[PATCH AUTOSEL 4.20 058/117] scsi: target: use consistent left-aligned ASCII INQUIRY data

[PATCH AUTOSEL 4.20 058/117] scsi: target: use consistent left-aligned ASCII INQUIRY data

[Sasha Levin]

From: David Disseldorp <ddiss@suse.de>

[ Upstream commit 0de263577de5d5e052be5f4f93334e63cc8a7f0b ]

spc5r17.pdf specifies:

  4.3.1 ASCII data field requirements
  ASCII data fields shall contain only ASCII printable characters (i.e.,
  code values 20h to 7Eh) and may be terminated with one or more ASCII null
  (00h) characters.  ASCII data fields described as being left-aligned
  shall have any unused bytes at the end of the field (i.e., highest
  offset) and the unused bytes shall be filled with ASCII space characters
  (20h).

LIO currently space-pads the T10 VENDOR IDENTIFICATION and PRODUCT
IDENTIFICATION fields in the standard INQUIRY data. However, the PRODUCT
REVISION LEVEL field in the standard INQUIRY data as well as the T10 VENDOR
IDENTIFICATION field in the INQUIRY Device Identification VPD Page are
zero-terminated/zero-padded.

Fix this inconsistency by using space-padding for all of the above fields.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bryant G. Ly <bly@catalogicsoftware.com>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/target/target_core_spc.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
index f459118bc11b..c37dd36ec77d 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -108,12 +108,17 @@ spc_emulate_inquiry_std(struct se_cmd *cmd, unsigned char *buf)
 
 	buf[7] = 0x2; /* CmdQue=1 */
 
-	memcpy(&buf[8], "LIO-ORG ", 8);
-	memset(&buf[16], 0x20, 16);
+	/*
+	 * ASCII data fields described as being left-aligned shall have any
+	 * unused bytes at the end of the field (i.e., highest offset) and the
+	 * unused bytes shall be filled with ASCII space characters (20h).
+	 */
+	memset(&buf[8], 0x20, 8 + 16 + 4);
+	memcpy(&buf[8], "LIO-ORG", sizeof("LIO-ORG") - 1);
 	memcpy(&buf[16], dev->t10_wwn.model,
-	       min_t(size_t, strlen(dev->t10_wwn.model), 16));
+	       strnlen(dev->t10_wwn.model, 16));
 	memcpy(&buf[32], dev->t10_wwn.revision,
-	       min_t(size_t, strlen(dev->t10_wwn.revision), 4));
+	       strnlen(dev->t10_wwn.revision, 4));
 	buf[4] = 31; /* Set additional length to 31 */
 
 	return 0;
@@ -251,7 +256,9 @@ spc_emulate_evpd_83(struct se_cmd *cmd, unsigned char *buf)
 	buf[off] = 0x2; /* ASCII */
 	buf[off+1] = 0x1; /* T10 Vendor ID */
 	buf[off+2] = 0x0;
-	memcpy(&buf[off+4], "LIO-ORG", 8);
+	/* left align Vendor ID and pad with spaces */
+	memset(&buf[off+4], 0x20, 8);
+	memcpy(&buf[off+4], "LIO-ORG", sizeof("LIO-ORG") - 1);
 	/* Extra Byte for NULL Terminator */
 	id_len++;
 	/* Identifier Length */
-- 
2.19.1

[PATCH AUTOSEL 4.20 059/117] scsi: target/core: Make sure that target_wait_for_sess_cmds() waits lon

[Sasha Levin]

From: Bart Van Assche <bvanassche@acm.org>

[ Upstream commit ad669505c4e9db9af9faeb5c51aa399326a80d91 ]

A session must only be released after all code that accesses the session
structure has finished. Make sure that this is the case by introducing a
new command counter per session that is only decremented after the
.release_cmd() callback has finished. This patch fixes the following crash:

