user/sven/linux.git/drivers/target, branch v3.18.32

target: Fix target_release_cmd_kref shutdown comp leak

2016-04-18T12:49:37Z

[ Upstream commit 5e47f1985d7107331c3f64fb3ec83d66fd73577e ] 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. Reported-by: Himanshu Madhani Tested-by: Himanshu Madhani Signed-off-by: Himanshu Madhani Cc: stable@vger.kernel.org Signed-off-by: Nicholas Bellinger Signed-off-by: Sasha Levin

target: Drop incorrect ABORT_TASK put for completed commands

2016-03-22T15:11:11Z

[ Upstream commit 7f54ab5ff52fb0b91569bc69c4a6bc5cac1b768d ] This patch fixes a recent ABORT_TASK regression associated with commit febe562c, where a left-over target_put_sess_cmd() would still be called when __target_check_io_state() detected a command has already been completed, and explicit ABORT must be avoided. Note commit febe562c dropped the local kref_get_unless_zero() check in core_tmr_abort_task(), but did not drop this extra corresponding target_put_sess_cmd() in the failure path. So go ahead and drop this now bogus target_put_sess_cmd(), and avoid this potential use-after-free. Reported-by: Dan Lane Cc: Quinn Tran Cc: Himanshu Madhani Cc: Sagi Grimberg Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Andy Grover Cc: Mike Christie Cc: stable@vger.kernel.org # 3.14+ Signed-off-by: Nicholas Bellinger Signed-off-by: Sasha Levin

target: Fix race with SCF_SEND_DELAYED_TAS handling

2016-03-06T03:13:45Z

commit 310d3d314be7f0a84011ebdc4bdccbcae9755a87 upstream. This patch fixes a race between setting of SCF_SEND_DELAYED_TAS in transport_send_task_abort(), and check of the same bit in transport_check_aborted_status(). It adds a __transport_check_aborted_status() version that is used by target_execute_cmd() when se_cmd->t_state_lock is held, and a transport_check_aborted_status() wrapper for all other existing callers. Also, it handles the case where the check happens before transport_send_task_abort() gets called. For this, go ahead and set SCF_SEND_DELAYED_TAS early when necessary, and have transport_send_task_abort() send the abort. Cc: Quinn Tran Cc: Himanshu Madhani Cc: Sagi Grimberg Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Andy Grover Cc: Mike Christie Signed-off-by: Nicholas Bellinger Signed-off-by: Sasha Levin

target: Fix remote-port TMR ABORT + se_cmd fabric stop

2016-03-06T03:13:44Z

commit 0f4a943168f31d29a1701908931acaba518b131a upstream. To address the bug where fabric driver level shutdown of se_cmd occurs at the same time when TMR CMD_T_ABORTED is happening resulting in a -1 ->cmd_kref, this patch adds a CMD_T_FABRIC_STOP bit that is used to determine when TMR + driver I_T nexus shutdown is happening concurrently. It changes target_sess_cmd_list_set_waiting() to obtain se_cmd->cmd_kref + set CMD_T_FABRIC_STOP, and drop local reference in target_wait_for_sess_cmds() and invoke extra target_put_sess_cmd() during Task Aborted Status (TAS) when necessary. Also, it adds a new target_wait_free_cmd() wrapper around transport_wait_for_tasks() for the special case within transport_generic_free_cmd() to set CMD_T_FABRIC_STOP, and is now aware of CMD_T_ABORTED + CMD_T_TAS status bits to know when an extra transport_put_cmd() during TAS is required. Note transport_generic_free_cmd() is expected to block on cmd->cmd_wait_comp in order to follow what iscsi-target expects during iscsi_conn context se_cmd shutdown. Cc: Quinn Tran Cc: Himanshu Madhani Cc: Sagi Grimberg Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Andy Grover Cc: Mike Christie Signed-off-by: Nicholas Bellinger Signed-off-by: Sasha Levin

