user/sven/linux.git/include/target, branch v4.9.128

target: Avoid early CMD_T_PRE_EXECUTE failures during ABORT_TASK

2018-01-17T08:38:54Z

commit 1c21a48055a67ceb693e9c2587824a8de60a217c upstream. This patch fixes bug where early se_cmd exceptions that occur before backend execution can result in use-after-free if/when a subsequent ABORT_TASK occurs for the same tag. Since an early se_cmd exception will have had se_cmd added to se_session->sess_cmd_list via target_get_sess_cmd(), it will not have CMD_T_COMPLETE set by the usual target_complete_cmd() backend completion path. This causes a subsequent ABORT_TASK + __target_check_io_state() to signal ABORT_TASK should proceed. As core_tmr_abort_task() executes, it will bring the outstanding se_cmd->cmd_kref count down to zero releasing se_cmd, after se_cmd has already been queued with error status into fabric driver response path code. To address this bug, introduce a CMD_T_PRE_EXECUTE bit that is set at target_get_sess_cmd() time, and cleared immediately before backend driver dispatch in target_execute_cmd() once CMD_T_ACTIVE is set. Then, check CMD_T_PRE_EXECUTE within __target_check_io_state() to determine when an early exception has occured, and avoid aborting this se_cmd since it will have already been queued into fabric driver response path code. Reported-by: Donald White Cc: Donald White Cc: Mike Christie Cc: Hannes Reinecke Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman

target: fix ALUA transition timeout handling

2017-12-20T09:07:26Z

[ Upstream commit d7175373f2745ed4abe5b388d5aabd06304f801e ] The implicit transition time tells initiators the min time to wait before timing out a transition. We currently schedule the transition to occur in tg_pt_gp_implicit_trans_secs seconds so there is no room for delays. If core_alua_do_transition_tg_pt_work->core_alua_update_tpg_primary_metadata needs to write out info to a remote file, then the initiator can easily time out the operation. Signed-off-by: Mike Christie Signed-off-by: Nicholas Bellinger Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

target/iscsi: Fix iSCSI task reassignment handling

2017-11-18T10:22:25Z

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

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

2017-08-16T20:43:16Z

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 initial login PDU asynchronous socket close OOPs

2017-08-11T15:49:31Z

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: Add login_keys_workaround attribute for non RFC initiators

2017-07-27T22:07:59Z

commit 138d351eefb727ab9e41a3dc5f112ceb4f6e59f2 upstream. This patch re-introduces part of a long standing login workaround that was recently dropped by: commit 1c99de981f30b3e7868b8d20ce5479fa1c0fea46 Author: Nicholas Bellinger Date: Sun Apr 2 13:36:44 2017 -0700 iscsi-target: Drop work-around for legacy GlobalSAN initiator Namely, the workaround for FirstBurstLength ended up being required by Mellanox Flexboot PXE boot ROMs as reported by Robert. So this patch re-adds the work-around for FirstBurstLength within iscsi_check_proposer_for_optional_reply(), and makes the key optional to respond when the initiator does not propose, nor respond to it. Also as requested by Arun, this patch introduces a new TPG attribute named 'login_keys_workaround' that controls the use of both the FirstBurstLength workaround, as well as the two other existing workarounds for gPXE iSCSI boot client. By default, the workaround is enabled with login_keys_workaround=1, since Mellanox FlexBoot requires it, and Arun has verified the Qlogic MSFT initiator already proposes FirstBurstLength, so it's uneffected by this re-adding this part of the original work-around. Reported-by: Robert LeBlanc Cc: Robert LeBlanc Reviewed-by: Arun Easi Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman

target: Avoid mappedlun symlink creation during lun shutdown

2017-04-21T07:31:21Z

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

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 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: Make EXTENDED_COPY 0xe4 failure return COPY TARGET DEVICE NOT REACHABLE

2016-10-20T04:22:32Z

This patch addresses a bug where EXTENDED_COPY across multiple LUNs results in a CHECK_CONDITION when the source + destination are not located on the same physical node. ESX Host environments expect sense COPY_ABORTED w/ COPY TARGET DEVICE NOT REACHABLE to be returned when this occurs, in order to signal fallback to local copy method. As described in section 6.3.3 of spc4r22: "If it is not possible to complete processing of a segment because the copy manager is unable to establish communications with a copy target device, because the copy target device does not respond to INQUIRY, or because the data returned in response to INQUIRY indicates an unsupported logical unit, then the EXTENDED COPY command shall be terminated with CHECK CONDITION status, with the sense key set to COPY ABORTED, and the additional sense code set to COPY TARGET DEVICE NOT REACHABLE." Tested on v4.1.y with ESX v5.5u2+ with BlockCopy across multiple nodes. Reported-by: Nixon Vincent Tested-by: Nixon Vincent Cc: Nixon Vincent Tested-by: Dinesh Israni Signed-off-by: Dinesh Israni Cc: Dinesh Israni Cc: stable@vger.kernel.org # 3.14+ Signed-off-by: Nicholas Bellinger