From f4bd4294a55b2a0e897148bf25a32e189abda38a Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bart.vanassche@sandisk.com>
Date: Mon, 9 Nov 2015 21:19:42 +0000
Subject: [PATCH] scst_vdisk: Make expl_alua sysfs attribute input validation
 more strict

git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@6640 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 scst/include/backport.h            | 26 ++++++++++++++++++++++++++
 scst/src/dev_handlers/scst_vdisk.c |  9 ++++++---
 2 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/scst/include/backport.h b/scst/include/backport.h
index 53a2f55ab..f349bb80a 100644
--- a/scst/include/backport.h
+++ b/scst/include/backport.h
@@ -255,6 +255,32 @@ static inline void hex2bin(u8 *dst, const char *src, size_t count)
 }
 #endif
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 39)
+static inline int __must_check kstrtoull(const char *s, unsigned int base,
+					 unsigned long long *res)
+{
+	return strict_strtoull(s, base, res);
+}
+
+static inline int __must_check kstrtoll(const char *s, unsigned int base,
+					long long *res)
+{
+	return strict_strtoll(s, base, res);
+}
+
+static inline int __must_check kstrtoul(const char *s, unsigned int base,
+					unsigned long *res)
+{
+	return strict_strtoul(s, base, res);
+}
+
+static inline int __must_check kstrtol(const char *s, unsigned int base,
+				       long *res)
+{
+	return strict_strtol(s, base, res);
+}
+#endif
+
 /* <linux/list.h> */
 
 #ifndef __list_for_each
diff --git a/scst/src/dev_handlers/scst_vdisk.c b/scst/src/dev_handlers/scst_vdisk.c
index f3788afa0..952b73d33 100644
--- a/scst/src/dev_handlers/scst_vdisk.c
+++ b/scst/src/dev_handlers/scst_vdisk.c
@@ -8823,7 +8823,7 @@ static ssize_t vdisk_sysfs_expl_alua_store(struct kobject *kobj,
 	struct scst_device *dev;
 	struct scst_vdisk_dev *virt_dev;
 	char ch[16];
-	bool expl_alua;
+	unsigned long expl_alua;
 	int res;
 
 	TRACE_ENTRY();
@@ -8831,14 +8831,17 @@ static ssize_t vdisk_sysfs_expl_alua_store(struct kobject *kobj,
 	dev = container_of(kobj, struct scst_device, dev_kobj);
 	virt_dev = dev->dh_priv;
 	sprintf(ch, "%.*s", min_t(int, sizeof(ch) - 1, count), buf);
-	expl_alua = !!simple_strtoul(ch, NULL, 0);
+	res = kstrtoul(ch, NULL, &expl_alua);
+	if (res < 0)
+		goto out;
 
 	spin_lock(&virt_dev->flags_lock);
-	virt_dev->expl_alua = expl_alua;
+	virt_dev->expl_alua = !!expl_alua;
 	spin_unlock(&virt_dev->flags_lock);
 
 	res = count;
 
+out:
 	TRACE_EXIT_RES(res);
 	return res;
 }