| Message ID | 20160630085950.61e5c7e0@gandalf.local.home (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
> On Jun 30, 2016, at 08:59, Steven Rostedt <rostedt@goodmis.org> wrote: > > [ resending as a new email, as I'm assuming people do not sort their > INBOX via last email on thread, thus my last email is sitting in the > bottom of everyone's INBOX ] > > I've hit this again. Not sure when it started, but I applied my old > debug trace_printk() patch (attached) and rebooted (4.5.7). I just > tested the latest kernel from Linus's tree (from last nights pull), and > it still gives me the problem. > > Here's the trace I have: > > kworker/3:1H-134 [003] ..s. 61.036129: inet_csk_get_port: snum 805 > kworker/3:1H-134 [003] ..s. 61.036135: <stack trace> > => sched_clock > => inet_addr_type_table > => security_capable > => inet_bind > => xs_bind > => release_sock > => sock_setsockopt > => __sock_create > => xs_create_sock.isra.19 > => xs_tcp_setup_socket > => process_one_work > => worker_thread > => worker_thread > => kthread > => ret_from_fork > => kthread > kworker/3:1H-134 [003] ..s. 61.036136: inet_bind_hash: add 805 > kworker/3:1H-134 [003] ..s. 61.036138: <stack trace> > => inet_csk_get_port > => sched_clock > => inet_addr_type_table > => security_capable > => inet_bind > => xs_bind > => release_sock > => sock_setsockopt > => __sock_create > => xs_create_sock.isra.19 > => xs_tcp_setup_socket > => process_one_work > => worker_thread > => worker_thread > => kthread > => ret_from_fork > => kthread > kworker/3:1H-134 [003] .... 61.036139: xs_bind: RPC: xs_bind 4.136.255.255:805: ok (0) > kworker/3:1H-134 [003] .... 61.036140: xs_tcp_setup_socket: RPC: worker connecting xprt ffff880407eca800 via tcp to 192.168.23.22 (port 43651) > kworker/3:1H-134 [003] .... 61.036162: xs_tcp_setup_socket: RPC: ffff880407eca800 connect status 115 connected 0 sock state 2 > <idle>-0 [001] ..s. 61.036450: xs_tcp_state_change: RPC: xs_tcp_state_change client ffff880407eca800... > <idle>-0 [001] ..s. 61.036452: xs_tcp_state_change: RPC: state 1 conn 0 dead 0 zapped 1 sk_shutdown 0 > kworker/1:1H-136 [001] .... 61.036476: xprt_connect_status: RPC: 43 xprt_connect_status: retrying > kworker/1:1H-136 [001] .... 61.036478: xprt_prepare_transmit: RPC: 43 xprt_prepare_transmit > kworker/1:1H-136 [001] .... 61.036479: xprt_transmit: RPC: 43 xprt_transmit(72) > kworker/1:1H-136 [001] .... 61.036486: xs_tcp_send_request: RPC: xs_tcp_send_request(72) = 0 > kworker/1:1H-136 [001] .... 61.036487: xprt_transmit: RPC: 43 xmit complete > <idle>-0 [001] ..s. 61.036789: xs_tcp_data_ready: RPC: xs_tcp_data_ready... > kworker/1:1H-136 [001] .... 61.036798: xs_tcp_data_recv: RPC: xs_tcp_data_recv started > kworker/1:1H-136 [001] .... 61.036799: xs_tcp_data_recv: RPC: reading TCP record fragment of length 24 > kworker/1:1H-136 [001] .... 61.036799: xs_tcp_data_recv: RPC: reading XID (4 bytes) > kworker/1:1H-136 [001] .... 61.036800: xs_tcp_data_recv: RPC: reading request with XID 2f4c3f88 > kworker/1:1H-136 [001] .... 61.036800: xs_tcp_data_recv: RPC: reading CALL/REPLY flag (4 bytes) > kworker/1:1H-136 [001] .... 61.036801: xs_tcp_data_recv: RPC: read reply XID 2f4c3f88 > kworker/1:1H-136 [001] ..s. 61.036801: xs_tcp_data_recv: RPC: XID 2f4c3f88 read 16 bytes > kworker/1:1H-136 [001] ..s. 61.036802: xs_tcp_data_recv: RPC: xprt = ffff880407eca800, tcp_copied = 24, tcp_offset = 24, tcp_reclen = 24 > kworker/1:1H-136 [001] ..s. 61.036802: xprt_complete_rqst: RPC: 43 xid 2f4c3f88 complete (24 bytes received) > kworker/1:1H-136 [001] .... 61.036803: xs_tcp_data_recv: RPC: xs_tcp_data_recv done > kworker/1:1H-136 [001] .... 61.036812: xprt_release: RPC: 43 release request ffff88040b270800 > > > # unhide-tcp > Unhide-tcp 20130526 > Copyright © 2013 Yago Jesus & Patrick Gouin > License GPLv3+ : GNU GPL version 3 or later > http://www.unhide-forensics.info > Used options: > [*]Starting TCP checking > > Found Hidden port that not appears in ss: 805 > What is a “Hidden port that not appears in ss: 805”, and what does this report mean? Are we failing to close a socket? Cheers Trond -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 30 Jun 2016 13:17:47 +0000 Trond Myklebust <trondmy@primarydata.com> wrote: > > On Jun 30, 2016, at 08:59, Steven Rostedt <rostedt@goodmis.org> wrote: > > > > [ resending as a new email, as I'm assuming people do not sort their > > INBOX via last email on thread, thus my last email is sitting in the > > bottom of everyone's INBOX ] > > > > I've hit this again. Not sure when it started, but I applied my old > > debug trace_printk() patch (attached) and rebooted (4.5.7). I just > > tested the latest kernel from Linus's tree (from last nights pull), and > > it still gives me the problem. > > > > Here's the trace I have: > > > > kworker/3:1H-134 [003] ..s. 61.036129: inet_csk_get_port: snum 805 Here's were the port is taken > > kworker/3:1H-134 [003] ..s. 61.036135: <stack trace> > > => sched_clock > > => inet_addr_type_table > > => security_capable > > => inet_bind > > => xs_bind > > => release_sock > > => sock_setsockopt > > => __sock_create > > => xs_create_sock.isra.19 > > => xs_tcp_setup_socket > > => process_one_work > > => worker_thread > > => worker_thread > > => kthread > > => ret_from_fork > > => kthread > > kworker/3:1H-134 [003] ..s. 61.036136: inet_bind_hash: add 805 > > kworker/3:1H-134 [003] ..s. 61.036138: <stack trace> > > => inet_csk_get_port > > => sched_clock > > => inet_addr_type_table > > => security_capable > > => inet_bind > > => xs_bind > > => release_sock > > => sock_setsockopt > > => __sock_create > > => xs_create_sock.isra.19 > > => xs_tcp_setup_socket > > => process_one_work > > => worker_thread > > => worker_thread > > => kthread > > => ret_from_fork > > => kthread > > kworker/3:1H-134 [003] .... 