When a local endpoint is ceases to be in use, such as when the kafs module
is unloaded, the kernel will emit an assertion failure if there are any
outstanding client connections:
rxrpc: Assertion failed
------------[ cut here ]------------
kernel BUG at net/rxrpc/local_object.c:433!
and even beyond that, will evince other oopses if there are service
connections still present.
Fix this by:
(1) Removing the triggering of connection reaping when an rxrpc socket is
released. These don't actually clean up the connections anyway - and
further, the local endpoint may still be in use through another
socket.
(2) Mark the local endpoint as dead when we start the process of tearing
it down.
(3) When destroying a local endpoint, strip all of its client connections
from the idle list and discard the ref on each that the list was
holding.
(4) When destroying a local endpoint, call the service connection reaper
directly (rather than through a workqueue) to immediately kill off all
outstanding service connections.
(5) Make the service connection reaper reap connections for which the
local endpoint is marked dead.
Only after destroying the connections can we close the socket lest we get
an oops in a workqueue that's looking at a connection or a peer.
Fixes: 3d18cbb7fd0c ("rxrpc: Fix conn expiry timers")
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
rxrpc_queue_local() attempts to queue the local endpoint it is given and
then, if successful, prints a trace line. The trace line includes the
current usage count - but we're not allowed to look at the local endpoint
at this point as we passed our ref on it to the workqueue.
Fix this by reading the usage count before queuing the work item.
Also fix the reading of local->debug_id for trace lines, which must be done
with the same consideration as reading the usage count.
Fixes: 09d2bf595db4 ("rxrpc: Add a tracepoint to track rxrpc_local refcounting")
Reported-by: syzbot+78e71c5bab4f76a6a719@syzkaller.appspotmail.com
Signed-off-by: David Howells <dhowells@redhat.com>
When a local endpoint (struct rxrpc_local) ceases to be in use by any
AF_RXRPC sockets, it starts the process of being destroyed, but this
doesn't cause it to be removed from the namespace endpoint list immediately
as tearing it down isn't trivial and can't be done in softirq context, so
it gets deferred.
If a new socket comes along that wants to bind to the same endpoint, a new
rxrpc_local object will be allocated and rxrpc_lookup_local() will use
list_replace() to substitute the new one for the old.
Then, when the dying object gets to rxrpc_local_destroyer(), it is removed
unconditionally from whatever list it is on by calling list_del_init().
However, list_replace() doesn't reset the pointers in the replaced
list_head and so the list_del_init() will likely corrupt the local
endpoints list.
Fix this by using list_replace_init() instead.
Fixes: 730c5fd42c1e ("rxrpc: Fix local endpoint refcounting")
Reported-by: syzbot+193e29e9387ea5837f1d@syzkaller.appspotmail.com
Signed-off-by: David Howells <dhowells@redhat.com>
Fix rxrpc_unuse_local() to handle a NULL local pointer as it can be called
on an unbound socket on which rx->local is not yet set.
The following reproduced (includes omitted):
int main(void)
{
socket(AF_RXRPC, SOCK_DGRAM, AF_INET);
return 0;
}
causes the following oops to occur:
BUG: kernel NULL pointer dereference, address: 0000000000000010
...
RIP: 0010:rxrpc_unuse_local+0x8/0x1b
...
Call Trace:
rxrpc_release+0x2b5/0x338
__sock_release+0x37/0xa1
sock_close+0x14/0x17
__fput+0x115/0x1e9
task_work_run+0x72/0x98
do_exit+0x51b/0xa7a
? __context_tracking_exit+0x4e/0x10e
do_group_exit+0xab/0xab
__x64_sys_exit_group+0x14/0x17
do_syscall_64+0x89/0x1d4
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Reported-by: syzbot+20dee719a2e090427b5f@syzkaller.appspotmail.com
Fixes: 730c5fd42c1e ("rxrpc: Fix local endpoint refcounting")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeffrey Altman <jaltman@auristor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The object lifetime management on the rxrpc_local struct is broken in that
the rxrpc_local_processor() function is expected to clean up and remove an
object - but it may get requeued by packets coming in on the backing UDP
socket once it starts running.
This may result in the assertion in rxrpc_local_rcu() firing because the
memory has been scheduled for RCU destruction whilst still queued:
rxrpc: Assertion failed
------------[ cut here ]------------
kernel BUG at net/rxrpc/local_object.c:468!
Note that if the processor comes around before the RCU free function, it
will just do nothing because ->dead is true.
Fix this by adding a separate refcount to count active users of the
endpoint that causes the endpoint to be destroyed when it reaches 0.
The original refcount can then be used to refcount objects through the work
processor and cause the memory to be rcu freed when that reaches 0.
Fixes: 4f95dd78a77e ("rxrpc: Rework local endpoint management")
Reported-by: syzbot+1e0edc4b8b7494c28450@syzkaller.appspotmail.com
Signed-off-by: David Howells <dhowells@redhat.com>
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public licence as published by the free software foundation either version 2 of the licence or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 114 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190520170857.552531963@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Two easy cases of overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
After commit 5271953cad31 ("rxrpc: Use the UDP encap_rcv hook"),
rxrpc_input_packet() is directly called from lockless UDP receive
path, under rcu_read_lock() protection.
It must therefore use RCU rules :
- udp_sk->sk_user_data can be cleared at any point in this function.
rcu_dereference_sk_user_data() is what we need here.
