[PATCH 4.6 15/81] net: hwbm: Fix unbalanced spinlock in error case

[Greg Kroah-Hartman]

4.6-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>

[ Upstream commit b388fc7405e901c7d6f7817d05193c054e761815 ]

When hwbm_pool_add exited in error the spinlock was not released. This
patch fixes this issue.

Fixes: 8cb2d8bf57e6 ("net: add a hardware buffer management helper API")
Reported-by: Jean-Jacques Hiblot <jjhiblot@xxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 net/core/hwbm.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/net/core/hwbm.c
+++ b/net/core/hwbm.c
@@ -55,18 +55,21 @@ int hwbm_pool_add(struct hwbm_pool *bm_p
 	spin_lock_irqsave(&bm_pool->lock, flags);
 	if (bm_pool->buf_num == bm_pool->size) {
 		pr_warn("pool already filled\n");
+		spin_unlock_irqrestore(&bm_pool->lock, flags);
 		return bm_pool->buf_num;
 	}
 
 	if (buf_num + bm_pool->buf_num > bm_pool->size) {
 		pr_warn("cannot allocate %d buffers for pool\n",
 			buf_num);
+		spin_unlock_irqrestore(&bm_pool->lock, flags);
 		return 0;
 	}
 
 	if ((buf_num + bm_pool->buf_num) < bm_pool->buf_num) {
 		pr_warn("Adding %d buffers to the %d current buffers will overflow\n",
 			buf_num,  bm_pool->buf_num);
+		spin_unlock_irqrestore(&bm_pool->lock, flags);
 		return 0;
 	}