61.036139: xs_bind: RPC: xs_bind 4.136.255.255:805: ok (0) Here's where it is bounded. > > kworker/3:1H-134 [003] .... 61.036140: xs_tcp_setup_socket: RPC: worker connecting xprt ffff880407eca800 via tcp to 192.168.23.22 (port 43651) > > kworker/3:1H-134 [003] .... 61.036162: xs_tcp_setup_socket: RPC: ffff880407eca800 connect status 115 connected 0 sock state 2 > > <idle>-0 [001] ..s. 61.036450: xs_tcp_state_change: RPC: xs_tcp_state_change client ffff880407eca800... > > <idle>-0 [001] ..s. 61.036452: xs_tcp_state_change: RPC: state 1 conn 0 dead 0 zapped 1 sk_shutdown 0 > > kworker/1:1H-136 [001] .... 61.036476: xprt_connect_status: RPC: 43 xprt_connect_status: retrying > > kworker/1:1H-136 [001] .... 61.036478: xprt_prepare_transmit: RPC: 43 xprt_prepare_transmit > > kworker/1:1H-136 [001] .... 61.036479: xprt_transmit: RPC: 43 xprt_transmit(72) > > kworker/1:1H-136 [001] .... 61.036486: xs_tcp_send_request: RPC: xs_tcp_send_request(72) = 0 > > kworker/1:1H-136 [001] .... 61.036487: xprt_transmit: RPC: 43 xmit complete > > <idle>-0 [001] ..s. 61.036789: xs_tcp_data_ready: RPC: xs_tcp_data_ready... > > kworker/1:1H-136 [001] .... 61.036798: xs_tcp_data_recv: RPC: xs_tcp_data_recv started > > kworker/1:1H-136 [001] .... 61.036799: xs_tcp_data_recv: RPC: reading TCP record fragment of length 24 > > kworker/1:1H-136 [001] .... 61.036799: xs_tcp_data_recv: RPC: reading XID (4 bytes) > > kworker/1:1H-136 [001] .... 61.036800: xs_tcp_data_recv: RPC: reading request with XID 2f4c3f88 > > kworker/1:1H-136 [001] .... 61.036800: xs_tcp_data_recv: RPC: reading CALL/REPLY flag (4 bytes) > > kworker/1:1H-136 [001] .... 61.036801: xs_tcp_data_recv: RPC: read reply XID 2f4c3f88 > > kworker/1:1H-136 [001] ..s. 61.036801: xs_tcp_data_recv: RPC: XID 2f4c3f88 read 16 bytes > > kworker/1:1H-136 [001] ..s. 61.036802: xs_tcp_data_recv: RPC: xprt = ffff880407eca800, tcp_copied = 24, tcp_offset = 24, tcp_reclen = 24 > > kworker/1:1H-136 [001] ..s. 61.036802: xprt_complete_rqst: RPC: 43 xid 2f4c3f88 complete (24 bytes received) > > kworker/1:1H-136 [001] .... 61.036803: xs_tcp_data_recv: RPC: xs_tcp_data_recv done > > kworker/1:1H-136 [001] .... 61.036812: xprt_release: RPC: 43 release request ffff88040b270800 > > > > > > # unhide-tcp > > Unhide-tcp 20130526 > > Copyright © 2013 Yago Jesus & Patrick Gouin > > License GPLv3+ : GNU GPL version 3 or later > > http://www.unhide-forensics.info > > Used options: > > [*]Starting TCP checking > > > > Found Hidden port that not appears in ss: 805 > > > > What is a “Hidden port that not appears in ss: 805”, and what does this report mean? Are we failing to close a socket? I believe hidden ports are ports that are bound to no socket. Basically, a "port leak". Where they are in limbo and can never be reused. I looked at my past report, and everthing is exactly like the issue before. When I first boot my box, the port is there, I have the above trace. I run netstat -tapn and grep for the port. And it shows that it is an established socket between my box and my wife's box (I have a nfs mounted file system for her to copy her pictures to my server). After a couple of minutes, the port turns from ESTABLISHED to TIME_WAIT, and after another minute it disappears. At that moment, the unhide-tcp shows the port as hidden. When the socket goes away (without releasing the port) I see this in my trace: kworker/1:1H-131 [001] ..s. 364.762537: xs_tcp_state_change: RPC: xs_tcp_state_change client ffff88040ad68800... kworker/1:1H-131 [001] ..s. 364.762539: xs_tcp_state_change: RPC: state 4 conn 1 dead 0 zapped 1 sk_shutdown 3 <idle>-0 [001] ..s. 364.762715: xs_tcp_state_change: RPC: xs_tcp_state_change client ffff88040ad68800... <idle>-0 [001] ..s. 364.762716: xs_tcp_state_change: RPC: state 5 conn 0 dead 0 zapped 1 sk_shutdown 3 <idle>-0 [001] ..s. 364.762728: xs_tcp_state_change: RPC: xs_tcp_state_change client ffff88040ad68800... <idle>-0 [001] ..s. 364.762728: xs_tcp_state_change: RPC: state 7 conn 0 dead 0 zapped 1 sk_shutdown 3 <idle>-0 [001] ..s. 364.762729: xprt_disconnect_done: RPC: disconnected transport ffff88040ad68800 <idle>-0 [001] ..s. 364.762730: xs_tcp_state_change: RPC: xs_tcp_state_change client ffff88040ad68800... <idle>-0 [001] ..s. 364.762730: xs_tcp_state_change: RPC: state 7 conn 0 dead 0 zapped 1 sk_shutdown 3 <idle>-0 [001] ..s. 364.762730: xprt_disconnect_done: RPC: disconnected transport ffff88040ad68800 I can add more trace_printk()s if it would help. -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 30 Jun 2016 11:23:41 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:
> I can add more trace_printk()s if it would help.
I added a trace_printk() in inet_bind_bucket_destroy() to print out
some information on the socket used by xs_bind(), and it shows that the
bind destroy is called, but the list is not empty.
/*
* Caller must hold hashbucket lock for this tb with local BH disabled
*/
void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket *tb)
{
if (!current->mm && xs_port == tb->port) {
trace_printk("destroy %d empty=%d %p\n",
tb->port, hlist_empty(&tb->owners), tb);
trace_dump_stack(1);
}
if (hlist_empty(&tb->owners)) {
__hlist_del(&tb->node);
kmem_cache_free(cachep, tb);
}
}
I created "xs_port" to hold the port of the variable used by xs_bind,
and when it is called, the hlist_empty(&tb->owners) returns false.
I'll add more trace_printks to find out where those owners are being
added.
