kernel.git/drivers/scsi/libiscsi.c, branch linux-4.4.y

scsi: libiscsi: Fix UAF in iscsi_conn_get_param()/iscsi_conn_teardown()

2022-01-11T12:37:11Z

[ Upstream commit 1b8d0300a3e9f216ae4901bab886db7299899ec6 ] |- iscsi_if_destroy_conn |-dev_attr_show |-iscsi_conn_teardown |-spin_lock_bh |-iscsi_sw_tcp_conn_get_param |-kfree(conn->persistent_address) |-iscsi_conn_get_param |-kfree(conn->local_ipaddr) ==>|-read persistent_address ==>|-read local_ipaddr |-spin_unlock_bh When iscsi_conn_teardown() and iscsi_conn_get_param() happen in parallel, a UAF may be triggered. Link: https://lore.kernel.org/r/046ec8a0-ce95-d3fc-3235-666a7c65b224@huawei.com Reported-by: Lu Tixiong Reviewed-by: Mike Christie Reviewed-by: Lee Duncan Signed-off-by: Lixiaokeng Signed-off-by: Linfeilong Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: iscsi: Add iscsi_cls_conn refcount helpers

2021-07-20T14:22:41Z

[ Upstream commit b1d19e8c92cfb0ded180ef3376c20e130414e067 ] There are a couple places where we could free the iscsi_cls_conn while it's still in use. This adds some helpers to get/put a refcount on the struct and converts an exiting user. Subsequent commits will then use the helpers to fix 2 bugs in the eh code. Link: https://lore.kernel.org/r/20210525181821.7617-11-michael.christie@oracle.com Reviewed-by: Lee Duncan Signed-off-by: Mike Christie Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: libiscsi: Fix iscsi_prep_scsi_cmd_pdu() error handling

2021-03-17T15:07:20Z

[ Upstream commit d28d48c699779973ab9a3bd0e5acfa112bd4fdef ] If iscsi_prep_scsi_cmd_pdu() fails we try to add it back to the cmdqueue, but we leave it partially setup. We don't have functions that can undo the pdu and init task setup. We only have cleanup_task which can clean up both parts. So this has us just fail the cmd and go through the standard cleanup routine and then have the SCSI midlayer retry it like is done when it fails in the queuecommand path. Link: https://lore.kernel.org/r/20210207044608.27585-2-michael.christie@oracle.com Reviewed-by: Lee Duncan Signed-off-by: Mike Christie Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: iscsi: Ensure sysfs attributes are limited to PAGE_SIZE

2021-03-07T10:24:22Z

commit ec98ea7070e94cc25a422ec97d1421e28d97b7ee upstream. As the iSCSI parameters are exported back through sysfs, it should be enforcing that they never are more than PAGE_SIZE (which should be more than enough) before accepting updates through netlink. Change all iSCSI sysfs attributes to use sysfs_emit(). Cc: stable@vger.kernel.org Reported-by: Adam Nichols Reviewed-by: Lee Duncan Reviewed-by: Greg Kroah-Hartman Reviewed-by: Mike Christie Signed-off-by: Chris Leech Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman

scsi: libiscsi: Fix NOP race condition

2020-12-02T07:29:28Z

[ Upstream commit fe0a8a95e7134d0b44cd407bc0085b9ba8d8fe31 ] iSCSI NOPs are sometimes "lost", mistakenly sent to the user-land iscsid daemon instead of handled in the kernel, as they should be, resulting in a message from the daemon like: iscsid: Got nop in, but kernel supports nop handling. This can occur because of the new forward- and back-locks, and the fact that an iSCSI NOP response can occur before processing of the NOP send is complete. This can result in "conn->ping_task" being NULL in iscsi_nop_out_rsp(), when the pointer is actually in the process of being set. To work around this, we add a new state to the "ping_task" pointer. In addition to NULL (not assigned) and a pointer (assigned), we add the state "being set", which is signaled with an INVALID pointer (using "-1"). Link: https://lore.kernel.org/r/20201106193317.16993-1-leeman.duncan@gmail.com Reviewed-by: Mike Christie Signed-off-by: Lee Duncan Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: iscsi: Fix a potential deadlock in the timeout handler

