4.4-stable review patch. If anyone has any objections, please let me know.
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From: Nicholas Bellinger nab@linux-iscsi.org
commit 6f48655facfd7f7ccfe6d252ac0fe319ab02e4dd upstream.
This patch fixes a generate_node_acls = 1 + cache_dynamic_acls = 0 regression, that was introduced by
commit 01d4d673558985d9a118e1e05026633c3e2ade9b 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: Justin Maggard jmaggard01@gmail.com Tested-by: Justin Maggard jmaggard01@gmail.com Cc: Justin Maggard jmaggard01@gmail.com Signed-off-by: Nicholas Bellinger nab@linux-iscsi.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/target/target_core_tpg.c | 4 ++-- drivers/target/target_core_transport.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-)
--- a/drivers/target/target_core_tpg.c +++ b/drivers/target/target_core_tpg.c @@ -350,7 +350,7 @@ void core_tpg_del_initiator_node_acl(str if (acl->dynamic_node_acl) { acl->dynamic_node_acl = 0; } - list_del(&acl->acl_list); + list_del_init(&acl->acl_list); tpg->num_node_acls--; mutex_unlock(&tpg->acl_node_mutex);
@@ -572,7 +572,7 @@ int core_tpg_deregister(struct se_portal * in transport_deregister_session(). */ list_for_each_entry_safe(nacl, nacl_tmp, &node_list, acl_list) { - list_del(&nacl->acl_list); + list_del_init(&nacl->acl_list); se_tpg->num_node_acls--;
core_tpg_wait_for_nacl_pr_ref(nacl); --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -431,7 +431,7 @@ static void target_complete_nacl(struct }
mutex_lock(&se_tpg->acl_node_mutex); - list_del(&nacl->acl_list); + list_del_init(&nacl->acl_list); mutex_unlock(&se_tpg->acl_node_mutex);
core_tpg_wait_for_nacl_pr_ref(nacl); @@ -503,7 +503,7 @@ void transport_free_session(struct se_se spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
if (se_nacl->dynamic_stop) - list_del(&se_nacl->acl_list); + list_del_init(&se_nacl->acl_list); } mutex_unlock(&se_tpg->acl_node_mutex);