user/sven/linux.git/drivers/target, branch v4.9.16

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

2017-03-15T02:02:46Z

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

2017-02-14T23:25:37Z

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

2017-02-14T23:25:36Z

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

2017-02-14T23:25:36Z

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

2017-02-14T23:25:36Z

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

2017-02-14T23:25:36Z

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()

2017-01-12T10:39:30Z

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()

2017-01-12T10:39:30Z

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

target/user: Fix use-after-free of tcmu_cmds if they are expired

2017-01-09T07:32:25Z

commit d0905ca757bc40bd1ebc261a448a521b064777d7 upstream. Don't free the cmd in tcmu_check_expired_cmd, it's still referenced by an entry in our cmd_id->cmd idr. If userspace ever resumes processing, tcmu_handle_completions() will use the now-invalid cmd pointer. Instead, don't free cmd. It will be freed by tcmu_handle_completion() if userspace ever recovers, or tcmu_free_device if not. Reported-by: Bryant G Ly Tested-by: Bryant G Ly Signed-off-by: Andy Grover Signed-off-by: Bart Van Assche Signed-off-by: Greg Kroah-Hartman

iscsi-target: Return error if unable to add network portal

2017-01-09T07:32:21Z

commit 83337e544323a8bd7492994d64af339175ac7107 upstream. If iscsit_tpg_add_network_portal() fails then return error code instead of 0 to user space. If iscsi-target returns 0 then user space keeps on retrying same command infinitely, targetcli or echo hangs till command completes with non zero return value. In some cases it is possible that add network portal command never completes with success even after retrying multiple times, for example - cxgbit_setup_np() always returns -EINVAL if portal IP does not belong to Chelsio adapter interface. Signed-off-by: Varun Prakash Signed-off-by: Bart Van Assche [ bvanassche: Added "Fixes:" and "Cc: stable" tags ] Fixes: commit d4b3fa4b0881 ("iscsi-target: Make iscsi_tpg_np driver show/store use generic code") Signed-off-by: Greg Kroah-Hartman