2020-05-20T06:11:57Z

commit 5480e299b5ae57956af01d4839c9fc88a465eeab upstream. Some time ago the block layer was modified such that timeout handlers are called from thread context instead of interrupt context. Make it safe to run the iSCSI timeout handler in thread context. This patch fixes the following lockdep complaint: ================================ WARNING: inconsistent lock state 5.5.1-dbg+ #11 Not tainted -------------------------------- inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. kworker/7:1H/206 [HC0[0]:SC0[0]:HE1:SE1] takes: ffff88802d9827e8 (&(&session->frwd_lock)->rlock){+.?.}, at: iscsi_eh_cmd_timed_out+0xa6/0x6d0 [libiscsi] {IN-SOFTIRQ-W} state was registered at: lock_acquire+0x106/0x240 _raw_spin_lock+0x38/0x50 iscsi_check_transport_timeouts+0x3e/0x210 [libiscsi] call_timer_fn+0x132/0x470 __run_timers.part.0+0x39f/0x5b0 run_timer_softirq+0x63/0xc0 __do_softirq+0x12d/0x5fd irq_exit+0xb3/0x110 smp_apic_timer_interrupt+0x131/0x3d0 apic_timer_interrupt+0xf/0x20 default_idle+0x31/0x230 arch_cpu_idle+0x13/0x20 default_idle_call+0x53/0x60 do_idle+0x38a/0x3f0 cpu_startup_entry+0x24/0x30 start_secondary+0x222/0x290 secondary_startup_64+0xa4/0xb0 irq event stamp: 1383705 hardirqs last enabled at (1383705): [] _raw_spin_unlock_irq+0x2c/0x50 hardirqs last disabled at (1383704): [] _raw_spin_lock_irq+0x18/0x50 softirqs last enabled at (1383690): [] iscsi_queuecommand+0x76a/0xa20 [libiscsi] softirqs last disabled at (1383682): [] iscsi_queuecommand+0x118/0xa20 [libiscsi] other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&session->frwd_lock)->rlock); lock(&(&session->frwd_lock)->rlock); *** DEADLOCK *** 2 locks held by kworker/7:1H/206: #0: ffff8880d57bf928 ((wq_completion)kblockd){+.+.}, at: process_one_work+0x472/0xab0 #1: ffff88802b9c7de8 ((work_completion)(&q->timeout_work)){+.+.}, at: process_one_work+0x476/0xab0 stack backtrace: CPU: 7 PID: 206 Comm: kworker/7:1H Not tainted 5.5.1-dbg+ #11 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 Workqueue: kblockd blk_mq_timeout_work Call Trace: dump_stack+0xa5/0xe6 print_usage_bug.cold+0x232/0x23b mark_lock+0x8dc/0xa70 __lock_acquire+0xcea/0x2af0 lock_acquire+0x106/0x240 _raw_spin_lock+0x38/0x50 iscsi_eh_cmd_timed_out+0xa6/0x6d0 [libiscsi] scsi_times_out+0xf4/0x440 [scsi_mod] scsi_timeout+0x1d/0x20 [scsi_mod] blk_mq_check_expired+0x365/0x3a0 bt_iter+0xd6/0xf0 blk_mq_queue_tag_busy_iter+0x3de/0x650 blk_mq_timeout_work+0x1af/0x380 process_one_work+0x56d/0xab0 worker_thread+0x7a/0x5d0 kthread+0x1bc/0x210 ret_from_fork+0x24/0x30 Fixes: 287922eb0b18 ("block: defer timeouts to a workqueue") Cc: Christoph Hellwig Cc: Keith Busch Cc: Lee Duncan Cc: Chris Leech Cc: Link: https://lore.kernel.org/r/20191209173457.187370-1-bvanassche@acm.org Signed-off-by: Bart Van Assche Reviewed-by: Lee Duncan Signed-off-by: Martin K. Petersen Cc: Henri Rosten Signed-off-by: Greg Kroah-Hartman

