kernel/linux.git/drivers/target, branch v3.18.100

target: Avoid early CMD_T_PRE_EXECUTE failures during ABORT_TASK

2018-01-17T08:29:31+00:00

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

iscsi-target: Make TASK_REASSIGN use proper se_cmd->cmd_kref

2018-01-17T08:29:31+00:00

commit ae072726f6109bb1c94841d6fb3a82dde298ea85 upstream. Since commit 59b6986dbf fixed a potential NULL pointer dereference by allocating a se_tmr_req for ISCSI_TM_FUNC_TASK_REASSIGN, the se_tmr_req is currently leaked by iscsit_free_cmd() because no iscsi_cmd->se_cmd.se_tfo was associated. To address this, treat ISCSI_TM_FUNC_TASK_REASSIGN like any other TMR and call transport_init_se_cmd() + target_get_sess_cmd() to setup iscsi_cmd->se_cmd.se_tfo with se_cmd->cmd_kref of 2. This will ensure normal release operation once se_cmd->cmd_kref reaches zero and target_release_cmd_kref() is invoked, se_tmr_req will be released via existing target_free_cmd_mem() and core_tmr_release_req() 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/file: Do not return error for UNMAP if length is zero

2017-12-20T09:01:32+00:00

[ Upstream commit 594e25e73440863981032d76c9b1e33409ceff6e ] The function fd_execute_unmap() in target_core_file.c calles ret = file->f_op->fallocate(file, mode, pos, len); Some filesystems implement fallocate() to return error if length is zero (e.g. btrfs) but according to SCSI Block Commands spec UNMAP should return success for zero length. Signed-off-by: Jiang Yi Signed-off-by: Nicholas Bellinger Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

target:fix condition return in core_pr_dump_initiator_port()

2017-12-20T09:01:32+00:00

[ Upstream commit 24528f089d0a444070aa4f715ace537e8d6bf168 ] When is pr_reg->isid_present_at_reg is false,this function should return. This fixes a regression originally introduced by: commit d2843c173ee53cf4c12e7dfedc069a5bc76f0ac5 Author: Andy Grover Date: Thu May 16 10:40:55 2013 -0700 target: Alter core_pr_dump_initiator_port for ease of use Signed-off-by: tangwenji Signed-off-by: Nicholas Bellinger Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

iscsi-target: fix memory leak in lio_target_tiqn_addtpg()

2017-12-20T09:01:32+00:00

[ Upstream commit 12d5a43b2dffb6cd28062b4e19024f7982393288 ] tpg must free when call core_tpg_register() return fail Signed-off-by: tangwenji Signed-off-by: Nicholas Bellinger Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

target/iscsi: Fix a race condition in iscsit_add_reject_from_cmd()

2017-12-20T09:01:32+00:00

[ Upstream commit cfe2b621bb18d86e93271febf8c6e37622da2d14 ] Avoid that cmd->se_cmd.se_tfo is read after a command has already been freed. Signed-off-by: Bart Van Assche Cc: Christoph Hellwig Cc: Mike Christie Reviewed-by: Hannes Reinecke Signed-off-by: Nicholas Bellinger Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

target: Use system workqueue for ALUA transitions

2017-12-20T09:01:31+00:00

[ Upstream commit 207ee84133c00a8a2a5bdec94df4a5b37d78881c ] If tcmu-runner is processing a STPG and needs to change the kernel's ALUA state then we cannot use the same work queue for task management requests and ALUA transitions, because we could deadlock. The problem occurs when a STPG times out before tcmu-runner is able to call into target_tg_pt_gp_alua_access_state_store-> core_alua_do_port_transition -> core_alua_do_transition_tg_pt -> queue_work. In this case, the tmr is on the work queue waiting for the STPG to complete, but the STPG transition is now queued behind the waiting tmr. Note: This bug will also be fixed by this patch: http://www.spinics.net/lists/target-devel/msg14560.html which switches the tmr code to use the system workqueues. For both, I am not sure if we need a dedicated workqueue since it is not a performance path and I do not think we need WQ_MEM_RECLAIM to make forward progress to free up memory like the block layer does. Signed-off-by: Mike Christie Signed-off-by: Nicholas Bellinger Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

iscsi-target: Fix non-immediate TMR reference leak

2017-11-30T08:35:51+00:00

commit 3fc9fb13a4b2576aeab86c62fd64eb29ab68659c upstream. This patch fixes a se_cmd->cmd_kref reference leak that can occur when a non immediate TMR is proceeded our of command sequence number order, and CMDSN_LOWER_THAN_EXP is returned by iscsit_sequence_cmd(). To address this bug, call target_put_sess_cmd() during this special case following what iscsit_process_scsi_cmd() does upon CMDSN_LOWER_THAN_EXP. Cc: Mike Christie Cc: Hannes Reinecke Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman

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

2017-11-21T08:01:04+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

target/iscsi: Fix iSCSI task reassignment handling

2017-11-18T10:06:31+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