Hi, on my system I can't logout from iSCSI session when on 4.4.18, but 4.3.19 works just fine. git bisect points to fbce4d97fd ("scsi: fixup kernel warning during rmmod()") Bug manifests itself like following: - iSCSI session logout hangs and never completes - 1 kworker per iSCSI session start consuming 100% CPU - very shortly one of 2 errors show up in dmesg (full listings are below): * kernel: list_del corruption, ffff88c1cd6bb810->next is LIST_POISON1 * kernel BUG at mm/slub.c:295! Ways to trigger bug: 1. initiate iSCSI sessions to multiple portals 2. let multipathd to create multipath devices 3. run 'iscsiadm -m node --logoutall=all' Bugs is NOT triggered and iSCSI logout succeeds when either: - multipathd is masked and never started - I manually delete all scsi devices via /sys/block/$d/device/delete before attempting to do iSCSI logout list_del_corrpution: Feb 16 10:37:11 localhost.localdomain kernel: alua: device handler registered Feb 16 10:37:11 localhost.localdomain kernel: emc: device handler registered Feb 16 10:37:11 localhost.localdomain kernel: rdac: device handler registered Feb 16 10:37:11 localhost.localdomain kernel: device-mapper: multipath service-time: version 0.3.0 loaded Feb 16 10:38:38 localhost.localdomain kernel: list_del corruption, ffff88c1cd6bb810->next is LIST_POISON1 (dead000000000100) Feb 16 10:38:38 localhost.localdomain kernel: ------------[ cut here ]------------ Feb 16 10:38:38 localhost.localdomain kernel: kernel BUG at lib/list_debug.c:47! Feb 16 10:38:38 localhost.localdomain kernel: invalid opcode: 0000 [#1] SMP PTI Feb 16 10:38:38 localhost.localdomain kernel: Modules linked in: dm_service_time dm_multipath scsi_dh_rdac scsi_dh_emc scsi_dh_alua binfmt_misc iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ip_set nfnetlink ebtable_nat ebtable_broute bridge stp llc ip6tabl Feb 16 10:38:38 localhost.localdomain kernel: pata_acpi Feb 16 10:38:38 localhost.localdomain kernel: CPU: 2 PID: 5 Comm: kworker/u24:0 Not tainted 4.14.18-300.fc27.x86_64 #1 Feb 16 10:38:38 localhost.localdomain kernel: Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 09/21/2015 Feb 16 10:38:38 localhost.localdomain kernel: Workqueue: scsi_wq_5 __iscsi_unbind_session [scsi_transport_iscsi] Feb 16 10:38:38 localhost.localdomain kernel: task: ffff88bdede83e80 task.stack: ffffb15043158000 Feb 16 10:38:38 localhost.localdomain kernel: RIP: 0010:__list_del_entry_valid+0x4e/0x90 Feb 16 10:38:38 localhost.localdomain kernel: RSP: 0018:ffffb1504315bd88 EFLAGS: 00010082 Feb 16 10:38:38 localhost.localdomain kernel: RAX: 000000000000004e RBX: ffff88c1cd6bbf38 RCX: 0000000000000000 Feb 16 10:38:38 localhost.localdomain kernel: RDX: 0000000000000000 RSI: ffff88bdefc96a38 RDI: ffff88bdefc96a38 Feb 16 10:38:38 localhost.localdomain kernel: RBP: 0000000000000246 R08: 00000000000007be R09: 0000000000aaaaaa Feb 16 10:38:38 localhost.localdomain kernel: R10: ffffb1504315bd58 R11: 00000000ffffffff R12: ffff88c1ebb659c0 Feb 16 10:38:38 localhost.localdomain kernel: R13: ffff88bdec827010 R14: ffff88c1cd6bb800 R15: ffff88c1cd6bb800 Feb 16 10:38:38 localhost.localdomain kernel: FS: 0000000000000000(0000) GS:ffff88bdefc80000(0000) knlGS:0000000000000000 