linux-stable.git/drivers/net/team, branch linux-3.17.y

team: avoid race condition in scheduling delayed work

2014-10-15T10:29:23+00:00

[ Upstream commit 47549650abd13d873fd2e5fc218db19e21031074 ]

When team_notify_peers and team_mcast_rejoin are called, they both reset
their respective .count_pending atomic variable. Then when the actual
worker function is executed, the variable is atomically decremented.
This pattern introduces a potential race condition where the
.count_pending rolls over and the worker function keeps rescheduling
until .count_pending decrements to zero again:

THREAD 1                           THREAD 2

========                           ========
team_notify_peers(teamX)
  atomic_set count_pending = 1
  schedule_delayed_work
                                   team_notify_peers(teamX)
                                   atomic_set count_pending = 1
team_notify_peers_work
  atomic_dec_and_test
    count_pending = 0
  (return)
                                   schedule_delayed_work
                                   team_notify_peers_work
                                   atomic_dec_and_test
                                     count_pending = -1
                                   schedule_delayed_work
                                   (repeat until count_pending = 0)

Instead of assigning a new value to .count_pending, use atomic_add to
tack-on the additional desired worker function invocations.

Signed-off-by: Joe Lawrence 
Acked-by: Jiri Pirko 
Fixes: fc423ff00df3a19554414ee ("team: add peer notification")
Fixes: 492b200efdd20b8fcfdac87 ("team: add support for sending multicast rejoins")
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

team: Simplify return path of team_newlink

2014-08-05T23:37:51+00:00

The variable "err" is not necessary.
Return register_netdevice() directly.

Signed-off-by: Toshiaki Makita 
Acked-by: Jiri Pirko 
Signed-off-by: David S. Miller

net: filter: split 'struct sk_filter' into socket and bpf parts

2014-08-02T22:03:58+00:00

clean up names related to socket filtering and bpf in the following way:
- everything that deals with sockets keeps 'sk_*' prefix
- everything that is pure BPF is changed to 'bpf_*' prefix

split 'struct sk_filter' into
struct sk_filter {
	atomic_t        refcnt;
	struct rcu_head rcu;
	struct bpf_prog *prog;
};
and
struct bpf_prog {
        u32                     jited:1,
                                len:31;
        struct sock_fprog_kern  *orig_prog;
        unsigned int            (*bpf_func)(const struct sk_buff *skb,
                                            const struct bpf_insn *filter);
        union {
                struct sock_filter      insns[0];
                struct bpf_insn         insnsi[0];
                struct work_struct      work;
        };
};
so that 'struct bpf_prog' can be used independent of sockets and cleans up
'unattached' bpf use cases

split SK_RUN_FILTER macro into:
    SK_RUN_FILTER to be used with 'struct sk_filter *' and
    BPF_PROG_RUN to be used with 'struct bpf_prog *'

__sk_filter_release(struct sk_filter *) gains
__bpf_prog_release(struct bpf_prog *) helper function

also perform related renames for the functions that work
with 'struct bpf_prog *', since they're on the same lines:

sk_filter_size -> bpf_prog_size
sk_filter_select_runtime -> bpf_prog_select_runtime
sk_filter_free -> bpf_prog_free
sk_unattached_filter_create -> bpf_prog_create
sk_unattached_filter_destroy -> bpf_prog_destroy
sk_store_orig_filter -> bpf_prog_store_orig_filter
sk_release_orig_filter -> bpf_release_orig_filter
__sk_migrate_filter -> bpf_migrate_filter
__sk_prepare_filter -> bpf_prepare_filter

API for attaching classic BPF to a socket stays the same:
sk_attach_filter(prog, struct sock *)/sk_detach_filter(struct sock *)
and SK_RUN_FILTER(struct sk_filter *, ctx) to execute a program
which is used by sockets, tun, af_packet

API for 'unattached' BPF programs becomes:
bpf_prog_create(struct bpf_prog **)/bpf_prog_destroy(struct bpf_prog *)
and BPF_PROG_RUN(struct bpf_prog *, ctx) to execute a program
which is used by isdn, ppp, team, seccomp, ptp, xt_bpf, cls_bpf, test_bpf

Signed-off-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

team: fix releasing uninitialized pointer to BPF prog

2014-07-31T20:10:02+00:00

Commit 34c5bd66e5ed introduced the possibility that an
uninitialized pointer on the stack (orig_fp) can call into
sk_unattached_filter_destroy() when its value is non NULL.

Before that commit orig_fp was only destroyed in the same
block where it was assigned a valid BPF prog before. Fix it
up by initializing it to NULL.

Fixes: 34c5bd66e5ed ("net: filter: don't release unattached filter through call_rcu()")
Signed-off-by: Daniel Borkmann 
Cc: Pablo Neira 
Cc: Alexei Starovoitov 
Cc: Jiri Pirko 
Signed-off-by: David S. Miller

net: filter: don't release unattached filter through call_rcu()

2014-07-31T02:56:27+00:00

sk_unattached_filter_destroy() does not always need to release the
filter object via rcu. Since this filter is never attached to the
socket, the caller should be responsible for releasing the filter
in a safe way, which may not necessarily imply rcu.

This is a short summary of clients of this function:

1) xt_bpf.c and cls_bpf.c use the bpf matchers from rules, these rules
   are removed from the packet path before the filter is released. Thus,
   the framework makes sure the filter is safely removed.

2) In the ppp driver, the ppp_lock ensures serialization between the
   xmit and filter attachment/detachment path. This doesn't use rcu
   so deferred release via rcu makes no sense.

3) In the isdn/ppp driver, it is called from isdn_ppp_release()
   the isdn_ppp_ioctl(). This driver uses mutex and spinlocks, no rcu.
   Thus, deferred rcu makes no sense to me either, the deferred releases
   may be just masking the effects of wrong locking strategy, which
   should be fixed in the driver itself.

4) In the team driver, this is the only place where the rcu
   synchronization with unattached filter is used. Therefore, this
   patch introduces synchronize_rcu() which is called from the
   genetlink path to make sure the filter doesn't go away while packets
   are still walking over it. I think we can revisit this once struct
   bpf_prog (that only wraps specific bpf code bits) is in place, then
   add some specific struct rcu_head in the scope of the team driver if
   Jiri thinks this is needed.

Deferred rcu release for unattached filters was originally introduced
in 302d663 ("filter: Allow to create sk-unattached filters").

Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: David S. Miller

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

2014-06-04T06:32:12+00:00

Conflicts:
	include/net/inetpeer.h
	net/ipv6/output_core.c

Changes in net were fixing bugs in code removed in net-next.

Signed-off-by: David S. Miller

team: fix mtu setting

2014-06-02T21:56:01+00:00

Now it is not possible to set mtu to team device which has a port
enslaved to it. The reason is that when team_change_mtu() calls
dev_set_mtu() for port device, notificator for NETDEV_PRECHANGEMTU
event is called and team_device_event() returns NOTIFY_BAD forbidding
the change. So fix this by returning NOTIFY_DONE here in case team is
changing mtu in team_change_mtu().

Introduced-by: 3d249d4c "net: introduce ethernet teaming device"
Signed-off-by: Jiri Pirko 
Acked-by: Flavio Leitner 
Signed-off-by: David S. Miller

team: lb: use sizeof(*fprog) in __fprog_create

2014-05-24T21:06:38+00:00

sock_fprog and sock_fprog_kern are of equal size, however
it's cleaner to just use sizeof(*fprog) instead to always
have correct type.

Reported-by: Dan Carpenter 
Signed-off-by: Daniel Borkmann 
Signed-off-by: David S. Miller

net: filter: let unattached filters use sock_fprog_kern

2014-05-23T20:48:05+00:00

The sk_unattached_filter_create() API is used by BPF filters that
are not directly attached or related to sockets, and are used in
team, ptp, xt_bpf, cls_bpf, etc. As such all users do their own
internal managment of obtaining filter blocks and thus already
have them in kernel memory and set up before calling into
sk_unattached_filter_create(). As a result, due to __user annotation
in sock_fprog, sparse triggers false positives (incorrect type in
assignment [different address space]) when filters are set up before
passing them to sk_unattached_filter_create(). Therefore, let
sk_unattached_filter_create() API use sock_fprog_kern to overcome
this issue.

Signed-off-by: Daniel Borkmann 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

teaming: fix vlan_features computing

2014-05-22T19:07:23+00:00

__team_compute_features() uses netdev_increment_features() to
combine vlan_features of slaves into vlan_features of the team.
As netdev_increment_features() only adds most features and we
start with TEAM_VLAN_FEATURES, we can end up with features none
of the slaves provided.

Initialize vlan_features only with the flags which are both in
TEAM_VLAN_FEATURES and NETIF_F_ALL_FOR_ALL. Right now there is
no such feature so that we actually initialize vlan_features
with zero but stating it explicitely will make the code more
future proof.

Signed-off-by: Michal Kubecek 
Signed-off-by: David S. Miller