-- Steve
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
> On Jun 30, 2016, at 11:23, Steven Rostedt <rostedt@goodmis.org> wrote: > > On Thu, 30 Jun 2016 13:17:47 +0000 > Trond Myklebust <trondmy@primarydata.com> wrote: > >>> On Jun 30, 2016, at 08:59, Steven Rostedt <rostedt@goodmis.org> wrote: >>> >>> [ resending as a new email, as I'm assuming people do not sort their >>> INBOX via last email on thread, thus my last email is sitting in the >>> bottom of everyone's INBOX ] >>> >>> I've hit this again. Not sure when it started, but I applied my old >>> debug trace_printk() patch (attached) and rebooted (4.5.7). I just >>> tested the latest kernel from Linus's tree (from last nights pull), and >>> it still gives me the problem. >>> >>> Here's the trace I have: >>> >>> kworker/3:1H-134 [003] ..s. 61.036129: inet_csk_get_port: snum 805 > > Here's were the port is taken > >>> kworker/3:1H-134 [003] ..s. 61.036135: <stack trace> >>> => sched_clock >>> => inet_addr_type_table >>> => security_capable >>> => inet_bind >>> => xs_bind >>> => release_sock >>> => sock_setsockopt >>> => __sock_create >>> => xs_create_sock.isra.19 >>> => xs_tcp_setup_socket >>> => process_one_work >>> => worker_thread >>> => worker_thread >>> => kthread >>> => ret_from_fork >>> => kthread >>> kworker/3:1H-134 [003] ..s. 61.036136: inet_bind_hash: add 805 >>> kworker/3:1H-134 [003] ..s. 61.036138: <stack trace> >>> => inet_csk_get_port >>> => sched_clock >>> => inet_addr_type_table >>> => security_capable >>> => inet_bind >>> => xs_bind >>> => release_sock >>> => sock_setsockopt >>> => __sock_create >>> => xs_create_sock.isra.19 >>> => xs_tcp_setup_socket >>> => process_one_work >>> => worker_thread >>> => worker_thread >>> => kthread >>> => ret_from_fork >>> => kthread >>> kworker/3:1H-134 [003] .... 61.036139: xs_bind: RPC: xs_bind 4.136.255.255:805: ok (0) > > Here's where it is bounded. > >>> kworker/3:1H-134 [003] .... 61.036140: xs_tcp_setup_socket: RPC: worker connecting xprt ffff880407eca800 via tcp to 192.168.23.22 (port 43651) >>> kworker/3:1H-134 [003] .... 61.036162: xs_tcp_setup_socket: RPC: ffff880407eca800 connect status 115 connected 0 sock state 2 >>> <idle>-0 [001] ..s. 61.036450: xs_tcp_state_change: RPC: xs_tcp_state_change client ffff880407eca800... >>> <idle>-0 [001] ..s. 61.036452: xs_tcp_state_change: RPC: state 1 conn 0 dead 0 zapped 1 sk_shutdown 0 >>> kworker/1:1H-136 [001] .... 61.036476: xprt_connect_status: RPC: 43 xprt_connect_status: retrying >>> kworker/1:1H-136 [001] .... 61.036478: xprt_prepare_transmit: RPC: 43 xprt_prepare_transmit >>> kworker/1:1H-136 [001] .... 61.036479: xprt_transmit: RPC: 43 xprt_transmit(72) >>> kworker/1:1H-136 [001] .... 61.036486: xs_tcp_send_request: RPC: xs_tcp_send_request(72) = 0 >>> kworker/1:1H-136 [001] .... 61.036487: xprt_transmit: RPC: 43 xmit complete >>> <idle>-0 [001] ..s. 61.036789: xs_tcp_data_ready: RPC: xs_tcp_data_ready... >>> kworker/1:1H-136 [001] .... 61.036798: xs_tcp_data_recv: RPC: xs_tcp_data_recv started >>> kworker/1:1H-136 [001] .... 61.036799: xs_tcp_data_recv: RPC: reading TCP record fragment of length 24 >>> kworker/1:1H-136 [001] .... 61.036799: xs_tcp_data_recv: RPC: reading XID (4 bytes) >>> kworker/1:1H-136 [001] .... 61.036800: xs_tcp_data_recv: RPC: reading request with XID 2f4c3f88 >>> kworker/1:1H-136 [001] .... 61.036800: xs_tcp_data_recv: RPC: reading CALL/REPLY flag (4 bytes) >>> kworker/1:1H-136 [001] .... 61.036801: xs_tcp_data_recv: RPC: read reply XID 2f4c3f88 >>> kworker/1:1H-136 [001] ..s. 61.036801: xs_tcp_data_recv: RPC: XID 2f4c3f88 read 16 bytes >>> kworker/1:1H-136 [001] ..s. 61.036802: xs_tcp_data_recv: RPC: xprt = ffff880407eca800, tcp_copied = 24, tcp_offset = 24, tcp_reclen = 24 >>> kworker/1:1H-136 [001] ..s. 61.036802: xprt_complete_rqst: RPC: 43 xid 2f4c3f88 complete (24 bytes received) >>> kworker/1:1H-136 [001] .... 61.036803: xs_tcp_data_recv: RPC: xs_tcp_data_recv done >>> kworker/1:1H-136 [001] .... 61.036812: xprt_release: RPC: 43 release request ffff88040b270800 >>> >>> >>> # unhide-tcp >>> Unhide-tcp 20130526 >>> Copyright © 2013 Yago Jesus & Patrick Gouin >>> License GPLv3+ : GNU GPL version 3 or later >>> http://www.unhide-forensics.info >>> Used options: >>> [*]Starting TCP checking >>> >>> Found Hidden port that not appears in ss: 805 >>> >> >> What is a “Hidden port that not appears in ss: 805”, and what does this report mean? Are we failing to close a socket? > > I believe hidden ports are ports that are bound to no socket. > Basically, a "port leak". Where they are in limbo and can never be > reused. > > I looked at my past report, and everthing is exactly like the issue > before. When I first boot my box, the port is there, I have the above > trace. I run netstat -tapn and grep for the port. And it shows that it > is an established socket between my box and my wife's box (I have a nfs > mounted file system for her to copy her pictures to my server). After a > couple of minutes, the port turns from ESTABLISHED to TIME_WAIT, and > after another minute it disappears. At that moment, the unhide-tcp > shows the port as hidden. > > When the socket goes away (without releasing the port) I see this in my > trace: > > kworker/1:1H-131 [001] ..s. 364.762537: xs_tcp_state_change: RPC: xs_tcp_state_change client ffff88040ad68800... > kworker/1:1H-131 [001] ..s. 364.762539: xs_tcp_state_change: