linux-toradex.git/drivers/target, branch v4.9.20

target: Fix VERIFY_16 handling in sbc_parse_cdb

2017-03-26T11:05:58+00:00

commit 13603685c1f12c67a7a2427f00b63f39a2b6f7c9 upstream.

As reported by Max, the Windows 2008 R2 chkdsk utility expects
VERIFY_16 to be supported, and does not handle the returned
CHECK_CONDITION properly, resulting in an infinite loop.

The kernel will log huge amounts of this error:

kernel: TARGET_CORE[iSCSI]: Unsupported SCSI Opcode 0x8f, sending
CHECK_CONDITION.

Signed-off-by: Max Lohrmann 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

target/pscsi: Fix TYPE_TAPE + TYPE_MEDIMUM_CHANGER export

2017-03-26T11:05:57+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.

Reported-by: Malcolm Haak 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

target: Fix NULL dereference during LUN lookup + active I/O shutdown

2017-03-15T02:02:46+00:00

commit bd4e2d2907fa23a11d46217064ecf80470ddae10 upstream.

When transport_clear_lun_ref() is shutting down a se_lun via
configfs with new I/O in-flight, it's possible to trigger a
NULL pointer dereference in transport_lookup_cmd_lun() due
to the fact percpu_ref_get() doesn't do any __PERCPU_REF_DEAD
checking before incrementing lun->lun_ref.count after
lun->lun_ref has switched to atomic_t mode.

This results in a NULL pointer dereference as LUN shutdown
code in core_tpg_remove_lun() continues running after the
existing ->release() -> core_tpg_lun_ref_release() callback
completes, and clears the RCU protected se_lun->lun_se_dev
pointer.

During the OOPs, the state of lun->lun_ref in the process
which triggered the NULL pointer dereference looks like
the following on v4.1.y stable code:

struct se_lun {
  lun_link_magic = 4294932337,
  lun_status = TRANSPORT_LUN_STATUS_FREE,

  .....

  lun_se_dev = 0x0,
  lun_sep = 0x0,

  .....

  lun_ref = {
    count = {
      counter = 1
    },
    percpu_count_ptr = 3,
    release = 0xffffffffa02fa1e0 ,
    confirm_switch = 0x0,
    force_atomic = false,
    rcu = {
      next = 0xffff88154fa1a5d0,
      func = 0xffffffff8137c4c0 
    }
  }
}

To address this bug, use percpu_ref_tryget_live() to ensure
once __PERCPU_REF_DEAD is visable on all CPUs and ->lun_ref
has switched to atomic_t, all new I/Os will fail to obtain
a new lun->lun_ref reference.

Also use an explicit percpu_ref_kill_and_confirm() callback
to block on ->lun_ref_comp to allow the first stage and
associated RCU grace period to complete, and then block on
->lun_ref_shutdown waiting for the final percpu_ref_put()
to drop the last reference via transport_lun_remove_cmd()
before continuing with core_tpg_remove_lun() shutdown.

Reported-by: Rob Millner 
Tested-by: Rob Millner 
Cc: Rob Millner 
Tested-by: Vaibhav Tandon 
Cc: Vaibhav Tandon 
Tested-by: Bryant G. Ly 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

target: Fix COMPARE_AND_WRITE ref leak for non GOOD status

2017-02-14T23:25:37+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: Greg Kroah-Hartman

target: Fix multi-session dynamic se_node_acl double free OOPs

2017-02-14T23:25:36+00:00

commit 01d4d673558985d9a118e1e05026633c3e2ade9b upstream.

This patch addresses a long-standing bug with multi-session
(eg: iscsi-target + iser-target) se_node_acl dynamic free
withini transport_deregister_session().

This bug is caused when a storage endpoint is configured with
demo-mode (generate_node_acls = 1 + cache_dynamic_acls = 1)
initiators, and initiator login creates a new dynamic node acl
and attaches two sessions to it.

After that, demo-mode for the storage instance is disabled via
configfs (generate_node_acls = 0 + cache_dynamic_acls = 0) and
the existing dynamic acl is never converted to an explicit ACL.

