From:   Dongliang Mu <mudongliangabcd@gmail.com>
To:     Alexander Aring <alex.aring@gmail.com>,
        Stefan Schmidt <stefan@datenfreihafen.org>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Marcel Holtmann <marcel@holtmann.org>
Cc:     Dongliang Mu <mudongliangabcd@gmail.com>,
        linux-wpan@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH v2] net: ieee802154: fix shift-out-of-bound in nl802154_new_interface
Date:   Thu, 11 Nov 2021 22:58:46 +0800
Message-Id: <20211111145847.1487241-1-mudongliangabcd@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

In nl802154_new_interface, if type retrieved from info->attr is
NL802154_IFTYPE_UNSPEC(-1), i.e., less than NL802154_IFTYPE_MAX,
it will trigger a shift-out-of-bound bug in BIT(type) [1].

Fix this by adding a condition to check if the variable type is
larger than NL802154_IFTYPE_UNSPEC(-1).

Fixes: 65318680c97c ("ieee802154: add iftypes capability")
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
---
 net/ieee802154/nl802154.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ieee802154/nl802154.c b/net/ieee802154/nl802154.c
index 277124f206e0..0613867d43ce 100644
--- a/net/ieee802154/nl802154.c
+++ b/net/ieee802154/nl802154.c
@@ -915,7 +915,7 @@ static int nl802154_new_interface(struct sk_buff *skb, struct genl_info *info)
 
 	if (info->attrs[NL802154_ATTR_IFTYPE]) {
 		type = nla_get_u32(info->attrs[NL802154_ATTR_IFTYPE]);
-		if (type > NL802154_IFTYPE_MAX ||
+		if (type <= NL802154_IFTYPE_UNSPEC || type > NL802154_IFTYPE_MAX ||
 		    !(rdev->wpan_phy.supported.iftypes & BIT(type)))
 			return -EINVAL;
 	}
-- 
2.25.1