linux-toradex.git/net/rxrpc/net_ns.c, branch v6.17

treewide: Switch/rename to timer_delete[_sync]()

2025-04-05T08:30:12+00:00

timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree
over and remove the historical wrapper inlines.

Conversion was done with coccinelle plus manual fixups where necessary.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Ingo Molnar

rxrpc: Create a procfile to display outstanding client conn bundles

2023-12-24T15:22:56+00:00

Create /proc/net/rxrpc/bundles to display outstanding rxrpc client
connection bundles.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Move the client conn cache management to the I/O thread

2023-01-06T09:43:33+00:00

Move the management of the client connection cache to the I/O thread rather
than managing it from the namespace as an aggregate across all the local
endpoints within the namespace.

This will allow a load of locking to be got rid of in a future patch as
only the I/O thread will be looking at the this.

The downside is that the total number of cached connections on the system
can get higher because the limit is now per-local rather than per-netns.
We can, however, keep the number of client conns in use across the entire
netfs and use that to reduce the expiration time of idle connection.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Don't hold a ref for connection workqueue

2022-12-01T13:36:40+00:00

Currently, rxrpc gives the connection's work item a ref on the connection
when it queues it - and this is called from the timer expiration function.
The problem comes when queue_work() fails (ie. the work item is already
queued): the timer routine must put the ref - but this may cause the
cleanup code to run.

This has the unfortunate effect that the cleanup code may then be run in
softirq context - which means that any spinlocks it might need to touch
have to be guarded to disable softirqs (ie. they need a "_bh" suffix).

 (1) Don't give a ref to the work item.

 (2) Simplify handling of service connections by adding a separate active
     count so that the refcount isn't also used for this.

 (3) Connection destruction for both client and service connections can
     then be cleaned up by putting rxrpc_put_connection() out of line and
     making a tidy progression through the destruction code (offloaded to a
     workqueue if put from softirq or processor function context).  The RCU
     part of the cleanup then only deals with the freeing at the end.

 (4) Make rxrpc_queue_conn() return immediately if it sees the active count
     is -1 rather then queuing the connection.

 (5) Make sure that the cleanup routine waits for the work item to
     complete.

 (6) Stash the rxrpc_net pointer in the conn struct so that the rcu free
     routine can use it, even if the local endpoint has been freed.

Unfortunately, neither the timer nor the work item can simply get around
the problem by just using refcount_inc_not_zero() as the waits would still
have to be done, and there would still be the possibility of having to put
the ref in the expiration function.

Note the connection work item is mostly going to go away with the main
event work being transferred to the I/O thread, so the wait in (6) will
become obsolete.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Add stats procfile and DATA packet stats

2022-11-08T16:42:15+00:00

Add a procfile, /proc/net/rxrpc/stats, to display some statistics about
what rxrpc has been doing.  Writing a blank line to the stats file will
clear the increment-only counters.  Allocated resource counters don't get
cleared.

Add some counters to count various things about DATA packets, including the
number created, transmitted and retransmitted and the number received, the
number of ACK-requests markings and the number of jumbo packets received.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org

rxrpc: Fix locking issue

2022-05-22T20:03:01+00:00

There's a locking issue with the per-netns list of calls in rxrpc.  The
pieces of code that add and remove a call from the list use write_lock()
and the calls procfile uses read_lock() to access it.  However, the timer
callback function may trigger a removal by trying to queue a call for
processing and finding that it's already queued - at which point it has a
spare refcount that it has to do something with.  Unfortunately, if it puts
the call and this reduces the refcount to 0, the call will be removed from
the list.  Unfortunately, since the _bh variants of the locking functions
aren't used, this can deadlock.

================================
WARNING: inconsistent lock state
5.18.0-rc3-build4+ #10 Not tainted
--------------------------------
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
ksoftirqd/2/25 [HC0[0]:SC1[1]:HE1:SE0] takes:
ffff888107ac4038 (&rxnet->call_lock){+.?.}-{2:2}, at: rxrpc_put_call+0x103/0x14b
{SOFTIRQ-ON-W} state was registered at:
...
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&rxnet->call_lock);
  
    lock(&rxnet->call_lock);

 *** DEADLOCK ***

1 lock held by ksoftirqd/2/25:
 #0: ffff8881008ffdb0 ((&call->timer)){+.-.}-{0:0}, at: call_timer_fn+0x5/0x23d

Changes
=======
ver #2)
 - Changed to using list_next_rcu() rather than rcu_dereference() directly.

Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both")
Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org
Signed-off-by: David S. Miller

rxrpc: Allow list of in-use local UDP endpoints to be viewed in /proc

2022-05-22T20:03:01+00:00

Allow the list of in-use local UDP endpoints in the current network
namespace to be viewed in /proc.

To aid with this, the endpoint list is converted to an hlist and RCU-safe
manipulation is used so that the list can be read with only the RCU
read lock held.

