[PATCH] tlclk: if sscanf() fails, fall back to 0, not random value

[Alexander A. Klimov]

If sscanf(IN, FMT, &OUT) fails, OUT may be unchanged.
So if OUT was never initialized, it may be still uninitialized memory.
To prevent such, initialize OUT=0 first.

Fixes: 648bf4fb21f5 ("[PATCH] tlclk driver update")
Fixes: 1a80ba882730 ("[PATCH] Telecom Clock Driver for MPCBL0010 ATCA computer blade")
Signed-off-by: Alexander A. Klimov <grandmaster@xxxxxxxxxxxx>
---
 drivers/char/tlclk.c | 36 ++++++++++++++++++------------------
 1 file changed, 18 insertions(+), 18 deletions(-)

diff --git a/drivers/char/tlclk.c b/drivers/char/tlclk.c
index 677d230a226c..1d0fcf87449d 100644
--- a/drivers/char/tlclk.c
+++ b/drivers/char/tlclk.c
@@ -327,7 +327,7 @@ static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
 static ssize_t store_received_ref_clk3a(struct device *d,
 		 struct device_attribute *attr, const char *buf, size_t count)
 {
-	unsigned long tmp;
+	unsigned long tmp = 0;
 	unsigned char val;
 	unsigned long flags;
 
@@ -349,7 +349,7 @@ static DEVICE_ATTR(received_ref_clk3a, (S_IWUSR|S_IWGRP), NULL,
 static ssize_t store_received_ref_clk3b(struct device *d,
 		 struct device_attribute *attr, const char *buf, size_t count)
 {
-	unsigned long tmp;
+	unsigned long tmp = 0;
 	unsigned char val;
 	unsigned long flags;
 
@@ -371,7 +371,7 @@ static DEVICE_ATTR(received_ref_clk3b, (S_IWUSR|S_IWGRP), NULL,
 static ssize_t store_enable_clk3b_output(struct device *d,
 		 struct device_attribute *attr, const char *buf, size_t count)
 {
-	unsigned long tmp;
+	unsigned long tmp = 0;
 	unsigned char val;
 	unsigned long flags;
 
@@ -393,7 +393,7 @@ static ssize_t store_enable_clk3a_output(struct device *d,
 		 struct device_attribute *attr, const char *buf, size_t count)
 {
 	unsigned long flags;
-	unsigned long tmp;
+	unsigned long tmp = 0;
 	unsigned char val;
 
 	sscanf(buf, "%lX", &tmp);
@@ -414,7 +414,7 @@ static ssize_t store_enable_clkb1_output(struct device *d,
 		 struct device_attribute *attr, const char *buf, size_t count)
 {
 	unsigned long flags;
-	unsigned long tmp;
+	unsigned long tmp = 0;
 	unsigned char val;
 
 	sscanf(buf, "%lX", &tmp);
@@ -436,7 +436,7 @@ static ssize_t store_enable_clka1_output(struct device *d,
 		 struct device_attribute *attr, const char *buf, size_t count)
 {
 	unsigned long flags;
-	unsigned long tmp;
+	unsigned long tmp = 0;
 	unsigned char val;
 
 	sscanf(buf, "%lX", &tmp);
@@ -457,7 +457,7 @@ static ssize_t store_enable_clkb0_output(struct device *d,
 		 struct device_attribute *attr, const char *buf, size_t count)
 {
 	unsigned long flags;
-	unsigned long tmp;
+	unsigned long tmp = 0;
 	unsigned char val;
 
 	sscanf(buf, "%lX", &tmp);
@@ -478,7 +478,7 @@ static ssize_t store_enable_clka0_output(struct device *d,
 		 struct device_attribute *attr, const char *buf, size_t count)
 {
 	unsigned long flags;
-	unsigned long tmp;
+	unsigned long tmp = 0;
 	unsigned char val;
 