- Also, since sk_user_data might have been set in rxrpc_open_socket()
we must observe a proper RCU grace period before kfree(local) in
rxrpc_lookup_local()
v4: @local can be NULL in xrpc_lookup_local() as reported by kbuild test robot <lkp@intel.com>
and Julia Lawall <julia.lawall@lip6.fr>, thanks !
v3,v2 : addressed David Howells feedback, thanks !
syzbot reported :
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 19236 Comm: syz-executor703 Not tainted 5.1.0-rc6 #79
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__lock_acquire+0xbef/0x3fb0 kernel/locking/lockdep.c:3573
Code: 00 0f 85 a5 1f 00 00 48 81 c4 10 01 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 <80> 3c 02 00 0f 85 4a 21 00 00 49 81 7d 00 20 54 9c 89 0f 84 cf f4
RSP: 0018:ffff88809d7aef58 EFLAGS: 00010002
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000026 RSI: 0000000000000000 RDI: 0000000000000001
RBP: ffff88809d7af090 R08: 0000000000000001 R09: 0000000000000001
R10: ffffed1015d05bc7 R11: ffff888089428600 R12: 0000000000000000
R13: 0000000000000130 R14: 0000000000000001 R15: 0000000000000001
FS: 00007f059044d700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004b6040 CR3: 00000000955ca000 CR4: 00000000001406f0
Call Trace:
lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:4211
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152
skb_queue_tail+0x26/0x150 net/core/skbuff.c:2972
rxrpc_reject_packet net/rxrpc/input.c:1126 [inline]
rxrpc_input_packet+0x4a0/0x5536 net/rxrpc/input.c:1414
udp_queue_rcv_one_skb+0xaf2/0x1780 net/ipv4/udp.c:2011
udp_queue_rcv_skb+0x128/0x730 net/ipv4/udp.c:2085
udp_unicast_rcv_skb.isra.0+0xb9/0x360 net/ipv4/udp.c:2245
__udp4_lib_rcv+0x701/0x2ca0 net/ipv4/udp.c:2301
udp_rcv+0x22/0x30 net/ipv4/udp.c:2482
ip_protocol_deliver_rcu+0x60/0x8f0 net/ipv4/ip_input.c:208
ip_local_deliver_finish+0x23b/0x390 net/ipv4/ip_input.c:234
NF_HOOK include/linux/netfilter.h:289 [inline]
NF_HOOK include/linux/netfilter.h:283 [inline]
ip_local_deliver+0x1e9/0x520 net/ipv4/ip_input.c:255
dst_input include/net/dst.h:450 [inline]
ip_rcv_finish+0x1e1/0x300 net/ipv4/ip_input.c:413
NF_HOOK include/linux/netfilter.h:289 [inline]
NF_HOOK include/linux/netfilter.h:283 [inline]
ip_rcv+0xe8/0x3f0 net/ipv4/ip_input.c:523
__netif_receive_skb_one_core+0x115/0x1a0 net/core/dev.c:4987
__netif_receive_skb+0x2c/0x1c0 net/core/dev.c:5099
netif_receive_skb_internal+0x117/0x660 net/core/dev.c:5202
napi_frags_finish net/core/dev.c:5769 [inline]
napi_gro_frags+0xade/0xd10 net/core/dev.c:5843
tun_get_user+0x2f24/0x3fb0 drivers/net/tun.c:1981
tun_chr_write_iter+0xbd/0x156 drivers/net/tun.c:2027
call_write_iter include/linux/fs.h:1866 [inline]
do_iter_readv_writev+0x5e1/0x8e0 fs/read_write.c:681
do_iter_write fs/read_write.c:957 [inline]
do_iter_write+0x184/0x610 fs/read_write.c:938
vfs_writev+0x1b3/0x2f0 fs/read_write.c:1002
do_writev+0x15e/0x370 fs/read_write.c:1037
__do_sys_writev fs/read_write.c:1110 [inline]
__se_sys_writev fs/read_write.c:1107 [inline]
__x64_sys_writev+0x75/0xb0 fs/read_write.c:1107
do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Fixes: 5271953cad31 ("rxrpc: Use the UDP encap_rcv hook")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.
This patch fixes the following warning:
net/rxrpc/local_object.c: In function ‘rxrpc_open_socket’:
net/rxrpc/local_object.c:175:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (ret < 0) {
^
net/rxrpc/local_object.c:184:2: note: here
case AF_INET:
^~~~
Warning level 3 was used: -Wimplicit-fallthrough=3
Currently, GCC is expecting to find the fall-through annotations
at the very bottom of the case and on its own line. That's why
I had to add the annotation, although the intentional fall-through
is already mentioned in a few lines above.
This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
SO_TIMESTAMP, SO_TIMESTAMPNS and SO_TIMESTAMPING options, the way they are currently defined, are not y2038 safe. Subsequent patches in the series add new y2038 safe versions of these options which provide 64 bit timestamps on all architectures uniformly. Hence, rename existing options with OLD tag suffixes. Also note that kernel will not use the untagged SO_TIMESTAMP* and SCM_TIMESTAMP* options internally anymore. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Acked-by: Willem de Bruijn <willemb@google.com> Cc: deller@gmx.de Cc: dhowells@redhat.com Cc: jejb@parisc-linux.org Cc: ralf@linux-mips.org Cc: rth@twiddle.net Cc: linux-afs@lists.infradead.org Cc: linux-alpha@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linux-parisc@vger.kernel.org Cc: linux-rdma@vger.kernel.org Cc: sparclinux@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>