Signed-off-by: David Howells 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org
Signed-off-by: David S. Miller

rxrpc: Restore removed timer deletion

2022-04-15T09:54:49+00:00

A recent patch[1] from Eric Dumazet flipped the order in which the
keepalive timer and the keepalive worker were cancelled in order to fix a
syzbot reported issue[2].  Unfortunately, this enables the mirror image bug
whereby the timer races with rxrpc_exit_net(), restarting the worker after
it has been cancelled:

	CPU 1		CPU 2
	===============	=====================
			if (rxnet->live)
			
	rxnet->live = false;
 	cancel_work_sync(&rxnet->peer_keepalive_work);
			rxrpc_queue_work(&rxnet->peer_keepalive_work);
	del_timer_sync(&rxnet->peer_keepalive_timer);

Fix this by restoring the removed del_timer_sync() so that we try to remove
the timer twice.  If the timer runs again, it should see ->live == false
and not restart the worker.

Fixes: 1946014ca3b1 ("rxrpc: fix a race in rxrpc_exit_net()")
Signed-off-by: David Howells 
cc: Eric Dumazet 
cc: Marc Dionne 
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/20220404183439.3537837-1-eric.dumazet@gmail.com/ [1]
Link: https://syzkaller.appspot.com/bug?extid=724378c4bb58f703b09a [2]
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller

rxrpc: fix a race in rxrpc_exit_net()

2022-04-06T12:48:51+00:00

Current code can lead to the following race:

CPU0                                                 CPU1

rxrpc_exit_net()
                                                     rxrpc_peer_keepalive_worker()
                                                       if (rxnet->live)

  rxnet->live = false;
  del_timer_sync(&rxnet->peer_keepalive_timer);

                                                             timer_reduce(&rxnet->peer_keepalive_timer, jiffies + delay);

  cancel_work_sync(&rxnet->peer_keepalive_work);

rxrpc_exit_net() exits while peer_keepalive_timer is still armed,
leading to use-after-free.

syzbot report was:

ODEBUG: free active (active state 0) object type: timer_list hint: rxrpc_peer_keepalive_timeout+0x0/0xb0
WARNING: CPU: 0 PID: 3660 at lib/debugobjects.c:505 debug_print_object+0x16e/0x250 lib/debugobjects.c:505
Modules linked in:
CPU: 0 PID: 3660 Comm: kworker/u4:6 Not tainted 5.17.0-syzkaller-13993-g88e6c0207623 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
RIP: 0010:debug_print_object+0x16e/0x250 lib/debugobjects.c:505
Code: ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 af 00 00 00 48 8b 14 dd 00 1c 26 8a 4c 89 ee 48 c7 c7 00 10 26 8a e8 b1 e7 28 05 <0f> 0b 83 05 15 eb c5 09 01 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e c3
RSP: 0018:ffffc9000353fb00 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000
RDX: ffff888029196140 RSI: ffffffff815efad8 RDI: fffff520006a7f52
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815ea4ae R11: 0000000000000000 R12: ffffffff89ce23e0
R13: ffffffff8a2614e0 R14: ffffffff816628c0 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe1f2908924 CR3: 0000000043720000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 
 __debug_check_no_obj_freed lib/debugobjects.c:992 [inline]
 debug_check_no_obj_freed+0x301/0x420 lib/debugobjects.c:1023
 kfree+0xd6/0x310 mm/slab.c:3809
 ops_free_list.part.0+0x119/0x370 net/core/net_namespace.c:176
 ops_free_list net/core/net_namespace.c:174 [inline]
 cleanup_net+0x591/0xb00 net/core/net_namespace.c:598
 process_one_work+0x996/0x1610 kernel/workqueue.c:2289
 worker_thread+0x665/0x1080 kernel/workqueue.c:2436
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 

Fixes: ace45bec6d77 ("rxrpc: Fix firewall route keepalive")
Signed-off-by: Eric Dumazet 
Cc: David Howells 
Cc: Marc Dionne 
Cc: linux-afs@lists.infradead.org
Reported-by: syzbot 
Signed-off-by: David S. Miller

rxrpc: Rewrite the client connection manager

2020-09-08T20:11:43+00:00

Rewrite the rxrpc client connection manager so that it can support multiple
connections for a given security key to a peer.  The following changes are
made:

 (1) For each open socket, the code currently maintains an rbtree with the
     connections placed into it, keyed by communications parameters.  This
     is tricky to maintain as connections can be culled from the tree or
     replaced within it.  Connections can require replacement for a number
     of reasons, e.g. their IDs span too great a range for the IDR data
     type to represent efficiently, the call ID numbers on that conn would
     overflow or the conn got aborted.

     This is changed so that there's now a connection bundle object placed
     in the tree, keyed on the same parameters.  The bundle, however, does
     not need to be replaced.

 (2) An rxrpc_bundle object can now manage the available channels for a set
     of parallel connections.  The lock that manages this is moved there
     from the rxrpc_connection struct (channel_lock).

 (3) There'a a dummy bundle for all incoming connections to share so that
     they have a channel_lock too.  It might be better to give each
     incoming connection its own bundle.  This bundle is not needed to
     manage which channels incoming calls are made on because that's the
     solely at whim of the client.

 (4) The restrictions on how many client connections are around are
     removed.  Instead, a previous patch limits the number of client calls
     that can be allocated.  Ordinarily, client connections are reaped
     after 2 minutes on the idle queue, but when more than a certain number
     of connections are in existence, the reaper starts reaping them after
     2s of idleness instead to get the numbers back down.

     It could also be made such that new call allocations are forced to
     wait until the number of outstanding connections subsides.

Signed-off-by: David Howells