linux-stable.git/drivers/target, branch v4.4.99

target: Fix node_acl demo-mode + uncached dynamic shutdown regression

2017-11-18T10:11:07+00:00

commit 6f48655facfd7f7ccfe6d252ac0fe319ab02e4dd upstream.

This patch fixes a generate_node_acls = 1 + cache_dynamic_acls = 0
regression, that was introduced by

  commit 01d4d673558985d9a118e1e05026633c3e2ade9b
  Author: Nicholas Bellinger 
  Date:   Wed Dec 7 12:55:54 2016 -0800

which originally had the proper list_del_init() usage, but was
dropped during list review as it was thought unnecessary by HCH.

However, list_del_init() usage is required during the special
generate_node_acls = 1 + cache_dynamic_acls = 0 case when
transport_free_session() does a list_del(&se_nacl->acl_list),
followed by target_complete_nacl() doing the same thing.

This was manifesting as a general protection fault as reported
by Justin:

kernel: general protection fault: 0000 [#1] SMP
kernel: Modules linked in:
kernel: CPU: 0 PID: 11047 Comm: iscsi_ttx Not tainted 4.13.0-rc2.x86_64.1+ #20
kernel: Hardware name: Intel Corporation S5500BC/S5500BC, BIOS S5500.86B.01.00.0064.050520141428 05/05/2014
kernel: task: ffff88026939e800 task.stack: ffffc90007884000
kernel: RIP: 0010:target_put_nacl+0x49/0xb0
kernel: RSP: 0018:ffffc90007887d70 EFLAGS: 00010246
kernel: RAX: dead000000000200 RBX: ffff8802556ca000 RCX: 0000000000000000
kernel: RDX: dead000000000100 RSI: 0000000000000246 RDI: ffff8802556ce028
kernel: RBP: ffffc90007887d88 R08: 0000000000000001 R09: 0000000000000000
kernel: R10: ffffc90007887df8 R11: ffffea0009986900 R12: ffff8802556ce020
kernel: R13: ffff8802556ce028 R14: ffff8802556ce028 R15: ffffffff88d85540
kernel: FS:  0000000000000000(0000) GS:ffff88027fc00000(0000) knlGS:0000000000000000
kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
kernel: CR2: 00007fffe36f5f94 CR3: 0000000009209000 CR4: 00000000003406f0
kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
kernel: Call Trace:
kernel:  transport_free_session+0x67/0x140
kernel:  transport_deregister_session+0x7a/0xc0
kernel:  iscsit_close_session+0x92/0x210
kernel:  iscsit_close_connection+0x5f9/0x840
kernel:  iscsit_take_action_for_connection_exit+0xfe/0x110
kernel:  iscsi_target_tx_thread+0x140/0x1e0
kernel:  ? wait_woken+0x90/0x90
kernel:  kthread+0x124/0x160
kernel:  ? iscsit_thread_get_cpumask+0x90/0x90
kernel:  ? kthread_create_on_node+0x40/0x40
kernel:  ret_from_fork+0x22/0x30
kernel: Code: 00 48 89 fb 4c 8b a7 48 01 00 00 74 68 4d 8d 6c 24 08 4c
89 ef e8 e8 28 43 00 48 8b 93 20 04 00 00 48 8b 83 28 04 00 00 4c 89
ef <48> 89 42 08 48 89 10 48 b8 00 01 00 00 00 00 ad de 48 89 83 20
kernel: RIP: target_put_nacl+0x49/0xb0 RSP: ffffc90007887d70
kernel: ---[ end trace f12821adbfd46fed ]---

To address this, go ahead and use proper list_del_list() for all
cases of se_nacl->acl_list deletion.

Reported-by: Justin Maggard 
Tested-by: Justin Maggard 
Cc: Justin Maggard 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

target/iscsi: Fix iSCSI task reassignment handling

2017-11-18T10:11:07+00:00

commit 59b6986dbfcdab96a971f9663221849de79a7556 upstream.

Allocate a task management request structure for all task management
requests, including task reassignment. This change avoids that the
se_tmr->response assignment dereferences an uninitialized se_tmr
pointer.

Reported-by: Moshe David 
Signed-off-by: Bart Van Assche 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Christoph Hellwig 
Cc: Moshe David 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

target/iscsi: Fix unsolicited data seq_end_offset calculation

2017-10-21T15:09:06+00:00

[ Upstream commit 4d65491c269729a1e3b375c45e73213f49103d33 ]

In case of unsolicited data for the first sequence
seq_end_offset must be set to minimum of total data length
and FirstBurstLength, so do not add cmd->write_data_done
to the min of total data length and FirstBurstLength.

This patch avoids that with ImmediateData=Yes, InitialR2T=No,
MaxXmitDataSegmentLength < FirstBurstLength that a WRITE command
with IO size above FirstBurstLength triggers sequence error
messages, for example

Set following parameters on target (linux-4.8.12)
ImmediateData = Yes
InitialR2T = No
MaxXmitDataSegmentLength = 8k
FirstBurstLength = 64k

Log in from Open iSCSI initiator and execute
dd if=/dev/zero of=/dev/sdb bs=128k count=1 oflag=direct

Error messages on target
Command ITT: 0x00000035 with Offset: 65536, Length: 8192 outside
of Sequence 73728:131072 while DataSequenceInOrder=Yes.
Command ITT: 0x00000035, received DataSN: 0x00000001 higher than
expected 0x00000000.
Unable to perform within-command recovery while ERL=0.

Signed-off-by: Varun Prakash 
[ bvanassche: Use min() instead of open-coding it / edited patch description ]
Signed-off-by: Bart Van Assche 
Signed-off-by: Nicholas Bellinger 

Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

iscsi-target: Fix iscsi_np reset hung task during parallel delete

2017-08-16T20:40:28+00:00

commit 978d13d60c34818a41fc35962602bdfa5c03f214 upstream.

This patch fixes a bug associated with iscsit_reset_np_thread()
that can occur during parallel configfs rmdir of a single iscsi_np
used across multiple iscsi-target instances, that would result in
hung task(s) similar to below where configfs rmdir process context
was blocked indefinately waiting for iscsi_np->np_restart_comp
to finish:

[ 6726.112076] INFO: task dcp_proxy_node_:15550 blocked for more than 120 seconds.
[ 6726.119440]       Tainted: G        W  O     4.1.26-3321 #2
[ 6726.125045] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 6726.132927] dcp_proxy_node_ D ffff8803f202bc88     0 15550      1 0x00000000
[ 6726.140058]  ffff8803f202bc88 ffff88085c64d960 ffff88083b3b1ad0 ffff88087fffeb08
[ 6726.147593]  ffff8803f202c000 7fffffffffffffff ffff88083f459c28 ffff88083b3b1ad0
[ 6726.155132]  ffff88035373c100 ffff8803f202bca8 ffffffff8168ced2 ffff8803f202bcb8
[ 6726.162667] Call Trace:
[ 6726.165150]  [] schedule+0x32/0x80
[ 6726.170156]  [] schedule_timeout+0x214/0x290
[ 6726.176030]  [] ? __send_signal+0x52/0x4a0
[ 6726.181728]  [] wait_for_completion+0x96/0x100
[ 6726.187774]  [] ? wake_up_state+0x10/0x10
[ 6726.193395]  [] iscsit_reset_np_thread+0x62/0xe0 [iscsi_target_mod]
[ 6726.201278]  [] iscsit_tpg_disable_portal_group+0x96/0x190 [iscsi_target_mod]
[ 6726.210033]  [] lio_target_tpg_store_enable+0x4f/0xc0 [iscsi_target_mod]
[ 6726.218351]  [] configfs_write_file+0xaa/0x110
[ 6726.224392]  [] vfs_write+0xa4/0x1b0
[ 6726.229576]  [] SyS_write+0x41/0xb0
[ 6726.234659]  [] system_call_fastpath+0x12/0x71

It would happen because each iscsit_reset_np_thread() sets state
to ISCSI_NP_THREAD_RESET, sends SIGINT, and then blocks waiting
for completion on iscsi_np->np_restart_comp.

However, if iscsi_np was active processing a login request and
more than a single iscsit_reset_np_thread() caller to the same
iscsi_np was blocked on iscsi_np->np_restart_comp, iscsi_np
kthread process context in __iscsi_target_login_thread() would
flush pending signals and only perform a single completion of
np->np_restart_comp before going back to sleep within transport
specific iscsit_transport->iscsi_accept_np code.

To address this bug, add a iscsi_np->np_reset_count and update
__iscsi_target_login_thread() to keep completing np->np_restart_comp
until ->np_reset_count has reached zero.