RPC: state 4 conn 1 dead 0 zapped 1 sk_shutdown 3 > <idle>-0 [001] ..s. 364.762715: xs_tcp_state_change: RPC: xs_tcp_state_change client ffff88040ad68800... > <idle>-0 [001] ..s. 364.762716: xs_tcp_state_change: RPC: state 5 conn 0 dead 0 zapped 1 sk_shutdown 3 > <idle>-0 [001] ..s. 364.762728: xs_tcp_state_change: RPC: xs_tcp_state_change client ffff88040ad68800... > <idle>-0 [001] ..s. 364.762728: xs_tcp_state_change: RPC: state 7 conn 0 dead 0 zapped 1 sk_shutdown 3 > <idle>-0 [001] ..s. 364.762729: xprt_disconnect_done: RPC: disconnected transport ffff88040ad68800 > <idle>-0 [001] ..s. 364.762730: xs_tcp_state_change: RPC: xs_tcp_state_change client ffff88040ad68800... > <idle>-0 [001] ..s. 364.762730: xs_tcp_state_change: RPC: state 7 conn 0 dead 0 zapped 1 sk_shutdown 3 > <idle>-0 [001] ..s. 364.762730: xprt_disconnect_done: RPC: disconnected transport ffff88040ad68800 > > I can add more trace_printk()s if it would help. Wait. So the NFS mount is still active, it’s just that the socket disconnected due to no traffic? That should be OK. Granted that the port can’t be reused by another process, but you really don’t want that: what if there are no other ports available and you start writing to a file on the NFS partition? Cheers Trond
On Thu, 30 Jun 2016 18:30:42 +0000 Trond Myklebust <trondmy@primarydata.com> wrote: > Wait. So the NFS mount is still active, it’s just that the socket > disconnected due to no traffic? That should be OK. Granted that the > port can’t be reused by another process, but you really don’t want > that: what if there are no other ports available and you start > writing to a file on the NFS partition? What would cause the port to be connected to a socket again? I copied a large file to the nfs mount, and the hidden port is still there? Remember, this wasn't always the case, the hidden port is a recent issue. I ran wireshark on this and it appears to create two ports for NFS. One of them is canceled by the client (sends a FIN/ACK) and this port is what lays around never to be used again, and uses the other port for all connections after that. When I unmount the NFS directory, the port is finally freed (but has no socket attached to it). What is the purpose of keeping this port around? I can reproduce this by having the client unmount and remount the directory. -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 30 Jun 2016 16:07:26 -0400 Steven Rostedt <rostedt@goodmis.org> wrote: > I can reproduce this by having the client unmount and remount the > directory. It gets even more interesting. When I unmount the directory, the hidden port does not go away. It is still there. But if I mount it again, it goes away (until it times out again). Even more info: When I first mount it, it creates 3 sockets, where one immediately is closed: tcp 0 0 192.168.23.9:892 192.168.23.22:44672 TIME_WAIT - tcp 0 0 192.168.23.9:2049 192.168.23.22:815 ESTABLISHED - tcp 0 0 192.168.23.9:754 192.168.23.22:44672 ESTABLISHED - (192.168.23.22 is the machine remotely mounting a directory from the server 192.168.23.9) The trace of port 892 is this: kworker/u32:1-13473 [000] .... 4093.915114: xs_setup_tcp: RPC: set up xprt to 192.168.23.22 (port 44672) via tcp kworker/u32:1-13473 [000] .... 4093.915122: xprt_create_transport: RPC: created transport ffff8803b1c38000 with 65536 slots kworker/0:1H-129 [000] .... 4093.915152: xprt_alloc_slot: RPC: 47 reserved req ffff88040b27ca00 xid c50ccaff kworker/0:1H-129 [000] .... 4093.915157: xprt_connect: RPC: 47 xprt_connect xprt ffff8803b1c38000 is not connected kworker/0:1H-129 [000] .... 4093.915159: xs_connect: RPC: xs_connect scheduled xprt ffff8803b1c38000 kworker/0:1H-129 [000] ..s. 4093.915170: inet_csk_get_port: snum 892 kworker/0:1H-129 [000] ..s. 4093.915177: <stack trace> => sched_clock => inet_addr_type_table => security_capable => inet_bind => xs_bind => release_sock => sock_setsockopt => __sock_create => xs_create_sock.isra.19 => xs_tcp_setup_socket => process_one_work => worker_thread => worker_thread => kthread => ret_from_fork => kthread kworker/0:1H-129 [000] ..s. 4093.915178: inet_bind_hash: add 892 ffff8803bb9b5cc0 kworker/0:1H-129 [000] ..s. 4093.915184: <stack trace> => inet_csk_get_port => sched_clock => inet_addr_type_table => security_capable => inet_bind => xs_bind => release_sock => sock_setsockopt => __sock_create => xs_create_sock.isra.19 => xs_tcp_setup_socket => process_one_work => worker_thread => worker_thread => kthread => ret_from_fork => kthread kworker/0:1H-129 [000] .... 4093.915185: xs_bind: RPC: xs_bind 4.136.255.255:892: ok (0) kworker/0:1H-129 [000] .... 4093.915186: xs_tcp_setup_socket: RPC: worker connecting xprt ffff8803b1c38000 via tcp to 192.168.23.22 (port 44672) kworker/0:1H-129 [000] .... 4093.915221: xs_tcp_setup_socket: RPC: ffff8803b1c38000 connect status 115 connected 0 sock state 2 <idle>-0 [003] ..s. 4093.915434: xs_tcp_state_change: RPC: xs_tcp_state_change client ffff8803b1c38000... <idle>-0 [003] ..s. 4093.915435: xs_tcp_state_change: RPC: state 1 conn 0 dead 0 zapped 1 sk_shutdown 0 kworker/3:1H-145 [003] .... 4093.915558: xprt_connect_status: RPC: 47 xprt_connect_status: retrying kworker/3:1H-145 [003] .... 4093.915560: xprt_prepare_transmit: RPC: 47 xprt_prepare_transmit kworker/3:1H-145 [003] .... 4093.915562: xprt_transmit: RPC: 47 xprt_transmit(72) kworker/3:1H-145 [003] .... 