Feb 16 10:38:38 localhost.localdomain kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Feb 16 10:38:38 localhost.localdomain kernel: CR2: 0000563d0c1ed280 CR3: 000000057120a001 CR4: 00000000001606e0 Feb 16 10:38:38 localhost.localdomain kernel: Call Trace: Feb 16 10:38:38 localhost.localdomain kernel: scsi_device_dev_release_usercontext+0x52/0x250 Feb 16 10:38:38 localhost.localdomain kernel: ? __schedule+0x10f/0x880 Feb 16 10:38:38 localhost.localdomain kernel: execute_in_process_context+0x21/0x60 Feb 16 10:38:38 localhost.localdomain kernel: device_release+0x30/0x80 Feb 16 10:38:38 localhost.localdomain kernel: kobject_put+0x80/0x1a0 Feb 16 10:38:38 localhost.localdomain kernel: scsi_remove_target+0x16d/0x1b0 Feb 16 10:38:38 localhost.localdomain kernel: __iscsi_unbind_session+0xad/0x150 [scsi_transport_iscsi] Feb 16 10:38:38 localhost.localdomain kernel: process_one_work+0x184/0x3a0 Feb 16 10:38:38 localhost.localdomain kernel: worker_thread+0x2e/0x380 Feb 16 10:38:38 localhost.localdomain kernel: ? process_one_work+0x3a0/0x3a0 Feb 16 10:38:38 localhost.localdomain kernel: kthread+0x11a/0x130 Feb 16 10:38:38 localhost.localdomain kernel: ? kthread_park+0x60/0x60 Feb 16 10:38:38 localhost.localdomain kernel: ret_from_fork+0x35/0x40 Feb 16 10:38:38 localhost.localdomain kernel: Code: 74 2b 48 8b 32 48 39 fe 75 34 48 8b 50 08 48 39 f2 75 3f b8 01 00 00 00 c3 48 89 fe 48 89 c2 48 c7 c7 90 c6 0c bf e8 0d 94 cc ff <0f> 0b 48 89 fe 48 c7 c7 c8 c6 0c bf e8 fc 93 cc ff 0f 0b 48 89 Feb 16 10:38:38 localhost.localdomain kernel: RIP: __list_del_entry_valid+0x4e/0x90 RSP: ffffb1504315bd88 Feb 16 10:38:38 localhost.localdomain kernel: ---[ end trace 20bb15aa6c0307f2 ]--- Feb 16 10:38:38 localhost.localdomain kernel: device-mapper: multipath: Failing path 65:0. Feb 16 10:38:39 localhost.localdomain kernel: print_req_error: I/O error, dev dm-2, sector 2097024 Feb 16 10:38:39 localhost.localdomain kernel: print_req_error: I/O error, dev dm-2, sector 2097024 Feb 16 10:38:39 localhost.localdomain kernel: Buffer I/O error on dev dm-2, logical block 262128, async page read Feb 16 10:38:39 localhost.localdomain kernel: device-mapper: multipath: Failing path 65:64. Feb 16 10:38:40 localhost.localdomain kernel: device-mapper: multipath: Failing path 65:112. Feb 16 10:38:41 localhost.localdomain kernel: device-mapper: multipath: Failing path 65:208. Feb 16 10:38:42 localhost.localdomain kernel: device-mapper: multipath: Failing path 8:112. Feb 16 10:38:43 localhost.localdomain kernel: device-mapper: multipath: Failing path 8:208. Feb 16 10:38:43 localhost.localdomain kernel: device-mapper: multipath: Failing path 8:208. Feb 16 10:38:43 localhost.localdomain kernel: list_del corruption, ffff88c1ebc26010->next is LIST_POISON1 (dead000000000100) kernel BUG at mm/slub.c: [ 70.433229] scsi 3:0:0:0: alua: Detached [ 70.433233] ------------[ cut here ]------------ [ 70.433234] kernel BUG at mm/slub.c:295! [ 70.433253] invalid opcode: 0000 [#1] SMP PTI [ 70.433265] Modules linked in: ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ip_set nfnetlink ebtable_nat ebtable_broute bridge stp llc ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_raw ip6table_security iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_raw iptable_security dm_service_time ebtable_filter ebtables ip6table_filter ip6_tables vmw_vsock_vmci_transport vsock sunrpc sb_edac crct10dif_pclmul crc32_pclmul vmw_balloon ghash_clmulni_intel intel_rapl_perf joydev i2c_piix4 vmw_vmci shpchp dm_multipath scsi_dh_rdac scsi_dh_emc scsi_dh_alua iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi xfs libcrc32c vmwgfx drm_kms_helper ttm drm crc32c_intel ata_generic serio_raw vmxnet3 vmw_pvscsi pata_acpi [ 70.433441] CPU: 10 PID: 776 Comm: multipathd Not tainted 4.14.18-300.fc27.x86_64 #1 [ 70.433458] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 09/21/2015 [ 70.433483] task: ffff99ab2b5ebe80 task.stack: ffffb07f83a64000 [ 70.433500] RIP: 0010:__slab_free+0x18b/0x300 [ 70.433511] RSP: 0018:ffffb07f83a67cb0 EFLAGS: 00010246 [ 70.433525] RAX: ffff99ab2b11ff00 RBX: ffff99ab2b11ff00 RCX: 00000001802a0022 [ 70.433542] RDX: ffff99ab2b11ff00 RSI: fffff31490ac47c0 RDI: ffff99ab2f803680 [ 70.433558] RBP: ffffb07f83a67d50 R08: 0000000000000001 R09: ffffffff815cccbe [ 70.433574] R10: fffff31490ac47c0 R11: 0000000000000000 R12: ffff99ab2f803680 [ 70.433591] R13: fffff31490ac47c0 R14: ffff99ab2b11ff00 R15: ffff99ab2d742fb0 [ 70.433607] FS: 00007f6d65a7a700(0000) GS:ffff99af3fd00000(0000) knlGS:0000000000000000 [ 70.433626] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 70.433640] CR2: 00007f4a983c67f8 CR3: 000000082a726001 CR4: 00000000001606e0 [ 70.433688] Call Trace: [ 70.433701] ? __wake_up_common_lock+0x89/0xc0 [ 70.433715] ? __slab_free+0x15b/0x300 [ 70.433726] ? scsi_dh_release_device+0x1e/0x60 [ 70.433738] scsi_dh_release_device+0x1e/0x60 [ 70.433750] scsi_device_dev_release_usercontext+0x2a/0x250 [ 70.434206] execute_in_process_context+0x21/0x60 [ 70.434643] device_release+0x30/0x80 [ 70.435098] kobject_put+0x80/0x1a0 [ 70.435525] scsi_disk_put+0x2b/0x40 [ 70.435942] __blkdev_put+0x197/0x1f0 [ 70.436355] blkdev_close+0x21/0x30 [ 70.436756] __fput+0xd0/0x1e0 [ 70.437152] task_work_run+0x84/0xa0 [ 70.437539] exit_to_usermode_loop+0x9e/0xa0 [ 70.437917] do_syscall_64+0x173/0x180 [ 70.438133] device-mapper: multipath: Failing path 65:16. [ 70.438140] device-mapper: multipath: Failing path 65:0. [ 70.438985] entry_SYSCALL_64_after_hwframe+0x21/0x86 [ 70.439325] RIP: 0033:0x7f6d64a3a70c [ 70.439648] RSP: 002b:00007f6d65a78880 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 [ 70.439974] RAX: 0000000000000000 RBX: 00007f6d4c0306f0 RCX: 00007f6d64a3a70c [ 70.440293] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 000000000000000a [ 70.440605] RBP: 00007f6d4c030a68 R08: 0000000000000054 R09: 0000000000000080 [ 70.440907] R10: 00000000ffffffdf R11: 0000000000000293 R12: 000055867dd47410 [ 70.441199] R13: 0000000000000000 R14: 0000000000000001 R15: 00007f6d4c03be00 [ 70.441486] Code: fe ff ff 44 0f b6 bd 7f ff ff ff 80 7d ab 00 79 05 45 84 ff 74 7b 48 83 c4 78 5b 41 5c 41 5d 41 5e 41 5f 5d 49 8d 65 f0 41 5d c3 <0f> 0b 4c 89 d0 4c 89 55 88 45 89 fa 48 85 c0 44 0f b6 bd 7f ff [ 70.442406] RIP: __slab_free+0x18b/0x300 RSP: ffffb07f83a67cb0 [ 70.442735] ---[ end trace c79c468d1b715f7e ]--- [ 70.540044] device-mapper: multipath: Failing path 8:32.