BUG: KASAN: use-after-free in do_raw_spin_lock+0x1c/0x130
Read of size 4 at addr ffff8801534b16e4 by task rmdir/14805
CPU: 16 PID: 14805 Comm: rmdir Not tainted 4.18.0-rc2-dbg+ #5
Call Trace:
dump_stack+0xa4/0xf5
print_address_description+0x6f/0x270
kasan_report+0x241/0x360
__asan_load4+0x78/0x80
do_raw_spin_lock+0x1c/0x130
_raw_spin_lock_irqsave+0x52/0x60
srpt_set_ch_state+0x27/0x70 [ib_srpt]
srpt_disconnect_ch+0x1b/0xc0 [ib_srpt]
srpt_close_session+0xa8/0x260 [ib_srpt]
target_shutdown_sessions+0x170/0x180 [target_core_mod]
core_tpg_del_initiator_node_acl+0xf3/0x200 [target_core_mod]
target_fabric_nacl_base_release+0x25/0x30 [target_core_mod]
config_item_release+0x9c/0x110 [configfs]
config_item_put+0x26/0x30 [configfs]
configfs_rmdir+0x3b8/0x510 [configfs]
vfs_rmdir+0xb3/0x1e0
do_rmdir+0x262/0x2c0
do_syscall_64+0x77/0x230
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Mike Christie <mchristi@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Disseldorp <ddiss@suse.de>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/target/target_core_transport.c | 35 ++++++++++++++++++--------
 drivers/target/target_core_xcopy.c     |  6 ++++-
 include/target/target_core_base.h      |  1 +
 include/target/target_core_fabric.h    |  2 +-
 4 files changed, 32 insertions(+), 12 deletions(-)

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 2cfd61d62e97..ffa5b9f771b5 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -224,19 +224,28 @@ void transport_subsystem_check_init(void)
 	sub_api_initialized = 1;
 }
 
+static void target_release_sess_cmd_refcnt(struct percpu_ref *ref)
+{
+	struct se_session *sess = container_of(ref, typeof(*sess), cmd_count);
+
+	wake_up(&sess->cmd_list_wq);
+}
+
 /**
  * transport_init_session - initialize a session object
  * @se_sess: Session object pointer.
  *
  * The caller must have zero-initialized @se_sess before calling this function.
  */
-void transport_init_session(struct se_session *se_sess)
+int transport_init_session(struct se_session *se_sess)
 {
 	INIT_LIST_HEAD(&se_sess->sess_list);
 	INIT_LIST_HEAD(&se_sess->sess_acl_list);
 	INIT_LIST_HEAD(&se_sess->sess_cmd_list);
 	spin_lock_init(&se_sess->sess_cmd_lock);
 	init_waitqueue_head(&se_sess->cmd_list_wq);
+	return percpu_ref_init(&se_sess->cmd_count,
+			       target_release_sess_cmd_refcnt, 0, GFP_KERNEL);
 }
 EXPORT_SYMBOL(transport_init_session);
 
@@ -247,6 +256,7 @@ EXPORT_SYMBOL(transport_init_session);
 struct se_session *transport_alloc_session(enum target_prot_op sup_prot_ops)
 {
 	struct se_session *se_sess;
+	int ret;
 
 	se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
 	if (!se_sess) {
@@ -254,7 +264,11 @@ struct se_session *transport_alloc_session(enum target_prot_op sup_prot_ops)
 				" se_sess_cache\n");
 		return ERR_PTR(-ENOMEM);
 	}
-	transport_init_session(se_sess);
+	ret = transport_init_session(se_sess);
+	if (ret < 0) {
+		kfree(se_sess);
+		return ERR_PTR(ret);
+	}
 	se_sess->sup_prot_ops = sup_prot_ops;
 
 	return se_sess;
@@ -581,6 +595,7 @@ void transport_free_session(struct se_session *se_sess)
 		sbitmap_queue_free(&se_sess->sess_tag_pool);
 		kvfree(se_sess->sess_cmd_map);
 	}
+	percpu_ref_exit(&se_sess->cmd_count);
 	kmem_cache_free(se_sess_cache, se_sess);
 }
 EXPORT_SYMBOL(transport_free_session);
@@ -2719,6 +2734,7 @@ int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
 	}
 	se_cmd->transport_state |= CMD_T_PRE_EXECUTE;
 	list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
+	percpu_ref_get(&se_sess->cmd_count);
 out:
 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
 