4093.915588: xs_tcp_send_request: RPC: xs_tcp_send_request(72) = 0 kworker/3:1H-145 [003] .... 4093.915589: xprt_transmit: RPC: 47 xmit complete <idle>-0 [003] ..s. 4093.915969: xs_tcp_data_ready: RPC: xs_tcp_data_ready... kworker/3:1H-145 [003] .... 4093.916081: xs_tcp_data_recv: RPC: xs_tcp_data_recv started kworker/3:1H-145 [003] .... 4093.916083: xs_tcp_data_recv: RPC: reading TCP record fragment of length 24 kworker/3:1H-145 [003] .... 4093.916084: xs_tcp_data_recv: RPC: reading XID (4 bytes) kworker/3:1H-145 [003] .... 4093.916085: xs_tcp_data_recv: RPC: reading request with XID c50ccaff kworker/3:1H-145 [003] .... 4093.916086: xs_tcp_data_recv: RPC: reading CALL/REPLY flag (4 bytes) kworker/3:1H-145 [003] .... 4093.916087: xs_tcp_data_recv: RPC: read reply XID c50ccaff kworker/3:1H-145 [003] ..s. 4093.916088: xs_tcp_data_recv: RPC: XID c50ccaff read 16 bytes kworker/3:1H-145 [003] ..s. 4093.916089: xs_tcp_data_recv: RPC: xprt = ffff8803b1c38000, tcp_copied = 24, tcp_offset = 24, tcp_reclen = 24 kworker/3:1H-145 [003] ..s. 4093.916090: xprt_complete_rqst: RPC: 47 xid c50ccaff complete (24 bytes received) kworker/3:1H-145 [003] .... 4093.916091: xs_tcp_data_recv: RPC: xs_tcp_data_recv done kworker/3:1H-145 [003] .... 4093.916098: xprt_release: RPC: 47 release request ffff88040b27ca00 kworker/u32:1-13473 [002] .... 4093.976056: xprt_destroy: RPC: destroying transport ffff8803b1c38000 kworker/u32:1-13473 [002] .... 4093.976068: xs_destroy: RPC: xs_destroy xprt ffff8803b1c38000 kworker/u32:1-13473 [002] .... 4093.976069: xs_close: RPC: xs_close xprt ffff8803b1c38000 kworker/u32:1-13473 [002] ..s. 4093.976096: xs_tcp_state_change: RPC: xs_tcp_state_change client ffff8803b1c38000... kworker/u32:1-13473 [002] ..s. 4093.976098: xs_tcp_state_change: RPC: state 4 conn 1 dead 0 zapped 1 sk_shutdown 3 kworker/u32:1-13473 [002] .... 4093.976103: xprt_disconnect_done: RPC: disconnected transport ffff8803b1c38000 kworker/u32:1-13473 [002] .... 4093.976104: xprt_disconnect_done: disconnect transport! kworker/u32:1-13473 [002] .... 4093.976113: <stack trace> => xs_destroy => xprt_switch_free => rpc_free_client => rpc_release_client => rpc_shutdown_client => load_balance => ttwu_do_wakeup => nfsd4_process_cb_update.isra.14 => __switch_to => pick_next_task_fair => nfsd4_run_cb_work => process_one_work => worker_thread => worker_thread => kthread => ret_from_fork => kthread Immediately followed by setting up of the port that will eventually turn into the hidden port: kworker/u32:1-13473 [002] .... 4093.976128: xs_setup_tcp: RPC: set up xprt to 192.168.23.22 (port 44672) via tcp kworker/u32:1-13473 [002] .... 4093.976136: xprt_create_transport: RPC: created transport ffff8803b8c22000 with 65536 slots kworker/2:1H-144 [002] .... 4093.976209: xprt_alloc_slot: RPC: 48 reserved req ffff8803bfe89c00 xid 10c028fe kworker/2:1H-144 [002] .... 4093.976213: xprt_connect: RPC: 48 xprt_connect xprt ffff8803b8c22000 is not connected kworker/2:1H-144 [002] .... 4093.976215: xs_connect: RPC: xs_connect scheduled xprt ffff8803b8c22000 kworker/2:1H-144 [002] ..s. 4093.976231: inet_csk_get_port: snum 754 kworker/2:1H-144 [002] ..s. 4093.976239: <stack trace> => sched_clock => inet_addr_type_table => security_capable => inet_bind => xs_bind => release_sock => sock_setsockopt => __sock_create => xs_create_sock.isra.19 => xs_tcp_setup_socket => process_one_work => worker_thread => worker_thread => kthread => ret_from_fork => kthread kworker/2:1H-144 [002] ..s. 4093.976239: inet_bind_hash: add 754 ffff8803afc20e40 kworker/2:1H-144 [002] ..s. 4093.976247: <stack trace> => inet_csk_get_port => sched_clock => inet_addr_type_table => security_capable => inet_bind => xs_bind => release_sock => sock_setsockopt => __sock_create => xs_create_sock.isra.19 => xs_tcp_setup_socket => process_one_work => worker_thread => worker_thread => kthread => ret_from_fork => kthread kworker/2:1H-144 [002] .... 4093.976248: xs_bind: RPC: xs_bind 4.136.255.255:754: ok (0) kworker/2:1H-144 [002] .... 4093.976250: xs_tcp_setup_socket: RPC: worker connecting xprt ffff8803b8c22000 via tcp to 192.168.23.22 (port 44672) kworker/2:1H-144 [002] .... 4093.976284: xs_tcp_setup_socket: RPC: ffff8803b8c22000 connect status 115 connected 0 sock state 2 <idle>-0 [003] ..s. 4093.976456: xs_tcp_state_change: RPC: xs_tcp_state_change client ffff8803b8c22000... <idle>-0 [003] ..s. 4093.976458: xs_tcp_state_change: RPC: state 1 conn 0 dead 0 zapped 1 sk_shutdown 0 kworker/3:1H-145 [003] .... 4093.976588: xprt_connect_status: RPC: 48 xprt_connect_status: retrying kworker/3:1H-145 [003] .... 4093.976590: xprt_prepare_transmit: RPC: 48 xprt_prepare_transmit kworker/3:1H-145 [003] .... 4093.976604: xprt_transmit: RPC: 48 xprt_transmit(72) kworker/3:1H-145 [003] .... 4093.976622: xs_tcp_send_request: RPC: xs_tcp_send_request(72) = 0 kworker/3:1H-145 [003] .... 4093.976623: xprt_transmit: RPC: 48 xmit complete <idle>-0 [003] ..s. 4093.977040: xs_tcp_data_ready: RPC: xs_tcp_data_ready... kworker/3:1H-145 [003] .... 4093.977151: xs_tcp_data_recv: RPC: xs_tcp_data_recv started kworker/3:1H-145 [003] .... 4093.977153: xs_tcp_data_recv: RPC: reading TCP record fragment of length 24 kworker/3:1H-145 [003] .... 4093.977154: xs_tcp_data_recv: RPC: reading XID (4 bytes) kworker/3:1H-145 [003] .... 4093.977155: xs_tcp_data_recv: RPC: reading request with XID 10c028fe kworker/3:1H-145 [003] .... 