kernel/git/stable/linux.git/drivers/target/iscsi, branch linux-4.4.y

scsi: target: iscsi: Fix cmd abort fabric stop race

2020-12-02T07:29:28+00:00

[ Upstream commit f36199355c64a39fe82cfddc7623d827c7e050da ] Maurizio found a race where the abort and cmd stop paths can race as follows: 1. thread1 runs iscsit_release_commands_from_conn and sets CMD_T_FABRIC_STOP. 2. thread2 runs iscsit_aborted_task and then does __iscsit_free_cmd. It then returns from the aborted_task callout and we finish target_handle_abort and do: target_handle_abort -> transport_cmd_check_stop_to_fabric -> lio_check_stop_free -> target_put_sess_cmd The cmd is now freed. 3. thread1 now finishes iscsit_release_commands_from_conn and runs iscsit_free_cmd while accessing a command we just released. In __target_check_io_state we check for CMD_T_FABRIC_STOP and set the CMD_T_ABORTED if the driver is not cleaning up the cmd because of a session shutdown. However, iscsit_release_commands_from_conn only sets the CMD_T_FABRIC_STOP and does not check to see if the abort path has claimed completion ownership of the command. This adds a check in iscsit_release_commands_from_conn so only the abort or fabric stop path cleanup the command. Link: https://lore.kernel.org/r/1605318378-9269-1-git-send-email-michael.christie@oracle.com Reported-by: Maurizio Lombardi Reviewed-by: Maurizio Lombardi Signed-off-by: Mike Christie Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: target: iscsi: Fix hang in iscsit_access_np() when getting tpg->np_login_sem

2020-09-23T06:44:25+00:00

commit ed43ffea78dcc97db3f561da834f1a49c8961e33 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 Signed-off-by: Hou Pu Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman

scsi: Revert "target: iscsi: Wait for all commands to finish before freeing a session"

2020-02-28T14:39:17+00:00

commit 807b9515b7d044cf77df31f1af9d842a76ecd5cb upstream. Since commit e9d3009cb936 introduced a regression and since the fix for that regression was not perfect, revert this commit. Link: https://marc.info/?l=target-devel&m=158157054906195 Cc: Rahul Kundu Cc: Mike Marciniszyn Cc: Sagi Grimberg Reported-by: Dakshaja Uppalapati Fixes: e9d3009cb936 ("scsi: target: iscsi: Wait for all commands to finish before freeing a session") Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman

scsi: Revert "RDMA/isert: Fix a recently introduced regression related to logout"

2020-02-28T14:39:17+00:00

commit 76261ada16dcc3be610396a46d35acc3efbda682 upstream. Since commit 04060db41178 introduces soft lockups when toggling network interfaces, revert it. Link: https://marc.info/?l=target-devel&m=158157054906196 Cc: Rahul Kundu Cc: Mike Marciniszyn Cc: Sagi Grimberg Reported-by: Dakshaja Uppalapati Fixes: 04060db41178 ("scsi: RDMA/isert: Fix a recently introduced regression related to logout") Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman

scsi: RDMA/isert: Fix a recently introduced regression related to logout

2020-01-29T09:21:52+00:00

commit 04060db41178c7c244f2c7dcd913e7fd331de915 upstream. iscsit_close_connection() calls isert_wait_conn(). Due to commit e9d3009cb936 both functions call target_wait_for_sess_cmds() although that last function should be called only once. Fix this by removing the target_wait_for_sess_cmds() call from isert_wait_conn() and by only calling isert_wait_conn() after target_wait_for_sess_cmds(). Fixes: e9d3009cb936 ("scsi: target: iscsi: Wait for all commands to finish before freeing a session"). Link: https://lore.kernel.org/r/20200116044737.19507-1-bvanassche@acm.org Reported-by: Rahul Kundu Signed-off-by: Bart Van Assche Tested-by: Mike Marciniszyn Acked-by: Sagi Grimberg Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman

scsi: target: iscsi: Wait for all commands to finish before freeing a session

2020-01-04T12:34:36+00:00

[ Upstream commit e9d3009cb936bd0faf0719f68d98ad8afb1e613b ] The iSCSI target driver is the only target driver that does not wait for ongoing commands to finish before freeing a session. Make the iSCSI target driver wait for ongoing commands to finish before freeing a session. This patch fixes the following KASAN complaint: BUG: KASAN: use-after-free in __lock_acquire+0xb1a/0x2710 Read of size 8 at addr ffff8881154eca70 by task kworker/0:2/247 CPU: 0 PID: 247 Comm: kworker/0:2 Not tainted 5.4.0-rc1-dbg+ #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Workqueue: target_completion target_complete_ok_work [target_core_mod] Call Trace: dump_stack+0x8a/0xd6 print_address_description.constprop.0+0x40/0x60 __kasan_report.cold+0x1b/0x33 kasan_report+0x16/0x20 __asan_load8+0x58/0x90 __lock_acquire+0xb1a/0x2710 lock_acquire+0xd3/0x200 _raw_spin_lock_irqsave+0x43/0x60 target_release_cmd_kref+0x162/0x7f0 [target_core_mod] target_put_sess_cmd+0x2e/0x40 [target_core_mod] lio_check_stop_free+0x12/0x20 [iscsi_target_mod] transport_cmd_check_stop_to_fabric+0xd8/0xe0 [target_core_mod] target_complete_ok_work+0x1b0/0x790 [target_core_mod] process_one_work+0x549/0xa40 worker_thread+0x7a/0x5d0 kthread+0x1bc/0x210 ret_from_fork+0x24/0x30 Allocated by task 889: save_stack+0x23/0x90 __kasan_kmalloc.constprop.0+0xcf/0xe0 kasan_slab_alloc+0x12/0x20 kmem_cache_alloc+0xf6/0x360 transport_alloc_session+0x29/0x80 [target_core_mod] iscsi_target_login_thread+0xcd6/0x18f0 [iscsi_target_mod] kthread+0x1bc/0x210 ret_from_fork+0x24/0x30 Freed by task 1025: save_stack+0x23/0x90 __kasan_slab_free+0x13a/0x190 kasan_slab_free+0x12/0x20 kmem_cache_free+0x146/0x400 transport_free_session+0x179/0x2f0 [target_core_mod] transport_deregister_session+0x130/0x180 [target_core_mod] iscsit_close_session+0x12c/0x350 [iscsi_target_mod] iscsit_logout_post_handler+0x136/0x380 [iscsi_target_mod] iscsit_response_queue+0x8de/0xbe0 [iscsi_target_mod] iscsi_target_tx_thread+0x27f/0x370 [iscsi_target_mod] kthread+0x1bc/0x210 ret_from_fork+0x24/0x30 The buggy address belongs to the object at ffff8881154ec9c0 which belongs to the cache se_sess_cache of size 352 The buggy address is located 176 bytes inside of 352-byte region [ffff8881154ec9c0, ffff8881154ecb20) The buggy address belongs to the page: page:ffffea0004553b00 refcount:1 mapcount:0 mapping:ffff888101755400 index:0x0 compound_mapcount: 0 flags: 0x2fff000000010200(slab|head) raw: 2fff000000010200 dead000000000100 dead000000000122 ffff888101755400 raw: 0000000000000000 0000000080130013 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881154ec900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8881154ec980: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb >ffff8881154eca00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881154eca80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881154ecb00: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc Cc: Mike Christie Link: https://lore.kernel.org/r/20191113220508.198257-3-bvanassche@acm.org Reviewed-by: Roman Bolshakov Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: target: compare full CHAP_A Algorithm strings

2020-01-04T12:34:25+00:00

[ Upstream commit 9cef2a7955f2754257a7cddedec16edae7b587d0 ] RFC 2307 states: For CHAP [RFC1994], in the first step, the initiator MUST send: CHAP_A= Where A1,A2... are proposed algorithms, in order of preference. ... For the Algorithm, as stated in [RFC1994], one value is required to be implemented: 5 (CHAP with MD5) LIO currently checks for this value by only comparing a single byte in the tokenized Algorithm string, which means that any value starting with a '5' (e.g. "55") is interpreted as "CHAP with MD5". Fix this by comparing the entire tokenized string. Reviewed-by: Lee Duncan Reviewed-by: Mike Christie Signed-off-by: David Disseldorp Link: https://lore.kernel.org/r/20190912095547.22427-2-ddiss@suse.de Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: target/iscsi: Avoid iscsit_release_commands_from_conn() deadlock

2019-03-23T07:44:35+00:00

commit 32e36bfbcf31452a854263e7c7f32fbefc4b44d8 upstream. When using SCSI passthrough in combination with the iSCSI target driver then cmd->t_state_lock may be obtained from interrupt context. Hence, all code that obtains cmd->t_state_lock from thread context must disable interrupts first. This patch avoids that lockdep reports the following: WARNING: inconsistent lock state 4.18.0-dbg+ #1 Not tainted -------------------------------- inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage. iscsi_ttx/1800 [HC1[1]:SC0[2]:HE0:SE0] takes: 000000006e7b0ceb (&(&cmd->t_state_lock)->rlock){?...}, at: target_complete_cmd+0x47/0x2c0 [target_core_mod] {HARDIRQ-ON-W} state was registered at: lock_acquire+0xd2/0x260 _raw_spin_lock+0x32/0x50 iscsit_close_connection+0x97e/0x1020 [iscsi_target_mod] iscsit_take_action_for_connection_exit+0x108/0x200 [iscsi_target_mod] iscsi_target_rx_thread+0x180/0x190 [iscsi_target_mod] kthread+0x1cf/0x1f0 ret_from_fork+0x24/0x30 irq event stamp: 1281 hardirqs last enabled at (1279): [] __local_bh_enable_ip+0xa9/0x160 hardirqs last disabled at (1281): [] interrupt_entry+0xb5/0xd0 softirqs last enabled at (1278): [] lock_sock_nested+0x51/0xc0 softirqs last disabled at (1280): [] ip6_finish_output2+0x124/0xe40 [ipv6] other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&cmd->t_state_lock)->rlock); lock(&(&cmd->t_state_lock)->rlock);

scsi: target: iscsi: Use bin2hex instead of a re-implementation

2018-10-10T06:52:08+00:00

commit 8c39e2699f8acb2e29782a834e56306da24937fe upstream. Signed-off-by: Vincent Pelletier Reviewed-by: Mike Christie Signed-off-by: Martin K. Petersen [plr.vincent@gmail.com: hunk context change for 4.4 and 4.9, no code change] Signed-off-by: Greg Kroah-Hartman

scsi: target/iscsi: Make iscsit_ta_authentication() respect the output buffer size

2018-10-10T06:52:05+00:00

[ Upstream commit 35bea5c84fd13c643cce63f0b5cd4b148f8c901d ] Fixes: e48354ce078c ("iscsi-target: Add iSCSI fabric support for target v4.1") Signed-off-by: Bart Van Assche Reviewed-by: Mike Christie Cc: Mike Christie Cc: Christoph Hellwig Cc: Hannes Reinecke Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman