Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI fixes from James Bottomley:
 "Six fixes, all in drivers.

  The biggest are the UFS devfreq fixes which address a lock inversion
  and the two iscsi_tcp fixes which try to prevent a use after free from
  userspace still accessing an area which the kernel has released (seen
  by KASAN)"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: device_handler: alua: Remove a might_sleep() annotation
  scsi: iscsi_tcp: Fix UAF during login when accessing the shost ipaddress
  scsi: iscsi_tcp: Fix UAF during logout when accessing the shost ipaddress
  scsi: ufs: core: Fix devfreq deadlocks
  scsi: hpsa: Fix allocation size for scsi_host_alloc()
  scsi: target: core: Fix warning on RT kernels

6 files changed, 67 insertions, 31 deletions

diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index 49cc18a87473..29a2865b8e2e 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -981,6 +981,9 @@ queue_rtpg:
  *
  * Returns true if and only if alua_rtpg_work() will be called asynchronously.
  * That function is responsible for calling @qdata->fn().
+ *
+ * Context: may be called from atomic context (alua_check()) only if the caller
+ *	holds an sdev reference.
  */
 static bool alua_rtpg_queue(struct alua_port_group *pg,
 			    struct scsi_device *sdev,
@@ -989,8 +992,6 @@ static bool alua_rtpg_queue(struct alua_port_group *pg,
 	int start_queue = 0;
 	unsigned long flags;
 
-	might_sleep();
-
 	if (WARN_ON_ONCE(!pg) || scsi_device_get(sdev))
 		return false;
 
diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 4dbf51e2623a..f6da34850af9 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -5850,7 +5850,7 @@ static int hpsa_scsi_host_alloc(struct ctlr_info *h)
 {
 	struct Scsi_Host *sh;
 
-	sh = scsi_host_alloc(&hpsa_driver_template, sizeof(h));
+	sh = scsi_host_alloc(&hpsa_driver_template, sizeof(struct ctlr_info));
 	if (sh == NULL) {
 		dev_err(&h->pdev->dev, "scsi_host_alloc failed\n");
 		return -ENOMEM;
diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 1d1cf641937c..0454d94e8cf0 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -849,7 +849,7 @@ static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost,
 				       enum iscsi_host_param param, char *buf)
 {
 	struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost);
-	struct iscsi_session *session = tcp_sw_host->session;
+	struct iscsi_session *session;
 	struct iscsi_conn *conn;
 	struct iscsi_tcp_conn *tcp_conn;
 	struct iscsi_sw_tcp_conn *tcp_sw_conn;
@@ -859,6 +859,7 @@ static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost,
 
 	switch (param) {
 	case ISCSI_HOST_PARAM_IPADDRESS:
+		session = tcp_sw_host->session;
 		if (!session)
 			return -ENOTCONN;
 
@@ -959,11 +960,13 @@ iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
 	if (!cls_session)
 		goto remove_host;
 	session = cls_session->dd_data;
-	tcp_sw_host = iscsi_host_priv(shost);
-	tcp_sw_host->session = session;
 
 	if (iscsi_tcp_r2tpool_alloc(session))
 		goto remove_session;
+
+	/* We are now fully setup so expose the session to sysfs. */
+	tcp_sw_host = iscsi_host_priv(shost);
+	tcp_sw_host->session = session;
 	return cls_session;
 
 remove_session:
@@ -983,10 +986,17 @@ static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session)
 	if (WARN_ON_ONCE(session->leadconn))
 		return;
 
+	iscsi_session_remove(cls_session);
+	/*
+	 * Our get_host_param needs to access the session, so remove the
+	 * host from sysfs before freeing the session to make sure userspace
+	 * is no longer accessing the callout.
+	 */
+	iscsi_host_remove(shost, false);
+
 	iscsi_tcp_r2tpool_free(cls_session->dd_data);
-	iscsi_session_teardown(cls_session);
 
-	iscsi_host_remove(shost, false);
+	iscsi_session_free(cls_session);
 	iscsi_host_free(shost);
 }
 
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index ef2fc860257e..127f3d7f19dc 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -3104,17 +3104,32 @@ dec_session_count:
 }
 EXPORT_SYMBOL_GPL(iscsi_session_setup);
 
-/**
- * iscsi_session_teardown - destroy session, host, and cls_session
- * @cls_session: iscsi session
+/*
+ * issi_session_remove - Remove session from iSCSI class.
  */
-void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
+void iscsi_session_remove(struct iscsi_cls_session *cls_session)
 {
 	struct iscsi_session *session = cls_session->dd_data;
-	struct module *owner = cls_session->transport->owner;
 	struct Scsi_Host *shost = session->host;
 
 	iscsi_remove_session(cls_session);
+	/*
+	 * host removal only has to wait for its children to be removed from
+	 * sysfs, and iscsi_tcp needs to do iscsi_host_remove before freeing
+	 * the session, so drop the session count here.
+	 */
+	iscsi_host_dec_session_cnt(shost);
+}
+EXPORT_SYMBOL_GPL(iscsi_session_remove);
+
+/**
+ * iscsi_session_free - Free iscsi session and it's resources
+ * @cls_session: iscsi session
+ */
+void iscsi_session_free(struct iscsi_cls_session *cls_session)
+{
+	struct iscsi_session *session = cls_session->dd_data;
+	struct module *owner = cls_session->transport->owner;
 