4093.977156: xs_tcp_data_recv: RPC: reading CALL/REPLY flag (4 bytes) kworker/3:1H-145 [003] .... 4093.977157: xs_tcp_data_recv: RPC: read reply XID 10c028fe kworker/3:1H-145 [003] ..s. 4093.977158: xs_tcp_data_recv: RPC: XID 10c028fe read 16 bytes kworker/3:1H-145 [003] ..s. 4093.977159: xs_tcp_data_recv: RPC: xprt = ffff8803b8c22000, tcp_copied = 24, tcp_offset = 24, tcp_reclen = 24 kworker/3:1H-145 [003] ..s. 4093.977160: xprt_complete_rqst: RPC: 48 xid 10c028fe complete (24 bytes received) kworker/3:1H-145 [003] .... 4093.977161: xs_tcp_data_recv: RPC: xs_tcp_data_recv done kworker/3:1H-145 [003] .... 4093.977167: xprt_release: RPC: 48 release request ffff8803bfe89c00 That "2049" port is what is used for all transferring of data. When the FIN/ACK is sent by the client, the socket is destroyed (no more connections can be used) but the port is not freed up, because it appears there's still an owner attached to it. That means this port will *never* be used again. Even if the client unmount the directory. That port is still in limbo. When the FIN/ACK comes in, it goes into the TIME_WAIT state here: kworker/3:1H-145 [003] ..s. 4394.370019: xs_tcp_state_change: RPC: xs_tcp_state_change client ffff8803b8c22000... kworker/3:1H-145 [003] ..s. 4394.370022: xs_tcp_state_change: RPC: state 4 conn 1 dead 0 zapped 1 sk_shutdown 3 <idle>-0 [003] ..s. 4394.370352: xs_tcp_state_change: RPC: xs_tcp_state_change client ffff8803b8c22000... <idle>-0 [003] ..s. 4394.370354: xs_tcp_state_change: RPC: state 5 conn 0 dead 0 zapped 1 sk_shutdown 3 <idle>-0 [003] ..s. 4394.370375: tcp_time_wait: moving xs_bind sock to time wait <idle>-0 [003] ..s. 4394.370396: <stack trace> => tcp_data_queue => tcp_rcv_state_process => tcp_v4_inbound_md5_hash => tcp_v4_do_rcv => tcp_v4_rcv => ipv4_confirm => nf_iterate => ip_local_deliver_finish => ip_local_deliver => ip_local_deliver_finish => ip_rcv => packet_rcv => ip_rcv_finish => __netif_receive_skb_core => kmem_cache_alloc => netif_receive_skb_internal => br_pass_frame_up => br_flood => br_handle_frame => br_handle_frame_finish => enqueue_task_fair => br_handle_frame => br_handle_frame => find_busiest_group => __netif_receive_skb_core => inet_gro_receive => netif_receive_skb_internal => napi_gro_receive => e1000_clean_rx_irq => e1000_clean => net_rx_action => __do_softirq => irq_exit => do_IRQ => ret_from_intr => cpuidle_enter_state => cpuidle_enter_state => cpu_startup_entry => start_secondary Then eventually, the socket is freed, and 'netstat' no longer shows it. <idle>-0 [003] .Ns. 4454.371802: inet_bind_bucket_destroy: destroy 754 empty=0 ffff8803afc20e40 <idle>-0 [003] .Ns. 4454.371813: <stack trace> => inet_twsk_bind_unhash => inet_twsk_kill => tw_timer_handler => call_timer_fn => tw_timer_handler => run_timer_softirq => __do_softirq => irq_exit => do_IRQ => ret_from_intr => cpuidle_enter_state => cpuidle_enter_state => cpu_startup_entry => start_secondary "empty=0" means the tb->owners associated with the port is not empty, and the freeing of the port is skipped. Now when I go and remount the directory from the client, the code finally cleans up the port: kworker/u32:0-25031 [000] .... 4544.674603: xprt_destroy: RPC: destroying transport ffff8803b8c22000 kworker/u32:0-25031 [000] .... 4544.674616: xs_destroy: RPC: xs_destroy xprt ffff8803b8c22000 kworker/u32:0-25031 [000] .... 4544.674617: xs_close: RPC: xs_close xprt ffff8803b8c22000 kworker/u32:0-25031 [000] ..s. 4544.674619: xs_tcp_state_change: RPC: xs_tcp_state_change client ffff8803b8c22000... kworker/u32:0-25031 [000] ..s. 4544.674620: xs_tcp_state_change: RPC: state 7 conn 0 dead 0 zapped 1 sk_shutdown 3 kworker/u32:0-25031 [000] ..s. 4544.674621: xprt_disconnect_done: RPC: disconnected transport ffff8803b8c22000 kworker/u32:0-25031 [000] ..s. 4544.674621: xprt_disconnect_done: disconnect transport! kworker/u32:0-25031 [000] ..s. 4544.674647: inet_bind_bucket_destroy: destroy 754 empty=1 ffff8803afc20e40 kworker/u32:0-25031 [000] ..s. 4544.674655: <stack trace> => inet_put_port => tcp_v4_destroy_sock => inet_csk_destroy_sock => tcp_close => inet_release => sock_release => xs_close => xs_destroy => xprt_switch_free => rpc_free_client => rpc_release_client => rpc_shutdown_client => nfsd4_process_cb_update.isra.14 => update_curr => dequeue_task_fair => __switch_to => pick_next_task_fair => nfsd4_run_cb_work => process_one_work => worker_thread => worker_thread => kthread => ret_from_fork => kthread kworker/u32:0-25031 [000] .... 4544.674660: xprt_disconnect_done: RPC: disconnected transport ffff8803b8c22000 Notice that "empty=1" now, and the port is freed. Then it goes back doing everything all over again: kworker/3:1H-145 [003] .... 4558.442458: xs_bind: RPC: xs_bind 4.136.255.255:973: ok (0) kworker/3:1H-145 [003] .... 4558.442460: xs_tcp_setup_socket: RPC: worker connecting xprt ffff8803d7fd3800 via tcp to 192.168.23.22 (port 45075) kworker/3:1H-145 [003] .... 4558.442496: xs_tcp_setup_socket: RPC: ffff8803d7fd3800 connect status 115 connected 0 sock state 2 <idle>-0 [002] ..s. 4558.442691: xs_tcp_state_change: RPC: xs_tcp_state_change client ffff8803d7fd3800... <idle>-0 [002] ..s. 4558.442693: xs_tcp_state_change: RPC: state 1 conn 0 dead 0 zapped 1 sk_shutdown 0 kworker/2:1H-144 [002] .... 4558.442732: xprt_connect_status: RPC: 49 xprt_connect_status: retrying kworker/2:1H-144 [002] .... 