linux-stable.git/drivers/target, branch linux-3.12.y

iscsi-target: Drop work-around for legacy GlobalSAN initiator

2017-04-28T17:30:44+00:00

commit 1c99de981f30b3e7868b8d20ce5479fa1c0fea46 upstream.

Once upon a time back in 2009, a work-around was added to support
the GlobalSAN iSCSI initiator v3.3 for MacOSX, which during login
did not propose nor respond to MaxBurstLength, FirstBurstLength,
DefaultTime2Wait and DefaultTime2Retain keys.

The work-around in iscsi_check_proposer_for_optional_reply()
allowed the missing keys to be proposed, but did not require
waiting for a response before moving to full feature phase
operation.  This allowed GlobalSAN v3.3 to work out-of-the
box, and for many years we didn't run into login interopt
issues with any other initiators..

Until recently, when Martin tried a QLogic 57840S iSCSI Offload
HBA on Windows 2016 which completed login, but subsequently
failed with:

    Got unknown iSCSI OpCode: 0x43

The issue was QLogic MSFT side did not propose DefaultTime2Wait +
DefaultTime2Retain, so LIO proposes them itself, and immediately
transitions to full feature phase because of the GlobalSAN hack.
However, the QLogic MSFT side still attempts to respond to
DefaultTime2Retain + DefaultTime2Wait, even though LIO has set
ISCSI_FLAG_LOGIN_NEXT_STAGE3 + ISCSI_FLAG_LOGIN_TRANSIT
in last login response.

So while the QLogic MSFT side should have been proposing these
two keys to start, it was doing the correct thing per RFC-3720
attempting to respond to proposed keys before transitioning to
full feature phase.

All that said, recent versions of GlobalSAN iSCSI (v5.3.0.541)
does correctly propose the four keys during login, making the
original work-around moot.

So in order to allow QLogic MSFT to run unmodified as-is, go
ahead and drop this long standing work-around.

Reported-by: Martin Svec 
Cc: Martin Svec 
Cc: Himanshu Madhani 
Cc: Arun Easi 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Jiri Slaby

iscsi-target: Fix TMR reference leak during session shutdown

2017-04-28T17:30:43+00:00

commit efb2ea770bb3b0f40007530bc8b0c22f36e1c5eb upstream.

This patch fixes a iscsi-target specific TMR reference leak
during session shutdown, that could occur when a TMR was
quiesced before the hand-off back to iscsi-target code
via transport_cmd_check_stop_to_fabric().

The reference leak happens because iscsit_free_cmd() was
incorrectly skipping the final target_put_sess_cmd() for
TMRs when transport_generic_free_cmd() returned zero because
the se_cmd->cmd_kref did not reach zero, due to the missing
se_cmd assignment in original code.

The result was iscsi_cmd and it's associated se_cmd memory
would be freed once se_sess->sess_cmd_map where released,
but the associated se_tmr_req was leaked and remained part
of se_device->dev_tmr_list.

This bug would manfiest itself as kernel paging request
OOPsen in core_tmr_lun_reset(), when a left-over se_tmr_req
attempted to dereference it's se_cmd pointer that had
already been released during normal session shutdown.

To address this bug, go ahead and treat ISCSI_OP_SCSI_CMD
and ISCSI_OP_SCSI_TMFUNC the same when there is an extra
se_cmd->cmd_kref to drop in iscsit_free_cmd(), and use
op_scsi to signal __iscsit_free_cmd() when the former
needs to clear any further iscsi related I/O state.

Reported-by: Rob Millner 
Cc: Rob Millner 
Reported-by: Chu Yuan Lin 
Cc: Chu Yuan Lin 
Tested-by: Chu Yuan Lin 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Jiri Slaby

target/pscsi: Fix TYPE_TAPE + TYPE_MEDIMUM_CHANGER export

2017-04-07T07:17:50+00:00

commit a04e54f2c35823ca32d56afcd5cea5b783e2f51a upstream.

The following fixes a divide by zero OOPs with TYPE_TAPE
due to pscsi_tape_read_blocksize() failing causing a zero
sd->sector_size being propigated up via dev_attrib.hw_block_size.

It also fixes another long-standing bug where TYPE_TAPE and
TYPE_MEDIMUM_CHANGER where using pscsi_create_type_other(),
which does not call scsi_device_get() to take the device
reference.  Instead, rename pscsi_create_type_rom() to
pscsi_create_type_nondisk() and use it for all cases.