The end result is dynamic acl resources are released twice when
the sessions are shutdown in transport_deregister_session().

If the storage instance is not changed to disable demo-mode,
or the dynamic acl is converted to an explict ACL, or there
is only a single session associated with the dynamic ACL,
the bug is not triggered.

To address this big, move the release of dynamic se_node_acl
memory into target_complete_nacl() so it's only freed once
when se_node_acl->acl_kref reaches zero.

(Drop unnecessary list_del_init usage - HCH)

Reported-by: Rob Millner 
Tested-by: Rob Millner 
Cc: Rob Millner 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

target: Fix early transport_generic_handle_tmr abort scenario

2017-02-14T23:25:36+00:00

commit c54eeffbe9338fa982dc853d816fda9202a13b5a upstream.

This patch fixes a bug where incoming task management requests
can be explicitly aborted during an active LUN_RESET, but who's
struct work_struct are canceled in-flight before execution.

This occurs when core_tmr_drain_tmr_list() invokes cancel_work_sync()
for the incoming se_tmr_req->task_cmd->work, resulting in cmd->work
for target_tmr_work() never getting invoked and the aborted TMR
waiting indefinately within transport_wait_for_tasks().

To address this case, perform a CMD_T_ABORTED check early in
transport_generic_handle_tmr(), and invoke the normal path via
transport_cmd_check_stop_to_fabric() to complete any TMR kthreads
blocked waiting for CMD_T_STOP in transport_wait_for_tasks().

Also, move the TRANSPORT_ISTATE_PROCESSING assignment earlier
into transport_generic_handle_tmr() so the existing check in
core_tmr_drain_tmr_list() avoids attempting abort the incoming
se_tmr_req->task_cmd->work if it has already been queued into
se_device->tmr_wq.

Reported-by: Rob Millner 
Tested-by: Rob Millner 
Cc: Rob Millner 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

target: Use correct SCSI status during EXTENDED_COPY exception

2017-02-14T23:25:36+00:00

commit 0583c261e6325f392c1f7a1b9112e31298e1a4bd upstream.

This patch adds the missing target_complete_cmd() SCSI status
parameter change in target_xcopy_do_work(), that was originally
missing in commit 926317de33.

It correctly propigates up the correct SCSI status during
EXTENDED_COPY exception cases, instead of always using the
hardcoded SAM_STAT_CHECK_CONDITION from original code.

This is required for ESX host environments that expect to
hit SAM_STAT_RESERVATION_CONFLICT for certain scenarios,
and SAM_STAT_CHECK_CONDITION results in non-retriable
status for these cases.

Reported-by: Nixon Vincent 
Tested-by: Nixon Vincent 
Cc: Nixon Vincent 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

target: Don't BUG_ON during NodeACL dynamic -> explicit conversion

2017-02-14T23:25:36+00:00

commit 391e2a6de9781e4906dd7e0b1cc097050bf43e11 upstream.

After the v4.2+ RCU conversion to se_node_acl->lun_entry_hlist,
a BUG_ON() was added in core_enable_device_list_for_node() to
detect when the located orig->se_lun_acl contains an existing
se_lun_acl pointer reference.

However, this scenario can happen when a dynamically generated
NodeACL is being converted to an explicit NodeACL, when the
explicit NodeACL contains a different LUN mapping than the
default provided by the WWN endpoint.

So instead of triggering BUG_ON(), go ahead and fail instead
following the original pre RCU conversion logic.

Reported-by: Benjamin ESTRABAUD 
Cc: Benjamin ESTRABAUD 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

sbp-target: Fix second argument of percpu_ida_alloc()

2017-01-12T10:39:30+00:00

commit 8456066a57940b3884aa080c58b166567dc9de39 upstream.

Pass a task state as second argument to percpu_ida_alloc().

Fixes: commit 5a3ee221b543 ("sbp-target: Conversion to percpu_ida tag pre-allocation")
Signed-off-by: Bart Van Assche 
Cc: Chris Boot 
Signed-off-by: Greg Kroah-Hartman

target/iscsi: Fix double free in lio_target_tiqn_addtpg()

2017-01-12T10:39:30+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: Greg Kroah-Hartman