4558.442734: xprt_prepare_transmit: RPC: 49 xprt_prepare_transmit kworker/2:1H-144 [002] .... 4558.442737: xprt_transmit: RPC: 49 xprt_transmit(72) kworker/2:1H-144 [002] .... 4558.442753: xs_tcp_send_request: RPC: xs_tcp_send_request(72) = 0 kworker/2:1H-144 [002] .... 4558.442754: xprt_transmit: RPC: 49 xmit complete nfsd-4382 [002] ..s. 4558.443203: xs_tcp_data_ready: RPC: xs_tcp_data_ready... kworker/2:1H-144 [002] .... 4558.443227: xs_tcp_data_recv: RPC: xs_tcp_data_recv started kworker/2:1H-144 [002] .... 4558.443229: xs_tcp_data_recv: RPC: reading TCP record fragment of length 24 kworker/2:1H-144 [002] .... 4558.443230: xs_tcp_data_recv: RPC: reading XID (4 bytes) kworker/2:1H-144 [002] .... 4558.443231: xs_tcp_data_recv: RPC: reading request with XID e2e1dc21 kworker/2:1H-144 [002] .... 4558.443232: xs_tcp_data_recv: RPC: reading CALL/REPLY flag (4 bytes) kworker/2:1H-144 [002] .... 4558.443233: xs_tcp_data_recv: RPC: read reply XID e2e1dc21 kworker/2:1H-144 [002] ..s. 4558.443235: xs_tcp_data_recv: RPC: XID e2e1dc21 read 16 bytes kworker/2:1H-144 [002] ..s. 4558.443236: xs_tcp_data_recv: RPC: xprt = ffff8803d7fd3800, tcp_copied = 24, tcp_offset = 24, tcp_reclen = 24 kworker/2:1H-144 [002] ..s. 4558.443237: xprt_complete_rqst: RPC: 49 xid e2e1dc21 complete (24 bytes received) kworker/2:1H-144 [002] .... 4558.443238: xs_tcp_data_recv: RPC: xs_tcp_data_recv done kworker/2:1H-144 [002] .... 4558.443246: xprt_release: RPC: 49 release request ffff8800dba14800 kworker/u32:1-13473 [003] .... 4558.496850: xprt_destroy: RPC: destroying transport ffff8803d7fd3800 kworker/u32:1-13473 [003] .... 4558.496860: xs_destroy: RPC: xs_destroy xprt ffff8803d7fd3800 kworker/u32:1-13473 [003] .... 4558.496861: xs_close: RPC: xs_close xprt ffff8803d7fd3800 kworker/u32:1-13473 [003] ..s. 4558.496888: xs_tcp_state_change: RPC: xs_tcp_state_change client ffff8803d7fd3800... kworker/u32:1-13473 [003] ..s. 4558.496889: xs_tcp_state_change: RPC: state 4 conn 1 dead 0 zapped 1 sk_shutdown 3 kworker/u32:1-13473 [003] .... 4558.496894: xprt_disconnect_done: RPC: disconnected transport ffff8803d7fd3800 kworker/u32:1-13473 [003] .... 4558.496895: xprt_disconnect_done: disconnect transport! Where 973 is the port that gets added and disconnected right away (and freed) kworker/3:1H-145 [003] .... 4558.496991: xs_bind: RPC: xs_bind 4.136.255.255:688: ok (0) kworker/3:1H-145 [003] .... 4558.496993: xs_tcp_setup_socket: RPC: worker connecting xprt ffff8803bb889000 via tcp to 192.168.23.22 (port 45075) kworker/3:1H-145 [003] .... 4558.497024: xs_tcp_setup_socket: RPC: ffff8803bb889000 connect status 115 connected 0 sock state 2 <idle>-0 [002] .Ns. 4558.497171: xs_tcp_state_change: RPC: xs_tcp_state_change client ffff8803bb889000... <idle>-0 [002] .Ns. 4558.497173: xs_tcp_state_change: RPC: state 1 conn 0 dead 0 zapped 1 sk_shutdown 0 kworker/2:1H-144 [002] .... 4558.497196: xprt_connect_status: RPC: 50 xprt_connect_status: retrying kworker/2:1H-144 [002] .... 4558.497197: xprt_prepare_transmit: RPC: 50 xprt_prepare_transmit kworker/2:1H-144 [002] .... 4558.497199: xprt_transmit: RPC: 50 xprt_transmit(72) kworker/2:1H-144 [002] .... 4558.497210: xs_tcp_send_request: RPC: xs_tcp_send_request(72) = 0 kworker/2:1H-144 [002] .... 4558.497210: xprt_transmit: RPC: 50 xmit complete <idle>-0 [002] ..s. 4558.497475: xs_tcp_data_ready: RPC: xs_tcp_data_ready... kworker/2:1H-144 [002] .... 4558.497569: xs_tcp_data_recv: RPC: xs_tcp_data_recv started kworker/2:1H-144 [002] .... 4558.497571: xs_tcp_data_recv: RPC: reading TCP record fragment of length 24 kworker/2:1H-144 [002] .... 4558.497571: xs_tcp_data_recv: RPC: reading XID (4 bytes) kworker/2:1H-144 [002] .... 4558.497572: xs_tcp_data_recv: RPC: reading request with XID a4418f34 kworker/2:1H-144 [002] .... 4558.497573: xs_tcp_data_recv: RPC: reading CALL/REPLY flag (4 bytes) kworker/2:1H-144 [002] .... 4558.497573: xs_tcp_data_recv: RPC: read reply XID a4418f34 kworker/2:1H-144 [002] ..s. 4558.497574: xs_tcp_data_recv: RPC: XID a4418f34 read 16 bytes kworker/2:1H-144 [002] ..s. 4558.497575: xs_tcp_data_recv: RPC: xprt = ffff8803bb889000, tcp_copied = 24, tcp_offset = 24, tcp_reclen = 24 kworker/2:1H-144 [002] ..s. 4558.497575: xprt_complete_rqst: RPC: 50 xid a4418f34 complete (24 bytes received) kworker/2:1H-144 [002] .... 4558.497577: xs_tcp_data_recv: RPC: xs_tcp_data_recv done kworker/2:1H-144 [002] .... 4558.497581: xprt_release: RPC: 50 release request ffff8800db28d800 And 688 will be the port that becomes the new hidden port. Thus it looks like there's something that is not cleaning up ports properly. There's some timing issues here. Any thoughts why. Because this is obviously wrong, and not only is it wasting a port and memory to store it, but it's causing rkhunter to report it, because it's one of the things that rootkits do. -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