target: Fix TAS handling for multi-session se_node_acls

2016-03-06T03:13:43Z

commit ebde1ca5a908b10312db4ecd7553e3ba039319ab upstream. This patch fixes a bug in TMR task aborted status (TAS) handling when multiple sessions are connected to the same target WWPN endpoint and se_node_acl descriptor, resulting in TASK_ABORTED status to not be generated for aborted se_cmds on the remote port. This is due to core_tmr_handle_tas_abort() incorrectly comparing se_node_acl instead of se_session, for which the multi-session case is expected to be sharing the same se_node_acl. Instead, go ahead and update core_tmr_handle_tas_abort() to compare tmr_sess + cmd->se_sess in order to determine if the LUN_RESET was received on a different I_T nexus, and TASK_ABORTED status response needs to be generated. Reviewed-by: Christoph Hellwig Cc: Quinn Tran Cc: Himanshu Madhani Cc: Sagi Grimberg Cc: Hannes Reinecke Cc: Andy Grover Cc: Mike Christie Signed-off-by: Nicholas Bellinger Signed-off-by: Sasha Levin

target: Fix LUN_RESET active I/O handling for ACK_KREF

2016-03-06T03:13:43Z

commit febe562c20dfa8f33bee7d419c6b517986a5aa33 upstream. This patch fixes a NULL pointer se_cmd->cmd_kref < 0 refcount bug during TMR LUN_RESET with active se_cmd I/O, that can be triggered during se_cmd descriptor shutdown + release via core_tmr_drain_state_list() code. To address this bug, add common __target_check_io_state() helper for ABORT_TASK + LUN_RESET w/ CMD_T_COMPLETE checking, and set CMD_T_ABORTED + obtain ->cmd_kref for both cases ahead of last target_put_sess_cmd() after TFO->aborted_task() -> transport_cmd_finish_abort() callback has completed. It also introduces SCF_ACK_KREF to determine when transport_cmd_finish_abort() needs to drop the second extra reference, ahead of calling target_put_sess_cmd() for the final kref_put(&se_cmd->cmd_kref). It also updates transport_cmd_check_stop() to avoid holding se_cmd->t_state_lock while dropping se_cmd device state via target_remove_from_state_list(), now that core_tmr_drain_state_list() is holding the se_device lock while checking se_cmd state from within TMR logic. Finally, move transport_put_cmd() release of SGL + TMR + extended CDB memory into target_free_cmd_mem() in order to avoid potential resource leaks in TMR ABORT_TASK + LUN_RESET code-paths. Also update target_release_cmd_kref() accordingly. Reviewed-by: Quinn Tran Cc: Himanshu Madhani Cc: Sagi Grimberg Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Andy Grover Cc: Mike Christie Signed-off-by: Nicholas Bellinger Signed-off-by: Sasha Levin

target: fix COMPARE_AND_WRITE non zero SGL offset data corruption

2016-03-06T03:13:43Z

[ Upstream commit d94e5a61357a04938ce14d6033b4d33a3c5fd780 ] 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: Sasha Levin

target: Fix race for SCF_COMPARE_AND_WRITE_POST checking

2016-03-06T03:13:43Z

[ Upstream commit 057085e522f8bf94c2e691a5b76880f68060f8ba ] 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: Sasha Levin

iscsi-target: Fix rx_login_comp hang after login failure

2016-03-06T03:13:42Z

[ Upstream commit ca82c2bded29b38d36140bfa1e76a7bbfcade390 ] 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 Cc: # v3.10+ Signed-off-by: Nicholas Bellinger Signed-off-by: Sasha Levin

target: Fix LUN_RESET active TMR descriptor handling

2016-03-02T20:18:56Z

[ Upstream commit a6d9bb1c9605cd4f44e2d8290dc4d0e88f20292d ] This patch fixes a NULL pointer se_cmd->cmd_kref < 0 refcount bug during TMR LUN_RESET with active TMRs, triggered during se_cmd + se_tmr_req descriptor shutdown + release via core_tmr_drain_tmr_list(). To address this bug, go ahead and obtain a local kref_get_unless_zero(&se_cmd->cmd_kref) for active I/O to set CMD_T_ABORTED, and transport_wait_for_tasks() followed by the final target_put_sess_cmd() to drop the local ->cmd_kref. Also add two new checks within target_tmr_work() to avoid CMD_T_ABORTED -> TFO->queue_tm_rsp() callbacks ahead of invoking the backend -> fabric put in transport_cmd_check_stop_to_fabric(). For good measure, also change core_tmr_release_req() to use list_del_init() ahead of se_tmr_req memory free. Reviewed-by: Quinn Tran Cc: Himanshu Madhani Cc: Sagi Grimberg Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Andy Grover Cc: Mike Christie Cc: stable@vger.kernel.org # 3.10+ Signed-off-by: Nicholas Bellinger Signed-off-by: Sasha Levin