1 files changed, 76 insertions, 39 deletions

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index 682fcaec56e6..8c1710bba803 100644
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -32,6 +32,7 @@
 #include <linux/jiffies.h>
 #include <linux/list.h>
 #include <linux/kref.h>
+#include <linux/lockdep.h>
 #include <linux/netdevice.h>
 #include <linux/pkt_sched.h>
 #include <linux/printk.h>
@@ -175,71 +176,107 @@ unlock:
 }
 
 /**
- * batadv_iv_ogm_orig_del_if - change the private structures of the orig_node to
- *  exclude the removed interface
+ * batadv_iv_ogm_drop_bcast_own_entry - drop section of bcast_own
  * @orig_node: the orig_node that has to be changed
  * @max_if_num: the current amount of interfaces
  * @del_if_num: the index of the interface being removed
- *
- * Return: 0 on success, a negative error code otherwise.
  */
-static int batadv_iv_ogm_orig_del_if(struct batadv_orig_node *orig_node,
-				     int max_if_num, int del_if_num)
+static void
+batadv_iv_ogm_drop_bcast_own_entry(struct batadv_orig_node *orig_node,
+				   int max_if_num, int del_if_num)
 {
-	int ret = -ENOMEM;
-	size_t chunk_size, if_offset;
-	void *data_ptr = NULL;
-
-	spin_lock_bh(&orig_node->bat_iv.ogm_cnt_lock);
+	size_t chunk_size;
+	size_t if_offset;
+	void *data_ptr;
 
-	/* last interface was removed */
-	if (max_if_num == 0)
-		goto free_bcast_own;
+	lockdep_assert_held(&orig_node->bat_iv.ogm_cnt_lock);
 
 	chunk_size = sizeof(unsigned long) * BATADV_NUM_WORDS;
 	data_ptr = kmalloc_array(max_if_num, chunk_size, GFP_ATOMIC);
 	if (!data_ptr)
-		goto unlock;
+		/* use old buffer when new one could not be allocated */
+		data_ptr = orig_node->bat_iv.bcast_own;
 
 	/* copy first part */
-	memcpy(data_ptr, orig_node->bat_iv.bcast_own, del_if_num * chunk_size);
+	memmove(data_ptr, orig_node->bat_iv.bcast_own, del_if_num * chunk_size);
 
 	/* copy second part */
 	if_offset = (del_if_num + 1) * chunk_size;
-	memcpy((char *)data_ptr + del_if_num * chunk_size,
-	       (uint8_t *)orig_node->bat_iv.bcast_own + if_offset,
-	       (max_if_num - del_if_num) * chunk_size);
+	memmove((char *)data_ptr + del_if_num * chunk_size,
+		(uint8_t *)orig_node->bat_iv.bcast_own + if_offset,
+		(max_if_num - del_if_num) * chunk_size);
 
-free_bcast_own:
-	kfree(orig_node->bat_iv.bcast_own);
-	orig_node->bat_iv.bcast_own = data_ptr;
+	/* bcast_own was shrunk down in new buffer; free old one */
+	if (orig_node->bat_iv.bcast_own != data_ptr) {
+		kfree(orig_node->bat_iv.bcast_own);
+		orig_node->bat_iv.bcast_own = data_ptr;
+	}
+}
+
+/**
+ * batadv_iv_ogm_drop_bcast_own_sum_entry - drop section of bcast_own_sum
+ * @orig_node: the orig_node that has to be changed
+ * @max_if_num: the current amount of interfaces
+ * @del_if_num: the index of the interface being removed
+ */
+static void
+batadv_iv_ogm_drop_bcast_own_sum_entry(struct batadv_orig_node *orig_node,
+				       int max_if_num, int del_if_num)
+{
+	size_t if_offset;
+	void *data_ptr;
 
-	if (max_if_num == 0)
-		goto free_own_sum;
+	lockdep_assert_held(&orig_node->bat_iv.ogm_cnt_lock);
 
 	data_ptr = kmalloc_array(max_if_num, sizeof(u8), GFP_ATOMIC);
-	if (!data_ptr) {
-		kfree(orig_node->bat_iv.bcast_own);
-		goto unlock;
-	}
+	if (!data_ptr)
+		/* use old buffer when new one could not be allocated */
+		data_ptr = orig_node->bat_iv.bcast_own_sum;
 
-	memcpy(data_ptr, orig_node->bat_iv.bcast_own_sum,
-	       del_if_num * sizeof(u8));
+	memmove(data_ptr, orig_node->bat_iv.bcast_own_sum,
+		del_if_num * sizeof(u8));
 
 	if_offset = (del_if_num + 1) * sizeof(u8);
-	memcpy((char *)data_ptr + del_if_num * sizeof(u8),
-	       orig_node->bat_iv.bcast_own_sum + if_offset,
-	       (max_if_num - del_if_num) * sizeof(u8));
+	memmove((char *)data_ptr + del_if_num * sizeof(u8),
+		orig_node->bat_iv.bcast_own_sum + if_offset,
+		(max_if_num - del_if_num) * sizeof(u8));
+
+	/* bcast_own_sum was shrunk down in new buffer; free old one */
+	if (orig_node->bat_iv.bcast_own_sum != data_ptr) {
+		kfree(orig_node->bat_iv.bcast_own_sum);
+		orig_node->bat_iv.bcast_own_sum = data_ptr;
+	}
+}
 
-free_own_sum:
-	kfree(orig_node->bat_iv.bcast_own_sum);
-	orig_node->bat_iv.bcast_own_sum = data_ptr;
+/**
+ * batadv_iv_ogm_orig_del_if - change the private structures of the orig_node to
+ *  exclude the removed interface
+ * @orig_node: the orig_node that has to be changed
+ * @max_if_num: the current amount of interfaces
+ * @del_if_num: the index of the interface being removed
+ *
+ * Return: 0 on success, a negative error code otherwise.
+ */
+static int batadv_iv_ogm_orig_del_if(struct batadv_orig_node *orig_node,
+				     int max_if_num, int del_if_num)
+{
+	spin_lock_bh(&orig_node->bat_iv.ogm_cnt_lock);
+
+	if (max_if_num == 0) {
+		kfree(orig_node->bat_iv.bcast_own);
+		kfree(orig_node->bat_iv.bcast_own_sum);
+		orig_node->bat_iv.bcast_own = NULL;
+		orig_node->bat_iv.bcast_own_sum = NULL;
+	} else {
+		batadv_iv_ogm_drop_bcast_own_entry(orig_node, max_if_num,
+						   del_if_num);
+		batadv_iv_ogm_drop_bcast_own_sum_entry(orig_node, max_if_num,
+						       del_if_num);
+	}
 
-	ret = 0;
-unlock:
 	spin_unlock_bh(&orig_node->bat_iv.ogm_cnt_lock);
 
-	return ret;
+	return 0;
 }
 
 /**