 	iscsi_pool_free(&session->cmdpool);
 	kfree(session->password);
@@ -3132,10 +3147,19 @@ void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
 	kfree(session->discovery_parent_type);
 
 	iscsi_free_session(cls_session);
-
-	iscsi_host_dec_session_cnt(shost);
 	module_put(owner);
 }
+EXPORT_SYMBOL_GPL(iscsi_session_free);
+
+/**
+ * iscsi_session_teardown - destroy session and cls_session
+ * @cls_session: iscsi session
+ */
+void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
+{
+	iscsi_session_remove(cls_session);
+	iscsi_session_free(cls_session);
+}
 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
 
 /**
diff --git a/drivers/target/target_core_tmr.c b/drivers/target/target_core_tmr.c
index bac111456fa1..2b95b4550a63 100644
--- a/drivers/target/target_core_tmr.c
+++ b/drivers/target/target_core_tmr.c
@@ -73,8 +73,8 @@ static bool __target_check_io_state(struct se_cmd *se_cmd,
 {
 	struct se_session *sess = se_cmd->se_sess;
 
-	assert_spin_locked(&sess->sess_cmd_lock);
-	WARN_ON_ONCE(!irqs_disabled());
+	lockdep_assert_held(&sess->sess_cmd_lock);
+
 	/*
 	 * If command already reached CMD_T_COMPLETE state within
 	 * target_complete_cmd() or CMD_T_FABRIC_STOP due to shutdown,
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index bda61be5f035..3a1c4d31e010 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -1234,12 +1234,14 @@ static int ufshcd_clock_scaling_prepare(struct ufs_hba *hba)
 	 * clock scaling is in progress
 	 */
 	ufshcd_scsi_block_requests(hba);
+	mutex_lock(&hba->wb_mutex);
 	down_write(&hba->clk_scaling_lock);
 
 	if (!hba->clk_scaling.is_allowed ||
 	    ufshcd_wait_for_doorbell_clr(hba, DOORBELL_CLR_TOUT_US)) {
 		ret = -EBUSY;
 		up_write(&hba->clk_scaling_lock);
+		mutex_unlock(&hba->wb_mutex);
 		ufshcd_scsi_unblock_requests(hba);
 		goto out;
 	}
@@ -1251,12 +1253,16 @@ out:
 	return ret;
 }
 
-static void ufshcd_clock_scaling_unprepare(struct ufs_hba *hba, bool writelock)
+static void ufshcd_clock_scaling_unprepare(struct ufs_hba *hba, int err, bool scale_up)
 {
-	if (writelock)
-		up_write(&hba->clk_scaling_lock);
-	else
-		up_read(&hba->clk_scaling_lock);
+	up_write(&hba->clk_scaling_lock);
+
+	/* Enable Write Booster if we have scaled up else disable it */
+	if (ufshcd_enable_wb_if_scaling_up(hba) && !err)
+		ufshcd_wb_toggle(hba, scale_up);
+
+	mutex_unlock(&hba->wb_mutex);
+
 	ufshcd_scsi_unblock_requests(hba);
 	ufshcd_release(hba);
 }
@@ -1273,7 +1279,6 @@ static void ufshcd_clock_scaling_unprepare(struct ufs_hba *hba, bool writelock)
 static int ufshcd_devfreq_scale(struct ufs_hba *hba, bool scale_up)
 {
 	int ret = 0;
-	bool is_writelock = true;
 
 	ret = ufshcd_clock_scaling_prepare(hba);
 	if (ret)
@@ -1302,15 +1307,8 @@ static int ufshcd_devfreq_scale(struct ufs_hba *hba, bool scale_up)
 		}
 	}
 
-	/* Enable Write Booster if we have scaled up else disable it */
-	if (ufshcd_enable_wb_if_scaling_up(hba)) {
-		downgrade_write(&hba->clk_scaling_lock);
-		is_writelock = false;
-		ufshcd_wb_toggle(hba, scale_up);
-	}
-
 out_unprepare:
-	ufshcd_clock_scaling_unprepare(hba, is_writelock);
+	ufshcd_clock_scaling_unprepare(hba, ret, scale_up);
 	return ret;
 }
 
@@ -6066,9 +6064,11 @@ static void ufshcd_force_error_recovery(struct ufs_hba *hba)
 
 static void ufshcd_clk_scaling_allow(struct ufs_hba *hba, bool allow)
 {
+	mutex_lock(&hba->wb_mutex);
 	down_write(&hba->clk_scaling_lock);
 	hba->clk_scaling.is_allowed = allow;
 	up_write(&hba->clk_scaling_lock);
+	mutex_unlock(&hba->wb_mutex);
 }
 
 static void ufshcd_clk_scaling_suspend(struct ufs_hba *hba, bool suspend)
@@ -9793,6 +9793,7 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
 	/* Initialize mutex for exception event control */
 	mutex_init(&hba->ee_ctrl_mutex);
 
+	mutex_init(&hba->wb_mutex);
 	init_rwsem(&hba->clk_scaling_lock);
 
 	ufshcd_init_clk_gating(hba);