scsi: libiscsi: Fix race between iscsi_xmit_task and iscsi_complete_task

2019-03-23T07:44:33Z

[ Upstream commit 79edd00dc6a96644d76b4a1cb97d94d49e026768 ] When a target sends Check Condition, whilst initiator is busy xmiting re-queued data, could lead to race between iscsi_complete_task() and iscsi_xmit_task() and eventually crashing with the following kernel backtrace. [3326150.987523] ALERT: BUG: unable to handle kernel NULL pointer dereference at 0000000000000078 [3326150.987549] ALERT: IP: [] iscsi_xmit_task+0x2d/0xc0 [libiscsi] [3326150.987571] WARN: PGD 569c8067 PUD 569c9067 PMD 0 [3326150.987582] WARN: Oops: 0002 [#1] SMP [3326150.987593] WARN: Modules linked in: tun nfsv3 nfs fscache dm_round_robin [3326150.987762] WARN: CPU: 2 PID: 8399 Comm: kworker/u32:1 Tainted: G O 4.4.0+2 #1 [3326150.987774] WARN: Hardware name: Dell Inc. PowerEdge R720/0W7JN5, BIOS 2.5.4 01/22/2016 [3326150.987790] WARN: Workqueue: iscsi_q_13 iscsi_xmitworker [libiscsi] [3326150.987799] WARN: task: ffff8801d50f3800 ti: ffff8801f5458000 task.ti: ffff8801f5458000 [3326150.987810] WARN: RIP: e030:[] [] iscsi_xmit_task+0x2d/0xc0 [libiscsi] [3326150.987825] WARN: RSP: e02b:ffff8801f545bdb0 EFLAGS: 00010246 [3326150.987831] WARN: RAX: 00000000ffffffc3 RBX: ffff880282d2ab20 RCX: ffff88026b6ac480 [3326150.987842] WARN: RDX: 0000000000000000 RSI: 00000000fffffe01 RDI: ffff880282d2ab20 [3326150.987852] WARN: RBP: ffff8801f545bdc8 R08: 0000000000000000 R09: 0000000000000008 [3326150.987862] WARN: R10: 0000000000000000 R11: 000000000000fe88 R12: 0000000000000000 [3326150.987872] WARN: R13: ffff880282d2abe8 R14: ffff880282d2abd8 R15: ffff880282d2ac08 [3326150.987890] WARN: FS: 00007f5a866b4840(0000) GS:ffff88028a640000(0000) knlGS:0000000000000000 [3326150.987900] WARN: CS: e033 DS: 0000 ES: 0000 CR0: 0000000080050033 [3326150.987907] WARN: CR2: 0000000000000078 CR3: 0000000070244000 CR4: 0000000000042660 [3326150.987918] WARN: Stack: [3326150.987924] WARN: ffff880282d2ad58 ffff880282d2ab20 ffff880282d2abe8 ffff8801f545be18 [3326150.987938] WARN: ffffffffa05cea90 ffff880282d2abf8 ffff88026b59cc80 ffff88026b59cc00 [3326150.987951] WARN: ffff88022acf32c0 ffff880289491800 ffff880255a80800 0000000000000400 [3326150.987964] WARN: Call Trace: [3326150.987975] WARN: [] iscsi_xmitworker+0x2f0/0x360 [libiscsi] [3326150.987988] WARN: [] process_one_work+0x1fc/0x3b0 [3326150.987997] WARN: [] worker_thread+0x2a5/0x470 [3326150.988006] WARN: [] ? __schedule+0x648/0x870 [3326150.988015] WARN: [] ? rescuer_thread+0x300/0x300 [3326150.988023] WARN: [] kthread+0xd5/0xe0 [3326150.988031] WARN: [] ? kthread_stop+0x110/0x110 [3326150.988040] WARN: [] ret_from_fork+0x3f/0x70 [3326150.988048] WARN: [] ? kthread_stop+0x110/0x110 [3326150.988127] ALERT: RIP [] iscsi_xmit_task+0x2d/0xc0 [libiscsi] [3326150.988138] WARN: RSP [3326150.988144] WARN: CR2: 0000000000000078 [3326151.020366] WARN: ---[ end trace 1c60974d4678d81b ]--- Commit 6f8830f5bbab ("scsi: libiscsi: add lock around task lists to fix list corruption regression") introduced "taskqueuelock" to fix list corruption during the race, but this wasn't enough. Re-setting of conn->task to NULL, could race with iscsi_xmit_task(). iscsi_complete_task() { .... if (conn->task == task) conn->task = NULL; } conn->task in iscsi_xmit_task() could be NULL and so will be task. __iscsi_get_task(task) will crash (NullPtr de-ref), trying to access refcount. iscsi_xmit_task() { struct iscsi_task *task = conn->task; __iscsi_get_task(task); } This commit will take extra conn->session->back_lock in iscsi_xmit_task() to ensure iscsi_xmit_task() waits for iscsi_complete_task(), if iscsi_complete_task() wins the race. If iscsi_xmit_task() wins the race, iscsi_xmit_task() increments task->refcount (__iscsi_get_task) ensuring iscsi_complete_task() will not iscsi_free_task(). Signed-off-by: Anoob Soman Signed-off-by: Bob Liu Acked-by: Lee Duncan Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: libiscsi: Fix NULL pointer dereference in iscsi_eh_session_reset