Finally, also drop a dump_stack() in pscsi_get_blocks() for
non TYPE_DISK, which in modern target-core can get invoked
via target_sense_desc_format() during CHECK_CONDITION.

[js] cast max_sectors to unsigned to avoid warnings

Reported-by: Malcolm Haak 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Jiri Slaby

target: Fix COMPARE_AND_WRITE ref leak for non GOOD status

2017-02-16T10:44:43+00:00

commit 9b2792c3da1e80f2d460167d319302a24c9ca2b7 upstream.

This patch addresses a long standing bug where the commit phase
of COMPARE_AND_WRITE would result in a se_cmd->cmd_kref reference
leak if se_cmd->scsi_status returned non SAM_STAT_GOOD.

This would manifest first as a lost SCSI response, and eventual
hung task during fabric driver logout or re-login, as existing
shutdown logic waited for the COMPARE_AND_WRITE se_cmd->cmd_kref
to reach zero.

To address this bug, compare_and_write_post() has been changed
to drop the incorrect !cmd->scsi_status conditional that was
preventing *post_ret = 1 for being set during non SAM_STAT_GOOD
status.

This patch has been tested with SAM_STAT_CHECK_CONDITION status
from normal target_complete_cmd() callback path, as well as the
incoming __target_execute_cmd() submission failure path when
se_cmd->execute_cmd() returns non zero status.

Reported-by: Donald White 
Cc: Donald White 
Tested-by: Gary Guo 
Cc: Gary Guo 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Jiri Slaby

target/iscsi: Fix double free in lio_target_tiqn_addtpg()

2017-01-26T16:40:16+00:00

commit a91918cd3ea11f91c68e08e1e8ce1b560447a80e upstream.

This iscsit_tpg_add_portal_group() function is only called from
lio_target_tiqn_addtpg().  Both functions free the "tpg" pointer on
error so it's a double free bug.  The memory is allocated in the caller
so it should be freed in the caller and not here.

Fixes: e48354ce078c ("iscsi-target: Add iSCSI fabric support for target v4.1")
Signed-off-by: Dan Carpenter 
Reviewed-by: David Disseldorp 
[ bvanassche: Added "Fix" at start of patch title ]
Signed-off-by: Bart Van Assche 
Signed-off-by: Jiri Slaby

target: Fix target_release_cmd_kref shutdown comp leak

2016-04-11T14:44:24+00:00

commit 5e47f1985d7107331c3f64fb3ec83d66fd73577e upstream.

This patch fixes an active I/O shutdown bug for fabric
drivers using target_wait_for_sess_cmds(), where se_cmd
descriptor shutdown would result in hung tasks waiting
indefinitely for se_cmd->cmd_wait_comp to complete().

To address this bug, drop the incorrect list_del_init()
usage in target_wait_for_sess_cmds() and always complete()
during se_cmd target_release_cmd_kref() put, in order to
let caller invoke the final fabric release callback
into se_cmd->se_tfo->release_cmd() code.

[3.12 backport: we have only list_del]

Reported-by: Himanshu Madhani 
Tested-by: Himanshu Madhani 
Signed-off-by: Himanshu Madhani 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Jiri Slaby

target: fix COMPARE_AND_WRITE non zero SGL offset data corruption

2016-03-03T11:45:57+00:00

commit d94e5a61357a04938ce14d6033b4d33a3c5fd780 upstream.

target_core_sbc's compare_and_write functionality suffers from taking
data at the wrong memory location when writing a CAW request to disk
when a SGL offset is non-zero.

This can happen with loopback and vhost-scsi fabric drivers when
SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC is used to map existing user-space
SGL memory into COMPARE_AND_WRITE READ/WRITE payload buffers.