Reported-by: Gary Guo 
Tested-by: Gary Guo 
Cc: Mike Christie 
Cc: Hannes Reinecke 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

iscsi-target: fix memory leak in iscsit_setup_text_cmd()

2017-08-16T20:40:28+00:00

commit ea8dc5b4cd2195ee582cae28afa4164c6dea1738 upstream.

On receiving text request iscsi-target allocates buffer for
payload in iscsit_handle_text_cmd() and assigns buffer pointer
to cmd->text_in_ptr, this buffer is currently freed in
iscsit_release_cmd(), if iscsi-target sets 'C' bit in text
response then it will receive another text request from the
initiator with ttt != 0xffffffff in this case iscsi-target
will find cmd using itt and call iscsit_setup_text_cmd()
which will set cmd->text_in_ptr to NULL without freeing
previously allocated buffer.

This patch fixes this issue by calling kfree(cmd->text_in_ptr)
in iscsit_setup_text_cmd() before assigning NULL to it.

For the first text request cmd->text_in_ptr is NULL as
cmd is memset to 0 in iscsit_allocate_cmd().

Signed-off-by: Varun Prakash 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

iscsi-target: Fix delayed logout processing greater than SECONDS_FOR_LOGOUT_COMP

2017-08-11T16:08:50+00:00

commit 105fa2f44e504c830697b0c794822112d79808dc upstream.

This patch fixes a BUG() in iscsit_close_session() that could be
triggered when iscsit_logout_post_handler() execution from within
tx thread context was not run for more than SECONDS_FOR_LOGOUT_COMP
(15 seconds), and the TCP connection didn't already close before
then forcing tx thread context to automatically exit.

This would manifest itself during explicit logout as:

[33206.974254] 1 connection(s) still exist for iSCSI session to iqn.1993-08.org.debian:01:3f5523242179
[33206.980184] INFO: NMI handler (kgdb_nmi_handler) took too long to run: 2100.772 msecs
[33209.078643] ------------[ cut here ]------------
[33209.078646] kernel BUG at drivers/target/iscsi/iscsi_target.c:4346!

Normally when explicit logout attempt fails, the tx thread context
exits and iscsit_close_connection() from rx thread context does the
extra cleanup once it detects conn->conn_logout_remove has not been
cleared by the logout type specific post handlers.

To address this special case, if the logout post handler in tx thread
context detects conn->tx_thread_active has already been cleared, simply
return and exit in order for existing iscsit_close_connection()
logic from rx thread context do failed logout cleanup.

Reported-by: Bart Van Assche 
Tested-by: Bart Van Assche 
Cc: Mike Christie 
Cc: Hannes Reinecke 
Cc: Sagi Grimberg 
Tested-by: Gary Guo 
Tested-by: Chu Yuan Lin 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

iscsi-target: Fix initial login PDU asynchronous socket close OOPs

2017-08-11T16:08:49+00:00

commit 25cdda95fda78d22d44157da15aa7ea34be3c804 upstream.

This patch fixes a OOPs originally introduced by:

   commit bb048357dad6d604520c91586334c9c230366a14
   Author: Nicholas Bellinger 
   Date:   Thu Sep 5 14:54:04 2013 -0700

   iscsi-target: Add sk->sk_state_change to cleanup after TCP failure

which would trigger a NULL pointer dereference when a TCP connection
was closed asynchronously via iscsi_target_sk_state_change(), but only
when the initial PDU processing in iscsi_target_do_login() from iscsi_np
process context was blocked waiting for backend I/O to complete.

To address this issue, this patch makes the following changes.

First, it introduces some common helper functions used for checking
socket closing state, checking login_flags, and atomically checking
socket closing state + setting login_flags.

Second, it introduces a LOGIN_FLAGS_INITIAL_PDU bit to know when a TCP
connection has dropped via iscsi_target_sk_state_change(), but the
initial PDU processing within iscsi_target_do_login() in iscsi_np
context is still running.  For this case, it sets LOGIN_FLAGS_CLOSED,
but doesn't invoke schedule_delayed_work().

The original NULL pointer dereference case reported by MNC is now handled
by iscsi_target_do_login() doing a iscsi_target_sk_check_close() before
transitioning to FFP to determine when the socket has already closed,
or iscsi_target_start_negotiation() if the login needs to exchange
more PDUs (eg: iscsi_target_do_login returned 0) but the socket has
closed.  For both of these cases, the cleanup up of remaining connection
resources will occur in iscsi_target_start_negotiation() from iscsi_np
process context once the failure is detected.

