From f1453773514bb8b0bba0716301e8c8f17f8d39c7 Mon Sep 17 00:00:00 2001
From: Nicholas Bellinger <nab@linux-iscsi.org>
Date: Fri, 6 Jun 2014 00:52:57 -0700
Subject: [PATCH] target: Fix alua_access_state attribute OOPs for
 un-configured devices

This patch fixes a OOPs where an attempt to write to the per-device
alua_access_state configfs attribute at:

  /sys/kernel/config/target/core/$HBA/$DEV/alua/$TG_PT_GP/alua_access_state

results in an NULL pointer dereference when the backend device has not
yet been configured.

This patch adds an explicit check for DF_CONFIGURED, and fails with
-ENODEV to avoid this case.

Reported-by: Chris Boot <crb@tiger-computing.co.uk>
Reported-by: Philip Gaw <pgaw@darktech.org.uk>
Cc: Chris Boot <crb@tiger-computing.co.uk>
Cc: Philip Gaw <pgaw@darktech.org.uk>
Cc: stable@vger.kernel.org # 3.8+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 drivers/target/target_core_configfs.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
index 60a9ae6df763d..bf55c5a04cfac 100644
--- a/drivers/target/target_core_configfs.c
+++ b/drivers/target/target_core_configfs.c
@@ -2227,6 +2227,11 @@ static ssize_t target_core_alua_tg_pt_gp_store_attr_alua_access_state(
 			" tg_pt_gp ID: %hu\n", tg_pt_gp->tg_pt_gp_valid_id);
 		return -EINVAL;
 	}
+	if (!(dev->dev_flags & DF_CONFIGURED)) {
+		pr_err("Unable to set alua_access_state while device is"
+		       " not configured\n");
+		return -ENODEV;
+	}
 
 	ret = kstrtoul(page, 0, &tmp);
 	if (ret < 0) {
-- 
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