Given the following sample LIO subtopology,

% targetcli ls /loopback/
o- loopback ................................. [1 Target]
  o- naa.6001405ebb8df14a ....... [naa.60014059143ed2b3]
    o- luns ................................... [2 LUNs]
      o- lun0 ................ [iblock/ram0 (/dev/ram0)]
      o- lun1 ................ [iblock/ram1 (/dev/ram1)]
% lsscsi -g
[3:0:1:0]    disk    LIO-ORG  IBLOCK           4.0   /dev/sdc   /dev/sg3
[3:0:1:1]    disk    LIO-ORG  IBLOCK           4.0   /dev/sdd   /dev/sg4

the following bug can be observed in Linux 4.3 and 4.4~rc1:

% perl -e 'print chr$_ for 0..255,reverse 0..255' >rand
% perl -e 'print "\0" x 512' >zero
% cat rand >/dev/sdd
% sg_compare_and_write -i rand -D zero --lba 0 /dev/sdd
% sg_compare_and_write -i zero -D rand --lba 0 /dev/sdd
Miscompare reported
% hexdump -Cn 512 /dev/sdd
00000000  0f 0e 0d 0c 0b 0a 09 08  07 06 05 04 03 02 01 00
00000010  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00
*
00000200

Rather than writing all-zeroes as instructed with the -D file, it
corrupts the data in the sector by splicing some of the original
bytes in. The page of the first entry of cmd->t_data_sg includes the
CDB, and sg->offset is set to a position past the CDB. I presume that
sg->offset is also the right choice to use for subsequent sglist
members.

Signed-off-by: Jan Engelhardt 
Tested-by: Douglas Gilbert 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Jiri Slaby

target: Fix race for SCF_COMPARE_AND_WRITE_POST checking

2016-03-03T11:45:57+00:00

commit 057085e522f8bf94c2e691a5b76880f68060f8ba upstream.

This patch addresses a race + use after free where the first
stage of COMPARE_AND_WRITE in compare_and_write_callback()
is rescheduled after the backend sends the secondary WRITE,
resulting in second stage compare_and_write_post() callback
completing in target_complete_ok_work() before the first
can return.

Because current code depends on checking se_cmd->se_cmd_flags
after return from se_cmd->transport_complete_callback(),
this results in first stage having SCF_COMPARE_AND_WRITE_POST
set, which incorrectly falls through into second stage CAW
processing code, eventually triggering a NULL pointer
dereference due to use after free.

To address this bug, pass in a new *post_ret parameter into
se_cmd->transport_complete_callback(), and depend upon this
value instead of ->se_cmd_flags to determine when to return
or fall through into ->queue_status() code for CAW.

Cc: Sagi Grimberg 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Jiri Slaby

iscsi-target: Fix potential dead-lock during node acl delete

2016-02-24T09:23:27+00:00

commit 26a99c19f810b2593410899a5b304b21b47428a6 upstream.

This patch is a iscsi-target specific bug-fix for a dead-lock
that can occur during explicit struct se_node_acl->acl_group
se_session deletion via configfs rmdir(2), when iscsi-target
time2retain timer is still active.

It changes iscsi-target to obtain se_portal_group->session_lock
internally using spin_in_locked() to check for the specific
se_node_acl configfs shutdown rmdir(2) case.

Note this patch is intended for stable, and the subsequent
v4.5-rc patch converts target_core_tpg.c to use proper
se_sess->sess_kref reference counting for both se_node_acl
deletion + se_node_acl->queue_depth se_session restart.

Reported-by:: Sagi Grimberg 
Cc: Christoph Hellwig 
Cc: Hannes Reinecke 
Cc: Andy Grover 
Cc: Mike Christie 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Jiri Slaby

iscsi-target: Fix rx_login_comp hang after login failure

2016-02-24T09:23:25+00:00

commit ca82c2bded29b38d36140bfa1e76a7bbfcade390 upstream.

This patch addresses a case where iscsi_target_do_tx_login_io()
fails sending the last login response PDU, after the RX/TX
threads have already been started.

The case centers around iscsi_target_rx_thread() not invoking
allow_signal(SIGINT) before the send_sig(SIGINT, ...) occurs
from the failure path, resulting in RX thread hanging
indefinately on iscsi_conn->rx_login_comp.

Note this bug is a regression introduced by:

  commit e54198657b65625085834847ab6271087323ffea
  Author: Nicholas Bellinger 
  Date:   Wed Jul 22 23:14:19 2015 -0700

      iscsi-target: Fix iscsit_start_kthreads failure OOPs

To address this bug, complete ->rx_login_complete for good
measure in the failure path, and immediately return from
RX thread context if connection state did not actually reach
full feature phase (TARG_CONN_STATE_LOGGED_IN).

Cc: Sagi Grimberg 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Jiri Slaby