• Nicholas Bellinger's avatar
    target: Fix node_acl demo-mode + uncached dynamic shutdown regression · 6f48655f
    Nicholas Bellinger authored
    This patch fixes a generate_node_acls = 1 + cache_dynamic_acls = 0
    regression, that was introduced by
    
      commit 01d4d673
      Author: Nicholas Bellinger <nab@linux-iscsi.org>
      Date:   Wed Dec 7 12:55:54 2016 -0800
    
    which originally had the proper list_del_init() usage, but was
    dropped during list review as it was thought unnecessary by HCH.
    
    However, list_del_init() usage is required during the special
    generate_node_acls = 1 + cache_dynamic_acls = 0 case when
    transport_free_session() does a list_del(&se_nacl->acl_list),
    followed by target_complete_nacl() doing the same thing.
    
    This was manifesting as a general protection fault as reported
    by Justin:
    
    kernel: general protection fault: 0000 [#1] SMP
    kernel: Modules linked in:
    kernel: CPU: 0 PID: 11047 Comm: iscsi_ttx Not tainted 4.13.0-rc2.x86_64.1+ #20
    kernel: Hardware name: Intel Corporation S5500BC/S5500BC, BIOS S5500.86B.01.00.0064.050520141428 05/05/2014
    kernel: task: ffff88026939e800 task.stack: ffffc90007884000
    kernel: RIP: 0010:target_put_nacl+0x49/0xb0
    kernel: RSP: 0018:ffffc90007887d70 EFLAGS: 00010246
    kernel: RAX: dead000000000200 RBX: ffff8802556ca000 RCX: 0000000000000000
    kernel: RDX: dead000000000100 RSI: 0000000000000246 RDI: ffff8802556ce028
    kernel: RBP: ffffc90007887d88 R08: 0000000000000001 R09: 0000000000000000
    kernel: R10: ffffc90007887df8 R11: ffffea0009986900 R12: ffff8802556ce020
    kernel: R13: ffff8802556ce028 R14: ffff8802556ce028 R15: ffffffff88d85540
    kernel: FS:  0000000000000000(0000) GS:ffff88027fc00000(0000) knlGS:0000000000000000
    kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    kernel: CR2: 00007fffe36f5f94 CR3: 0000000009209000 CR4: 00000000003406f0
    kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
    kernel: Call Trace:
    kernel:  transport_free_session+0x67/0x140
    kernel:  transport_deregister_session+0x7a/0xc0
    kernel:  iscsit_close_session+0x92/0x210
    kernel:  iscsit_close_connection+0x5f9/0x840
    kernel:  iscsit_take_action_for_connection_exit+0xfe/0x110
    kernel:  iscsi_target_tx_thread+0x140/0x1e0
    kernel:  ? wait_woken+0x90/0x90
    kernel:  kthread+0x124/0x160
    kernel:  ? iscsit_thread_get_cpumask+0x90/0x90
    kernel:  ? kthread_create_on_node+0x40/0x40
    kernel:  ret_from_fork+0x22/0x30
    kernel: Code: 00 48 89 fb 4c 8b a7 48 01 00 00 74 68 4d 8d 6c 24 08 4c
    89 ef e8 e8 28 43 00 48 8b 93 20 04 00 00 48 8b 83 28 04 00 00 4c 89
    ef <48> 89 42 08 48 89 10 48 b8 00 01 00 00 00 00 ad de 48 89 83 20
    kernel: RIP: target_put_nacl+0x49/0xb0 RSP: ffffc90007887d70
    kernel: ---[ end trace f12821adbfd46fed ]---
    
    To address this, go ahead and use proper list_del_list() for all
    cases of se_nacl->acl_list deletion.
    Reported-by: default avatarJustin Maggard <jmaggard01@gmail.com>
    Tested-by: default avatarJustin Maggard <jmaggard01@gmail.com>
    Cc: Justin Maggard <jmaggard01@gmail.com>
    Cc: stable@vger.kernel.org # 4.1+
    Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
    6f48655f