linux.git/net/decnet, branch v4.13

net, decnet: convert dn_fib_info.fib_clntref from atomic_t to refcount_t

2017-07-04T21:35:15+00:00

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova 
Signed-off-by: Hans Liljestrand 
Signed-off-by: Kees Cook 
Signed-off-by: David Windsor 
Signed-off-by: David S. Miller

net: convert neighbour.refcnt from atomic_t to refcount_t

2017-07-01T14:39:07+00:00

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova 
Signed-off-by: Hans Liljestrand 
Signed-off-by: Kees Cook 
Signed-off-by: David Windsor 
Signed-off-by: David S. Miller

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

2017-06-21T21:35:22+00:00

Two entries being added at the same time to the IFLA
policy table, whilst parallel bug fixes to decnet
routing dst handling overlapping with the dst gc removal
in net-next.

Signed-off-by: David S. Miller

net: remove DST_NOGC flag

2017-06-18T02:54:01+00:00

Now that all the components have been changed to release dst based on
refcnt only and not depend on dst gc anymore, we can remove the
temporary flag DST_NOGC.

Note that we also need to remove the DST_NOCACHE check in dst_release()
and dst_hold_safe() because now all the dst are released based on refcnt
and behaves as DST_NOCACHE.

Signed-off-by: Wei Wang 
Acked-by: Martin KaFai Lau 
Signed-off-by: David S. Miller

decnet: take dst->__refcnt when struct dn_route is created

2017-06-18T02:54:01+00:00

struct dn_route is inserted into dn_rt_hash_table but no dst->__refcnt
is taken.
This patch makes sure the dn_rt_hash_table's reference to the dst is ref
counted.

As the dst is always ref counted properly, we can safely mark
DST_NOGC flag so dst_release() will release dst based on refcnt only.
And dst gc is no longer needed and all dst_free() or its related
function calls should be replaced with dst_release() or
dst_release_immediate(). And dst_dev_put() is called when removing dst
from the hash table to release the reference on dst->dev before we lose
pointer to it.

Also, correct the logic in dn_dst_check_expire() and dn_dst_gc() to
check dst->__refcnt to be > 1 to indicate it is referenced by other
users.

Signed-off-by: Wei Wang 
Acked-by: Martin KaFai Lau 
Signed-off-by: David S. Miller

decnet: always not take dst->__refcnt when inserting dst into hash table

2017-06-16T19:00:00+00:00

In the existing dn_route.c code, dn_route_output_slow() takes
dst->__refcnt before calling dn_insert_route() while dn_route_input_slow()
does not take dst->__refcnt before calling dn_insert_route().
This makes the whole routing code very buggy.
In dn_dst_check_expire(), dnrt_free() is called when rt expires. This
makes the routes inserted by dn_route_output_slow() not able to be
freed as the refcnt is not released.
In dn_dst_gc(), dnrt_drop() is called to release rt which could
potentially cause the dst->__refcnt to be dropped to -1.
In dn_run_flush(), dst_free() is called to release all the dst. Again,
it makes the dst inserted by dn_route_output_slow() not able to be
released and also, it does not wait on the rcu and could potentially
cause crash in the path where other users still refer to this dst.

This patch makes sure both input and output path do not take
dst->__refcnt before calling dn_insert_route() and also makes sure
dnrt_free()/dst_free() is called when removing dst from the hash table.
The only difference between those 2 calls is that dnrt_free() waits on
the rcu while dst_free() does not.

Signed-off-by: Wei Wang 
Acked-by: Martin KaFai Lau 
Signed-off-by: David S. Miller

decnet: always not take dst->__refcnt when inserting dst into hash table

2017-06-16T18:59:36+00:00

In the existing dn_route.c code, dn_route_output_slow() takes
dst->__refcnt before calling dn_insert_route() while dn_route_input_slow()
does not take dst->__refcnt before calling dn_insert_route().
This makes the whole routing code very buggy.
In dn_dst_check_expire(), dnrt_free() is called when rt expires. This
makes the routes inserted by dn_route_output_slow() not able to be
freed as the refcnt is not released.
In dn_dst_gc(), dnrt_drop() is called to release rt which could
potentially cause the dst->__refcnt to be dropped to -1.
In dn_run_flush(), dst_free() is called to release all the dst. Again,
it makes the dst inserted by dn_route_output_slow() not able to be
released and also, it does not wait on the rcu and could potentially
cause crash in the path where other users still refer to this dst.