--- net/ipv4/inet_connection_sock.c | 4 ++++ net/ipv4/inet_hashtables.c | 5 +++++ net/sunrpc/xprt.c | 5 +++++ net/sunrpc/xprtsock.c | 5 +++++ 5 files changed, 22 insertions(+) Index: linux-build.git/net/ipv4/inet_connection_sock.c =================================================================== --- linux-build.git.orig/net/ipv4/inet_connection_sock.c 2016-06-22 11:55:05.952267493 -0400 +++ linux-build.git/net/ipv4/inet_connection_sock.c 2016-06-22 11:56:20.002662092 -0400 @@ -232,6 +232,10 @@ tb_found: } } success: + if (!current->mm) { + trace_printk("snum %d\n", snum); + trace_dump_stack(1); + } if (!inet_csk(sk)->icsk_bind_hash) inet_bind_hash(sk, tb, port); WARN_ON(inet_csk(sk)->icsk_bind_hash != tb); Index: linux-build.git/net/ipv4/inet_hashtables.c =================================================================== --- linux-build.git.orig/net/ipv4/inet_hashtables.c 2016-06-22 11:55:05.952267493 -0400 +++ linux-build.git/net/ipv4/inet_hashtables.c 2016-06-22 11:55:05.948267360 -0400 @@ -93,6 +93,11 @@ void inet_bind_bucket_destroy(struct kme void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb, const unsigned short snum) { + if (!current->mm) { + trace_printk("add %d\n", snum); + trace_dump_stack(1); + } + inet_sk(sk)->inet_num = snum; sk_add_bind_node(sk, &tb->owners); tb->num_owners++; Index: linux-build.git/net/sunrpc/xprt.c =================================================================== --- linux-build.git.orig/net/sunrpc/xprt.c 2016-06-22 11:55:05.952267493 -0400 +++ linux-build.git/net/sunrpc/xprt.c 2016-06-22 11:55:05.948267360 -0400 @@ -54,6 +54,11 @@ #include "sunrpc.h" +#undef dprintk +#undef dprintk_rcu +#define dprintk(args...) trace_printk(args) +#define dprintk_rcu(args...) trace_printk(args) + /* * Local variables */ Index: linux-build.git/net/sunrpc/xprtsock.c =================================================================== --- linux-build.git.orig/net/sunrpc/xprtsock.c 2016-06-22 11:55:05.952267493 -0400 +++ linux-build.git/net/sunrpc/xprtsock.c 2016-06-22 11:55:05.948267360 -0400 @@ -51,6 +51,11 @@ #include "sunrpc.h" +#undef dprintk +#undef dprintk_rcu +#define dprintk(args...) trace_printk(args) +#define dprintk_rcu(args...) trace_printk(args) + static void xs_close(struct rpc_xprt *xprt); /*
[ resending as a new email, as I'm assuming people do not sort their INBOX via last email on thread, thus my last email is sitting in the bottom of everyone's INBOX ] I've hit this again. Not sure when it started, but I applied my old debug trace_printk() patch (attached) and rebooted (4.5.7). I just tested the latest kernel from Linus's tree (from last nights pull), and it still gives me the problem. Here's the trace I have: kworker/3:1H-134 [003] ..s. 61.036129: inet_csk_get_port: snum 805 kworker/3:1H-134 [003] ..s. 61.036135: <stack trace> => sched_clock => inet_addr_type_table => security_capable => inet_bind => xs_bind => release_sock => sock_setsockopt => __sock_create => xs_create_sock.isra.19 => xs_tcp_setup_socket => process_one_work => worker_thread => worker_thread => kthread => ret_from_fork => kthread kworker/3:1H-134 [003] ..s. 61.036136: inet_bind_hash: add 805 kworker/3:1H-134 [003] ..s. 61.036138: <stack trace> => inet_csk_get_port => sched_clock => inet_addr_type_table => security_capable => inet_bind => xs_bind => release_sock => sock_setsockopt => __sock_create => xs_create_sock.isra.19 => xs_tcp_setup_socket => process_one_work => worker_thread => worker_thread => kthread => ret_from_fork => kthread kworker/3:1H-134 [003] .... 61.036139: xs_bind: RPC: xs_bind 4.136.255.255:805: ok (0) kworker/3:1H-134 [003] .... 61.036140: xs_tcp_setup_socket: RPC: worker connecting xprt ffff880407eca800 via tcp to 192.168.23.22 (port 43651) kworker/3:1H-134 [003] .... 61.036162: xs_tcp_setup_socket: RPC: ffff880407eca800 connect status 115 connected 0 sock state 2 <idle>-0 [001] ..s. 61.036450: xs_tcp_state_change: RPC: xs_tcp_state_change client ffff880407eca800... <idle>-0 [001] ..s. 61.036452: xs_tcp_state_change: RPC: state 1 conn 0 dead 0 zapped 1 sk_shutdown 0 kworker/1:1H-136 [001] .... 61.036476: xprt_connect_status: RPC: 43 xprt_connect_status: retrying kworker/1:1H-136 [001] .... 61.036478: xprt_prepare_transmit: RPC: 43 xprt_prepare_transmit kworker/1:1H-136 [001] .... 61.036479: xprt_transmit: RPC: 43 xprt_transmit(72) kworker/1:1H-136 [001] .... 61.036486: xs_tcp_send_request: RPC: xs_tcp_send_request(72) = 0 kworker/1:1H-136 [001] .... 61.036487: xprt_transmit: RPC: 43 xmit complete <idle>-0 [001] ..s. 61.036789: xs_tcp_data_ready: RPC: xs_tcp_data_ready... kworker/1:1H-136 [001] .... 61.036798: xs_tcp_data_recv: RPC: xs_tcp_data_recv started kworker/1:1H-136 [001] .... 61.036799: xs_tcp_data_recv: RPC: reading TCP record fragment of length 24 kworker/1:1H-136 [001] .... 61.036799: xs_tcp_data_recv: RPC: reading XID (4 bytes) kworker/1:1H-136 [001] .... 61.036800: xs_tcp_data_recv: RPC: reading request with XID 2f4c3f88 kworker/1:1H-136 [001] .... 61.036800: xs_tcp_data_recv: RPC: reading CALL/REPLY flag (4 bytes) kworker/1:1H-136 [001] .... 61.036801: xs_tcp_data_recv: RPC: read reply XID 2f4c3f88 kworker/1:1H-136 [001] ..s. 61.036801: xs_tcp_data_recv: RPC: XID 2f4c3f88 read 16 bytes kworker/1:1H-136 [001] ..s. 61.036802: xs_tcp_data_recv: RPC: xprt = ffff880407eca800, tcp_copied = 24, tcp_offset = 24, tcp_reclen = 24 kworker/1:1H-136 [001] ..s. 61.036802: xprt_complete_rqst: RPC: 43 xid 2f4c3f88 complete (24 bytes received) kworker/1:1H-136 [001] .... 61.036803: xs_tcp_data_recv: RPC: xs_tcp_data_recv done kworker/1:1H-136 [001] .... 61.036812: xprt_release: RPC: 43 release request ffff88040b270800 # unhide-tcp Unhide-tcp 20130526 Copyright © 2013 Yago Jesus & Patrick Gouin License GPLv3+ : GNU GPL version 3 or later http://www.unhide-forensics.info Used options: [*]Starting TCP checking Found Hidden port that not appears in ss: 805 -- Steve