[PATCH net-next 5/9] net: do not advance stack index from dev_fwd_path()

[Pablo Neira Ayuso <pablo@netfilter.org>]

Update stack index from dev_fill_forward_path() instead, once the
forward path slot has been populated.

Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/core/dev.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index c1c1be1a6962..429a55fff667 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -742,12 +742,10 @@ EXPORT_SYMBOL_GPL(dev_fill_metadata_dst);
 
 static struct net_device_path *dev_fwd_path(struct net_device_path_stack *stack)
 {
-	int k = stack->num_paths++;
-
-	if (k >= NET_DEVICE_PATH_STACK_MAX)
+	if (stack->num_paths + 1 > NET_DEVICE_PATH_STACK_MAX)
 		return NULL;
 
-	return &stack->path[k];
+	return &stack->path[stack->num_paths];
 }
 
 int dev_fill_forward_path(const struct net_device *dev, const u8 *daddr,
@@ -773,6 +771,7 @@ int dev_fill_forward_path(const struct net_device *dev, const u8 *daddr,
 		if (ret < 0)
 			return -1;
 
+		stack->num_paths++;
 		if (WARN_ON_ONCE(last_dev == ctx.dev))
 			return -1;
 	}
@@ -785,6 +784,7 @@ int dev_fill_forward_path(const struct net_device *dev, const u8 *daddr,
 		return -1;
 	path->type = DEV_PATH_ETHERNET;
 	path->dev = ctx.dev;
+	stack->num_paths++;
 
 	return ret;
 }
-- 
2.47.3