This patch makes sure both input and output path do not take
dst->__refcnt before calling dn_insert_route() and also makes sure
dnrt_free()/dst_free() is called when removing dst from the hash table.
The only difference between those 2 calls is that dnrt_free() waits on
the rcu while dst_free() does not.

Signed-off-by: Wei Wang 
Acked-by: Martin KaFai Lau 
Signed-off-by: David S. Miller

networking: add and use skb_put_u8()

2017-06-16T15:48:40+00:00

Joe and Bjørn suggested that it'd be nicer to not have the
cast in the fairly common case of doing
	*(u8 *)skb_put(skb, 1) = c;

Add skb_put_u8() for this case, and use it across the code,
using the following spatch:

    @@
    expression SKB, C, S;
    typedef u8;
    identifier fn = {skb_put};
    fresh identifier fn2 = fn ## "_u8";
    @@
    - *(u8 *)fn(SKB, S) = C;
    + fn2(SKB, C);

Note that due to the "S", the spatch isn't perfect, it should
have checked that S is 1, but there's also places that use a
sizeof expression like sizeof(var) or sizeof(u8) etc. Turns
out that nobody ever did something like
	*(u8 *)skb_put(skb, 2) = c;

which would be wrong anyway since the second byte wouldn't be
initialized.

Suggested-by: Joe Perches 
Suggested-by: Bjørn Mork 
Signed-off-by: Johannes Berg 
Signed-off-by: David S. Miller

networking: make skb_push & __skb_push return void pointers

2017-06-16T15:48:40+00:00

It seems like a historic accident that these return unsigned char *,
and in many places that means casts are required, more often than not.

Make these functions return void * and remove all the casts across
the tree, adding a (u8 *) cast only where the unsigned char pointer
was used directly, all done with the following spatch:

    @@
    expression SKB, LEN;
    typedef u8;
    identifier fn = { skb_push, __skb_push, skb_push_rcsum };
    @@
    - *(fn(SKB, LEN))
    + *(u8 *)fn(SKB, LEN)

    @@
    expression E, SKB, LEN;
    identifier fn = { skb_push, __skb_push, skb_push_rcsum };
    type T;
    @@
    - E = ((T *)(fn(SKB, LEN)))
    + E = fn(SKB, LEN)

    @@
    expression SKB, LEN;
    identifier fn = { skb_push, __skb_push, skb_push_rcsum };
    @@
    - fn(SKB, LEN)[0]
    + *(u8 *)fn(SKB, LEN)

Note that the last part there converts from push(...)[0] to the
more idiomatic *(u8 *)push(...).

Signed-off-by: Johannes Berg 
Signed-off-by: David S. Miller

networking: make skb_put & friends return void pointers

2017-06-16T15:48:39+00:00

It seems like a historic accident that these return unsigned char *,
and in many places that means casts are required, more often than not.

Make these functions (skb_put, __skb_put and pskb_put) return void *
and remove all the casts across the tree, adding a (u8 *) cast only
where the unsigned char pointer was used directly, all done with the
following spatch:

    @@
    expression SKB, LEN;
    typedef u8;
    identifier fn = { skb_put, __skb_put };
    @@
    - *(fn(SKB, LEN))
    + *(u8 *)fn(SKB, LEN)

    @@
    expression E, SKB, LEN;
    identifier fn = { skb_put, __skb_put };
    type T;
    @@
    - E = ((T *)(fn(SKB, LEN)))
    + E = fn(SKB, LEN)

which actually doesn't cover pskb_put since there are only three
users overall.

A handful of stragglers were converted manually, notably a macro in
drivers/isdn/i4l/isdn_bsdcomp.c and, oddly enough, one of the many
instances in net/bluetooth/hci_sock.c. In the former file, I also
had to fix one whitespace problem spatch introduced.

Signed-off-by: Johannes Berg 
Signed-off-by: David S. Miller