From: Eric Dumazet <edumazet@google.com>
Date: Mon, 6 Jul 2015 15:13:26 +0000 (+0200)
Subject: net: graceful exit from netif_alloc_netdev_queues()
X-Git-Tag: v4.1.9~45
X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bd60ae48f727ef6cb9b0524fb49b7336cbb0ca66;p=linux

net: graceful exit from netif_alloc_netdev_queues()

[ 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 <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/net/core/dev.c b/net/core/dev.c
index aa82f9ab6a36..47239143b48e 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6297,7 +6297,8 @@ 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) {