Hou Pu a5bfcf2455 scsi: target: iscsi: Fix hang in iscsit_access_np() when getting tpg->np_login_sem ... commit ed43ffea78 upstream. The iSCSI target login thread might get stuck with the following stack: cat /proc/`pidof iscsi_np`/stack [<0>] down_interruptible+0x42/0x50 [<0>] iscsit_access_np+0xe3/0x167 [<0>] iscsi_target_locate_portal+0x695/0x8ac [<0>] __iscsi_target_login_thread+0x855/0xb82 [<0>] iscsi_target_login_thread+0x2f/0x5a [<0>] kthread+0xfa/0x130 [<0>] ret_from_fork+0x1f/0x30 This can be reproduced via the following steps: 1. Initiator A tries to log in to iqn1-tpg1 on port 3260. After finishing PDU exchange in the login thread and before the negotiation is finished the the network link goes down. At this point A has not finished login and tpg->np_login_sem is held. 2. Initiator B tries to log in to iqn2-tpg1 on port 3260. After finishing PDU exchange in the login thread the target expects to process remaining login PDUs in workqueue context. 3. Initiator A' tries to log in to iqn1-tpg1 on port 3260 from a new socket. A' will wait for tpg->np_login_sem with np->np_login_timer loaded to wait for at most 15 seconds. The lock is held by A so A' eventually times out. 4. Before A' got timeout initiator B gets negotiation failed and calls iscsi_target_login_drop()->iscsi_target_login_sess_out(). The np->np_login_timer is canceled and initiator A' will hang forever. Because A' is now in the login thread, no new login requests can be serviced. Fix this by moving iscsi_stop_login_thread_timer() out of iscsi_target_login_sess_out(). Also remove iscsi_np parameter from iscsi_target_login_sess_out(). Link: https://lore.kernel.org/r/20200729130343.24976-1-houpu@bytedance.com Cc: stable@vger.kernel.org Reviewed-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Hou Pu <houpu@bytedance.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2020-09-17 13:47:53 +02:00
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cxgbit	…
Kconfig	…
Makefile	…
iscsi_target.c	scsi: target: iscsi: Fix data digest calculation	2020-09-17 13:47:52 +02:00
iscsi_target.h	scsi: target: remove boilerplate code	2020-04-21 09:05:04 +02:00
iscsi_target_auth.c	…
iscsi_target_auth.h	…
iscsi_target_configfs.c	scsi: target: fix hang when multiple threads try to destroy the same iscsi session	2020-04-21 09:05:04 +02:00
iscsi_target_datain_values.c	…
iscsi_target_datain_values.h	…
iscsi_target_device.c	…
iscsi_target_device.h	…
iscsi_target_erl0.c	…
iscsi_target_erl0.h	…
iscsi_target_erl1.c	…
iscsi_target_erl1.h	…
iscsi_target_erl2.c	…
iscsi_target_erl2.h	…
iscsi_target_login.c	scsi: target: iscsi: Fix hang in iscsit_access_np() when getting tpg->np_login_sem	2020-09-17 13:47:53 +02:00
iscsi_target_login.h	scsi: target: iscsi: Fix hang in iscsit_access_np() when getting tpg->np_login_sem	2020-09-17 13:47:53 +02:00
iscsi_target_nego.c	scsi: target: iscsi: Fix hang in iscsit_access_np() when getting tpg->np_login_sem	2020-09-17 13:47:53 +02:00
iscsi_target_nego.h	…
iscsi_target_nodeattrib.c	…
iscsi_target_nodeattrib.h	…
iscsi_target_parameters.c	…
iscsi_target_parameters.h	…
iscsi_target_seq_pdu_list.c	…
iscsi_target_seq_pdu_list.h	…
iscsi_target_stat.c	…
iscsi_target_tmr.c	…
iscsi_target_tmr.h	…
iscsi_target_tpg.c	…
iscsi_target_tpg.h	…
iscsi_target_transport.c	…
iscsi_target_util.c	…
iscsi_target_util.h	…