 	sscanf(buf, "%lX", &tmp);
@@ -499,7 +499,7 @@ static ssize_t store_select_amcb2_transmit_clock(struct device *d,
 		struct device_attribute *attr, const char *buf, size_t count)
 {
 	unsigned long flags;
-	unsigned long tmp;
+	unsigned long tmp = 0;
 	unsigned char val;
 
 	sscanf(buf, "%lX", &tmp);
@@ -540,7 +540,7 @@ static DEVICE_ATTR(select_amcb2_transmit_clock, (S_IWUSR|S_IWGRP), NULL,
 static ssize_t store_select_amcb1_transmit_clock(struct device *d,
 		 struct device_attribute *attr, const char *buf, size_t count)
 {
-	unsigned long tmp;
+	unsigned long tmp = 0;
 	unsigned char val;
 	unsigned long flags;
 
@@ -582,7 +582,7 @@ static DEVICE_ATTR(select_amcb1_transmit_clock, (S_IWUSR|S_IWGRP), NULL,
 static ssize_t store_select_redundant_clock(struct device *d,
 		 struct device_attribute *attr, const char *buf, size_t count)
 {
-	unsigned long tmp;
+	unsigned long tmp = 0;
 	unsigned char val;
 	unsigned long flags;
 
@@ -603,7 +603,7 @@ static DEVICE_ATTR(select_redundant_clock, (S_IWUSR|S_IWGRP), NULL,
 static ssize_t store_select_ref_frequency(struct device *d,
 		 struct device_attribute *attr, const char *buf, size_t count)
 {
-	unsigned long tmp;
+	unsigned long tmp = 0;
 	unsigned char val;
 	unsigned long flags;
 
@@ -624,7 +624,7 @@ static DEVICE_ATTR(select_ref_frequency, (S_IWUSR|S_IWGRP), NULL,
 static ssize_t store_filter_select(struct device *d,
 		 struct device_attribute *attr, const char *buf, size_t count)
 {
-	unsigned long tmp;
+	unsigned long tmp = 0;
 	unsigned char val;
 	unsigned long flags;
 
@@ -644,7 +644,7 @@ static DEVICE_ATTR(filter_select, (S_IWUSR|S_IWGRP), NULL, store_filter_select);
 static ssize_t store_hardware_switching_mode(struct device *d,
 		 struct device_attribute *attr, const char *buf, size_t count)
 {
-	unsigned long tmp;
+	unsigned long tmp = 0;
 	unsigned char val;
 	unsigned long flags;
 
@@ -665,7 +665,7 @@ static DEVICE_ATTR(hardware_switching_mode, (S_IWUSR|S_IWGRP), NULL,
 static ssize_t store_hardware_switching(struct device *d,
 		 struct device_attribute *attr, const char *buf, size_t count)
 {
-	unsigned long tmp;
+	unsigned long tmp = 0;
 	unsigned char val;
 	unsigned long flags;
 
@@ -686,7 +686,7 @@ static DEVICE_ATTR(hardware_switching, (S_IWUSR|S_IWGRP), NULL,
 static ssize_t store_refalign (struct device *d,
 		 struct device_attribute *attr, const char *buf, size_t count)
 {
-	unsigned long tmp;
+	unsigned long tmp = 0;
 	unsigned long flags;
 
 	sscanf(buf, "%lX", &tmp);
@@ -705,7 +705,7 @@ static DEVICE_ATTR(refalign, (S_IWUSR|S_IWGRP), NULL, store_refalign);
 static ssize_t store_mode_select (struct device *d,
 		 struct device_attribute *attr, const char *buf, size_t count)
 {
-	unsigned long tmp;
+	unsigned long tmp = 0;
 	unsigned char val;
 	unsigned long flags;
 
@@ -725,7 +725,7 @@ static DEVICE_ATTR(mode_select, (S_IWUSR|S_IWGRP), NULL, store_mode_select);
 static ssize_t store_reset (struct device *d,
 		 struct device_attribute *attr, const char *buf, size_t count)
 {
-	unsigned long tmp;
+	unsigned long tmp = 0;
 	unsigned char val;
 	unsigned long flags;
 
-- 
2.54.0