diag: Add NULL checks for the mask and mask pointer

The chances of accessing uninitialized mask is prevented
by adding null pointer checks for the mask structure and its
member pointer.

Change-Id: Ibf0467228794b773fc2537d34f1da6719bbb975a
Signed-off-by: Manoj Prabhu B <bmanoj@codeaurora.org>

2 files changed, 22 insertions, 5 deletions

diff --git a/drivers/char/diag/diag_masks.c b/drivers/char/diag/diag_masks.c
index 94613a47eafa..2a5d1aa3a190 100644
--- a/drivers/char/diag/diag_masks.c
+++ b/drivers/char/diag/diag_masks.c
@@ -171,6 +171,9 @@ static void diag_send_log_mask_update(uint8_t peripheral, int equip_id)
 
 	mutex_lock(&mask_info->lock);
 	for (i = 0; i < MAX_EQUIP_ID; i++, mask++) {
+		if (!mask->ptr)
+			continue;
+
 		if (equip_id != i && equip_id != ALL_EQUIP_ID)
 			continue;
 
@@ -400,6 +403,8 @@ static void diag_send_msg_mask_update(uint8_t peripheral, int first, int last)
 	}
 
 	for (i = 0; i < msg_mask_tbl_count_local; i++, mask++) {
+		if (!mask->ptr)
+			continue;
 		mutex_lock(&driver->msg_mask_lock);
 		if (((mask->ssid_first > first) ||
 			(mask->ssid_last_tools < last)) && first != ALL_SSID) {
@@ -644,6 +649,8 @@ static int diag_cmd_get_build_mask(unsigned char *src_buf, int src_len,
 	rsp.padding = 0;
 	build_mask = (struct diag_msg_mask_t *)msg_bt_mask.ptr;
 	for (i = 0; i < driver->bt_msg_mask_tbl_count; i++, build_mask++) {
+		if (!build_mask->ptr)
+			continue;
 		if (build_mask->ssid_first != req->ssid_first)
 			continue;
 		num_entries = req->ssid_last - req->ssid_first + 1;
@@ -720,6 +727,8 @@ static int diag_cmd_get_msg_mask(unsigned char *src_buf, int src_len,
 		return -EINVAL;
 	}
 	for (i = 0; i < driver->msg_mask_tbl_count; i++, mask++) {
+		if (!mask->ptr)
+			continue;
 		if ((req->ssid_first < mask->ssid_first) ||
 		    (req->ssid_first > mask->ssid_last_tools)) {
 			continue;
@@ -789,6 +798,8 @@ static int diag_cmd_set_msg_mask(unsigned char *src_buf, int src_len,
 		return -EINVAL;
 	}
 	for (i = 0; i < driver->msg_mask_tbl_count; i++, mask++) {
+		if (!mask->ptr)
+			continue;
 		if (i < (driver->msg_mask_tbl_count - 1)) {
 			mask_next = mask;
 			mask_next++;
@@ -1526,7 +1537,8 @@ static int diag_create_msg_mask_table(void)
 	mutex_lock(&msg_mask.lock);
 	mutex_lock(&driver->msg_mask_lock);
 	driver->msg_mask_tbl_count = MSG_MASK_TBL_CNT;
-	for (i = 0; i < driver->msg_mask_tbl_count; i++, mask++) {
+	for (i = 0; (i < driver->msg_mask_tbl_count) && mask;
+			i++, mask++) {
 		range.ssid_first = msg_mask_tbl[i].ssid_first;
 		range.ssid_last = msg_mask_tbl[i].ssid_last;
 		err = diag_create_msg_mask_table_entry(mask, &range);
@@ -1551,7 +1563,8 @@ static int diag_create_build_time_mask(void)
 	mutex_lock(&driver->msg_mask_lock);
 	driver->bt_msg_mask_tbl_count = MSG_MASK_TBL_CNT;
 	build_mask = (struct diag_msg_mask_t *)msg_bt_mask.ptr;
-	for (i = 0; i < driver->bt_msg_mask_tbl_count; i++, build_mask++) {
+	for (i = 0; (i < driver->bt_msg_mask_tbl_count) && build_mask;
+			i++, build_mask++) {
 		range.ssid_first = msg_mask_tbl[i].ssid_first;
 		range.ssid_last = msg_mask_tbl[i].ssid_last;
 		err = diag_create_msg_mask_table_entry(build_mask, &range);
@@ -1674,7 +1687,7 @@ static int diag_create_log_mask_table(void)
 
 	mutex_lock(&log_mask.lock);
 	mask = (struct diag_log_mask_t *)(log_mask.ptr);
-	for (i = 0; i < MAX_EQUIP_ID; i++, mask++) {
+	for (i = 0; (i < MAX_EQUIP_ID) && mask; i++, mask++) {
 		mask->equip_id = i;
 		mask->num_items = LOG_GET_ITEM_NUM(log_code_last_tbl[i]);
 		mask->num_items_tools = mask->num_items;
@@ -2069,6 +2082,8 @@ int diag_copy_to_user_msg_mask(char __user *buf, size_t count,
 		return -EINVAL;
 	}
 	for (i = 0; i < driver->msg_mask_tbl_count; i++, mask++) {
+		if (!mask->ptr)
+			continue;
 		ptr = mask_info->update_buf;
 		len = 0;
 		mutex_lock(&mask->lock);
@@ -2143,6 +2158,8 @@ int diag_copy_to_user_log_mask(char __user *buf, size_t count,
 		return -EINVAL;
 	}
 	for (i = 0; i < MAX_EQUIP_ID; i++, mask++) {
+		if (!mask->ptr)
+			continue;
 		ptr = mask_info->update_buf;
 		len = 0;
 		mutex_lock(&mask->lock);
diff --git a/drivers/char/diag/diagfwd_cntl.c b/drivers/char/diag/diagfwd_cntl.c
index 907bf6ee8511..8fb9227d8cb8 100644
--- a/drivers/char/diag/diagfwd_cntl.c
+++ b/drivers/char/diag/diagfwd_cntl.c
@@ -662,7 +662,7 @@ static void process_ssid_range_report(uint8_t *buf, uint32_t len,
 		mask_ptr = (struct diag_msg_mask_t *)msg_mask.ptr;
 		found = 0;
 		for (j = 0; j < driver->msg_mask_tbl_count; j++, mask_ptr++) {
-			if (!mask_ptr || !ssid_range) {
+			if (!mask_ptr->ptr || !ssid_range) {
 				found = 1;
 				break;
 			}
@@ -741,7 +741,7 @@ static void diag_build_time_mask_update(uint8_t *buf,
 	num_items = range->ssid_last - range->ssid_first + 1;
 
 	for (i = 0; i < driver->bt_msg_mask_tbl_count; i++, build_mask++) {
-		if (!build_mask) {
+		if (!build_mask->ptr) {
 			found = 1;
 			break;
 		}