2018-12-21T13:09:52Z

[ Upstream commit 5db6dd14b31397e8cccaaddab2ff44ebec1acf25 ] This commit addresses NULL pointer dereference in iscsi_eh_session_reset. Reference should not be made to session->leadconn when session->state is set to ISCSI_STATE_TERMINATE. Signed-off-by: Fred Herard Reviewed-by: Konrad Rzeszutek Wilk Reviewed-by: Lee Duncan Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

scsi: libiscsi: fix possible NULL pointer dereference in case of TMF

2018-09-05T07:18:34Z

[ Upstream commit a17037e7d59075053b522048742a08ac9500bde8 ] In iscsi_check_tmf_restrictions() task->hdr is dereferenced to print the opcode, it is possible that task->hdr is NULL. There are two cases based on opcode argument: 1. ISCSI_OP_SCSI_CMD - In this case alloc_pdu() is called after iscsi_check_tmf_restrictions() iscsi_prep_scsi_cmd_pdu() -> iscsi_check_tmf_restrictions() -> alloc_pdu(). Transport drivers allocate memory for iSCSI hdr in alloc_pdu() and assign it to task->hdr. In case of TMF task->hdr will be NULL resulting in NULL pointer dereference. 2. ISCSI_OP_SCSI_DATA_OUT - In this case transport driver can free the memory for iSCSI hdr after transmitting the pdu so task->hdr can be NULL or invalid. This patch fixes this issue by removing task->hdr->opcode from the printk statement. Signed-off-by: Varun Prakash Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

scsi: libiscsi: Allow sd_shutdown on bad transport

2018-04-13T17:50:13Z

[ Upstream commit d754941225a7dbc61f6dd2173fa9498049f9a7ee ] If, for any reason, userland shuts down iscsi transport interfaces before proper logouts - like when logging in to LUNs manually, without logging out on server shutdown, or when automated scripts can't umount/logout from logged LUNs - kernel will hang forever on its sd_sync_cache() logic, after issuing the SYNCHRONIZE_CACHE cmd to all still existent paths. PID: 1 TASK: ffff8801a69b8000 CPU: 1 COMMAND: "systemd-shutdow" #0 [ffff8801a69c3a30] __schedule at ffffffff8183e9ee #1 [ffff8801a69c3a80] schedule at ffffffff8183f0d5 #2 [ffff8801a69c3a98] schedule_timeout at ffffffff81842199 #3 [ffff8801a69c3b40] io_schedule_timeout at ffffffff8183e604 #4 [ffff8801a69c3b70] wait_for_completion_io_timeout at ffffffff8183fc6c #5 [ffff8801a69c3bd0] blk_execute_rq at ffffffff813cfe10 #6 [ffff8801a69c3c88] scsi_execute at ffffffff815c3fc7 #7 [ffff8801a69c3cc8] scsi_execute_req_flags at ffffffff815c60fe #8 [ffff8801a69c3d30] sd_sync_cache at ffffffff815d37d7 #9 [ffff8801a69c3da8] sd_shutdown at ffffffff815d3c3c This happens because iscsi_eh_cmd_timed_out(), the transport layer timeout helper, would tell the queue timeout function (scsi_times_out) to reset the request timer over and over, until the session state is back to logged in state. Unfortunately, during server shutdown, this might never happen again. Other option would be "not to handle" the issue in the transport layer. That would trigger the error handler logic, which would also need the session state to be logged in again. Best option, for such case, is to tell upper layers that the command was handled during the transport layer error handler helper, marking it as DID_NO_CONNECT, which will allow completion and inform about the problem. After the session was marked as ISCSI_STATE_FAILED, due to the first timeout during the server shutdown phase, all subsequent cmds will fail to be queued, allowing upper logic to fail faster. Signed-off-by: Rafael David Tinoco Reviewed-by: Lee Duncan Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman