accesses

[Nikolay Aleksandrov]

On 30/06/16 16:13, Eric Dumazet wrote:
> From: Eric Dumazet <edumazet@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
> 
> 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>
> ---
>  drivers/net/bonding/bond_3ad.c |   11 +++++++----
>  drivers/net/bonding/bond_alb.c |    7 ++-----
>  include/net/bonding.h          |    7 ++++++-
>  3 files changed, 15 insertions(+), 10 deletions(-)
> 

+CC bonding maintainers

For v2,
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>

Re: [PATCH v2 net] bonding: prevent out of bound accesses

[Ding Tianhong]

On 2016/6/30 22:13, Eric Dumazet wrote:
> From: Eric Dumazet <edumazet@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
> 
> 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>
> ---
>  drivers/net/bonding/bond_3ad.c |   11 +++++++----
>  drivers/net/bonding/bond_alb.c |    7 ++-----
>  include/net/bonding.h          |    7 ++++++-
>  3 files changed, 15 insertions(+), 10 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 + 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);
> @@ -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..551f0f8dead3 100644
> --- a/drivers/net/bonding/bond_alb.c
> +++ b/drivers/net/bonding/bond_alb.c
> @@ -42,13 +42,10 @@
>  
>  
>  
> -#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/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 {
> 
> 
> 
> .
It is fine to me.

Acked-by: Ding Tianhong <dingtianhong@huawei.com>
> 

Re: [PATCH v2 net] bonding: prevent out of bound accesses

[David Miller]

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Thu, 30 Jun 2016 16:13:41 +0200

> From: Eric Dumazet <edumazet@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
> 
> 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>

Applied, thanks Eric.