Finally, to handle to case where iscsi_target_sk_state_change() is
called after the initial PDU procesing is complete, it now invokes
conn->login_work -> iscsi_target_do_login_rx() to perform cleanup once
existing iscsi_target_sk_check_close() checks detect connection failure.
For this case, the cleanup of remaining connection resources will occur
in iscsi_target_do_login_rx() from delayed workqueue process context
once the failure is detected.

Reported-by: Mike Christie 
Reviewed-by: Mike Christie 
Tested-by: Mike Christie 
Cc: Mike Christie 
Reported-by: Hannes Reinecke 
Cc: Hannes Reinecke 
Cc: Sagi Grimberg 
Cc: Varun Prakash 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

iscsi-target: Fix early sk_data_ready LOGIN_FLAGS_READY race

2017-08-11T16:08:49+00:00

commit 8f0dfb3d8b1120c61f6e2cc3729290db10772b2d upstream.

There is a iscsi-target/tcp login race in LOGIN_FLAGS_READY
state assignment that can result in frequent errors during
iscsi discovery:

      "iSCSI Login negotiation failed."

To address this bug, move the initial LOGIN_FLAGS_READY
assignment ahead of iscsi_target_do_login() when handling
the initial iscsi_target_start_negotiation() request PDU
during connection login.

As iscsi_target_do_login_rx() work_struct callback is
clearing LOGIN_FLAGS_READ_ACTIVE after subsequent calls
to iscsi_target_do_login(), the early sk_data_ready
ahead of the first iscsi_target_do_login() expects
LOGIN_FLAGS_READY to also be set for the initial
login request PDU.

As reported by Maged, this was first obsered using an
MSFT initiator running across multiple VMWare host
virtual machines with iscsi-target/tcp.

Reported-by: Maged Mokhtar 
Tested-by: Maged Mokhtar 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

iscsi-target: Always wait for kthread_should_stop() before kthread exit

2017-08-11T16:08:49+00:00

commit 5e0cf5e6c43b9e19fc0284f69e5cd2b4a47523b0 upstream.

There are three timing problems in the kthread usages of iscsi_target_mod:

 - np_thread of struct iscsi_np
 - rx_thread and tx_thread of struct iscsi_conn

In iscsit_close_connection(), it calls

 send_sig(SIGINT, conn->tx_thread, 1);
 kthread_stop(conn->tx_thread);

In conn->tx_thread, which is iscsi_target_tx_thread(), when it receive
SIGINT the kthread will exit without checking the return value of
kthread_should_stop().

So if iscsi_target_tx_thread() exit right between send_sig(SIGINT...)
and kthread_stop(...), the kthread_stop() will try to stop an already
stopped kthread.

This is invalid according to the documentation of kthread_stop().

(Fix -ECONNRESET logout handling in iscsi_target_tx_thread and
 early iscsi_target_rx_thread failure case - nab)

Signed-off-by: Jiang Yi 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

target: Avoid mappedlun symlink creation during lun shutdown

2017-08-11T16:08:49+00:00

commit 49cb77e297dc611a1b795cfeb79452b3002bd331 upstream.

This patch closes a race between se_lun deletion during configfs
unlink in target_fabric_port_unlink() -> core_dev_del_lun()
-> core_tpg_remove_lun(), when transport_clear_lun_ref() blocks
waiting for percpu_ref RCU grace period to finish, but a new
NodeACL mappedlun is added before the RCU grace period has
completed.

This can happen in target_fabric_mappedlun_link() because it
only checks for se_lun->lun_se_dev, which is not cleared until
after transport_clear_lun_ref() percpu_ref RCU grace period
finishes.

This bug originally manifested as NULL pointer dereference
OOPsen in target_stat_scsi_att_intr_port_show_attr_dev() on
v4.1.y code, because it dereferences lun->lun_se_dev without
a explicit NULL pointer check.

In post v4.1 code with target-core RCU conversion, the code
in target_stat_scsi_att_intr_port_show_attr_dev() no longer
uses se_lun->lun_se_dev, but the same race still exists.

To address the bug, go ahead and set se_lun>lun_shutdown as
early as possible in core_tpg_remove_lun(), and ensure new
NodeACL mappedlun creation in target_fabric_mappedlun_link()
fails during se_lun shutdown.

Reported-by: James Shen 
Cc: James Shen 
Tested-by: James Shen 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman