linux.git/net/tipc, branch v4.19-rc4

tipc: check return value of __tipc_dump_start()

2018-09-12T20:15:04+00:00

When __tipc_dump_start() fails with running out of memory,
we have no reason to continue, especially we should avoid
calling tipc_dump_done().

Fixes: 8f5c5fcf3533 ("tipc: call start and done ops directly in __tipc_nl_compat_dumpit()")
Reported-and-tested-by: syzbot+3f8324abccfbf8c74a9f@syzkaller.appspotmail.com
Cc: Jon Maloy 
Cc: Ying Xue 
Signed-off-by: Cong Wang 
Acked-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: call start and done ops directly in __tipc_nl_compat_dumpit()

2018-09-07T04:49:18+00:00

__tipc_nl_compat_dumpit() uses a netlink_callback on stack,
so the only way to align it with other ->dumpit() call path
is calling tipc_dump_start() and tipc_dump_done() directly
inside it. Otherwise ->dumpit() would always get NULL from
cb->args[].

But tipc_dump_start() uses sock_net(cb->skb->sk) to retrieve
net pointer, the cb->skb here doesn't set skb->sk, the net pointer
is saved in msg->net instead, so introduce a helper function
__tipc_dump_start() to pass in msg->net.

Ying pointed out cb->args[0...3] are already used by other
callbacks on this call path, so we can't use cb->args[0] any
more, use cb->args[4] instead.

Fixes: 9a07efa9aea2 ("tipc: switch to rhashtable iterator")
Reported-and-tested-by: syzbot+e93a2c41f91b8e2c7d9b@syzkaller.appspotmail.com
Cc: Jon Maloy 
Cc: Ying Xue 
Signed-off-by: Cong Wang 
Acked-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: orphan sock in tipc_release()

2018-09-06T05:14:00+00:00

Before we unlock the sock in tipc_release(), we have to
detach sk->sk_socket from sk, otherwise a parallel
tipc_sk_fill_sock_diag() could stil read it after we
free this socket.

Fixes: c30b70deb5f4 ("tipc: implement socket diagnostics for AF_TIPC")
Reported-and-tested-by: syzbot+48804b87c16588ad491d@syzkaller.appspotmail.com
Cc: Jon Maloy 
Cc: Ying Xue 
Signed-off-by: Cong Wang 
Acked-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: correct spelling errors for tipc_topsrv_queue_evt() comments

2018-09-04T05:03:07+00:00

tipc_conn_queue_evt -> tipc_topsrv_queue_evt
tipc_send_work -> tipc_conn_send_work
tipc_send_to_sock -> tipc_conn_send_to_sock

Signed-off-by: Zhenbo Gao 
Reviewed-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: correct spelling errors for struct tipc_bc_base's comment

2018-09-04T05:03:07+00:00

Trivial fix for two spelling mistakes.

Signed-off-by: Zhenbo Gao 
Reviewed-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: switch to rhashtable iterator

2018-08-30T01:04:54+00:00

syzbot reported a use-after-free in tipc_group_fill_sock_diag(),
where tipc_group_fill_sock_diag() still reads tsk->group meanwhile
tipc_group_delete() just deletes it in tipc_release().

tipc_nl_sk_walk() aims to lock this sock when walking each sock
in the hash table to close race conditions with sock changes like
this one, by acquiring tsk->sk.sk_lock.slock spinlock, unfortunately
this doesn't work at all. All non-BH call path should take
lock_sock() instead to make it work.

tipc_nl_sk_walk() brutally iterates with raw rht_for_each_entry_rcu()
where RCU read lock is required, this is the reason why lock_sock()
can't be taken on this path. This could be resolved by switching to
rhashtable iterator API's, where taking a sleepable lock is possible.
Also, the iterator API's are friendly for restartable calls like
diag dump, the last position is remembered behind the scence,
all we need to do here is saving the iterator into cb->args[].

I tested this with parallel tipc diag dump and thousands of tipc
socket creation and release, no crash or memory leak.

Reported-by: syzbot+b9c8f3ab2994b7cd1625@syzkaller.appspotmail.com
Cc: Jon Maloy 
Cc: Ying Xue 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller

tipc: fix a missing rhashtable_walk_exit()

2018-08-30T00:52:58+00:00

rhashtable_walk_exit() must be paired with rhashtable_walk_enter().

Fixes: 40f9f4397060 ("tipc: Fix tipc_sk_reinit race conditions")
Cc: Herbert Xu 
Cc: Ying Xue 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller

tipc: fix the big/little endian issue in tipc_dest

2018-08-27T22:23:31+00:00

In function tipc_dest_push, the 32bit variables 'node' and 'port'
are stored separately in uppper and lower part of 64bit 'value'.
Then this value is assigned to dst->value which is a union like:
union
{
  struct {
    u32 port;
    u32 node;
  };
  u64 value;
}
This works on little-endian machines like x86 but fails on big-endian
machines.

The fix remove the 'value' stack parameter and even the 'value'
member of the union in tipc_dest, assign the 'node' and 'port' member
directly with the input parameter to avoid the endian issue.

Fixes: a80ae5306a73 ("tipc: improve destination linked list")
Signed-off-by: Zhenbo Gao 
Acked-by: Jon Maloy 
Signed-off-by: Haiqing Bai 
Signed-off-by: David S. Miller

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

2018-08-09T18:52:36+00:00

Overlapping changes in RXRPC, changing to ktime_get_seconds() whilst
adding some tracepoints.

Signed-off-by: David S. Miller

tipc: fix an interrupt unsafe locking scenario

2018-08-07T20:15:35+00:00

Commit 9faa89d4ed9d ("tipc: make function tipc_net_finalize() thread
safe") tries to make it thread safe to set node address, so it uses
node_list_lock lock to serialize the whole process of setting node
address in tipc_net_finalize(). But it causes the following interrupt
unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rht_deferred_worker()
  rhashtable_rehash_table()
  lock(&(&ht->lock)->rlock)
			       tipc_nl_compat_doit()
                               tipc_net_finalize()
                               local_irq_disable();
                               lock(&(&tn->node_list_lock)->rlock);
                               tipc_sk_reinit()
                               rhashtable_walk_enter()
                               lock(&(&ht->lock)->rlock);
  
  tipc_disc_rcv()
  tipc_node_check_dest()
  tipc_node_create()
  lock(&(&tn->node_list_lock)->rlock);

 *** DEADLOCK ***

When rhashtable_rehash_table() holds ht->lock on CPU0, it doesn't
disable BH. So if an interrupt happens after the lock, it can create
an inverse lock ordering between ht->lock and tn->node_list_lock. As
a consequence, deadlock might happen.

The reason causing the inverse lock ordering scenario above is because
the initial purpose of node_list_lock is not designed to do the
serialization of node address setting.

As cmpxchg() can guarantee CAS (compare-and-swap) process is atomic,
we use it to replace node_list_lock to ensure setting node address can
be atomically finished. It turns out the potential deadlock can be
avoided as well.

Fixes: 9faa89d4ed9d ("tipc: make function tipc_net_finalize() thread safe")
Signed-off-by: Ying Xue 
Acked-by: Jon Maloy 
Signed-off-by: David S. Miller