@@ -2749,8 +2765,6 @@ static void target_release_cmd_kref(struct kref *kref)
 	if (se_sess) {
 		spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
 		list_del_init(&se_cmd->se_cmd_list);
-		if (se_sess->sess_tearing_down && list_empty(&se_sess->sess_cmd_list))
-			wake_up(&se_sess->cmd_list_wq);
 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
 	}
 
@@ -2758,6 +2772,8 @@ static void target_release_cmd_kref(struct kref *kref)
 	se_cmd->se_tfo->release_cmd(se_cmd);
 	if (compl)
 		complete(compl);
+
+	percpu_ref_put(&se_sess->cmd_count);
 }
 
 /**
@@ -2886,6 +2902,8 @@ void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
 	se_sess->sess_tearing_down = 1;
 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
+
+	percpu_ref_kill(&se_sess->cmd_count);
 }
 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
 
@@ -2900,17 +2918,14 @@ void target_wait_for_sess_cmds(struct se_session *se_sess)
 
 	WARN_ON_ONCE(!se_sess->sess_tearing_down);
 
-	spin_lock_irq(&se_sess->sess_cmd_lock);
 	do {
-		ret = wait_event_lock_irq_timeout(
-				se_sess->cmd_list_wq,
-				list_empty(&se_sess->sess_cmd_list),
-				se_sess->sess_cmd_lock, 180 * HZ);
+		ret = wait_event_timeout(se_sess->cmd_list_wq,
+				percpu_ref_is_zero(&se_sess->cmd_count),
+				180 * HZ);
 		list_for_each_entry(cmd, &se_sess->sess_cmd_list, se_cmd_list)
 			target_show_cmd("session shutdown: still waiting for ",
 					cmd);
 	} while (ret <= 0);
-	spin_unlock_irq(&se_sess->sess_cmd_lock);
 }
 EXPORT_SYMBOL(target_wait_for_sess_cmds);
 
diff --git a/drivers/target/target_core_xcopy.c b/drivers/target/target_core_xcopy.c
index 70adcfdca8d1..124495f953fa 100644
--- a/drivers/target/target_core_xcopy.c
+++ b/drivers/target/target_core_xcopy.c
@@ -479,6 +479,8 @@ static const struct target_core_fabric_ops xcopy_pt_tfo = {
 
 int target_xcopy_setup_pt(void)
 {
+	int ret;
+
 	xcopy_wq = alloc_workqueue("xcopy_wq", WQ_MEM_RECLAIM, 0);
 	if (!xcopy_wq) {
 		pr_err("Unable to allocate xcopy_wq\n");
@@ -496,7 +498,9 @@ int target_xcopy_setup_pt(void)
 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_list);
 	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_sess_list);
 	memset(&xcopy_pt_sess, 0, sizeof(struct se_session));
-	transport_init_session(&xcopy_pt_sess);
+	ret = transport_init_session(&xcopy_pt_sess);
+	if (ret < 0)
+		return ret;
 
 	xcopy_pt_nacl.se_tpg = &xcopy_pt_tpg;
 	xcopy_pt_nacl.nacl_sess = &xcopy_pt_sess;
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index e3bdb0550a59..d9fd4eac58c2 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -601,6 +601,7 @@ struct se_session {
 	struct se_node_acl	*se_node_acl;
 	struct se_portal_group *se_tpg;
 	void			*fabric_sess_ptr;
+	struct percpu_ref	cmd_count;
 	struct list_head	sess_list;
 	struct list_head	sess_acl_list;
 	struct list_head	sess_cmd_list;
diff --git a/include/target/target_core_fabric.h b/include/target/target_core_fabric.h
index f4147b398431..eb9d0923c55c 100644
--- a/include/target/target_core_fabric.h
+++ b/include/target/target_core_fabric.h
@@ -116,7 +116,7 @@ struct se_session *target_setup_session(struct se_portal_group *,
 				struct se_session *, void *));
 void target_remove_session(struct se_session *);
 
-void transport_init_session(struct se_session *);
+int transport_init_session(struct se_session *se_sess);
 struct se_session *transport_alloc_session(enum target_prot_op);
 int transport_alloc_session_tags(struct se_session *, unsigned int,
 		unsigned int);
-- 
2.19.1