Subject: [PATCH 02/21] net: graceful exit from netif_alloc_netdev_queues()

From: Eric Dumazet <[email-masked]>
Date: Mon, 6 Jul 2015 17:13:26 +0200

[ Upstream commit d339727c2b1a10f25e6636670ab6e1841170e328 ]

User space can crash kernel with

ip link add ifb10 numtxqueues 100000 type ifb

We must replace a BUG_ON() by proper test and return -EINVAL for
crazy values.

Fixes: 60877a32bce00 ("net: allow large number of tx queues")
Signed-off-by: Eric Dumazet <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 net/core/dev.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index 3ca487e..5a407f0 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5559,7 +5559,8 @@ static int netif_alloc_netdev_queues(struct net_device *dev)
 	struct netdev_queue *tx;
 	size_t sz = count * sizeof(*tx);
 
-	BUG_ON(count < 1 || count > 0xffff);
+	if (count < 1 || count > 0xffff)
+		return -EINVAL;
 
 	tx = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
 	if (!tx) {
-- 
2.1.0