net: ieee802154: fix nl802154 del llsec devkey

commit 27c746869e1a135dffc2f2a80715bb7aa00445b4 upstream.

This patch fixes a nullpointer dereference if NL802154_ATTR_SEC_DEVKEY is
not set by the user. If this is the case nl802154 will return -EINVAL.

Reported-by: syzbot+368672e0da240db53b5f@syzkaller.appspotmail.com
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20210221174321.14210-4-aahringo@redhat.com
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/ieee802154/nl802154.c b/net/ieee802154/nl802154.c
index 3f6d86d63923bfb5cb89405f2abb92fda8afe162..e9e4652cd592c7158a89e111c6dcf21e1ad7d10f 100644 (file)
--- a/net/ieee802154/nl802154.c
+++ b/net/ieee802154/nl802154.c
@@ -1916,7 +1916,8 @@ static int nl802154_del_llsec_devkey(struct sk_buff *skb, struct genl_info *info
        struct ieee802154_llsec_device_key key;
        __le64 extended_addr;
 
-       if (nla_parse_nested_deprecated(attrs, NL802154_DEVKEY_ATTR_MAX, info->attrs[NL802154_ATTR_SEC_DEVKEY], nl802154_devkey_policy, info->extack))
+       if (!info->attrs[NL802154_ATTR_SEC_DEVKEY] ||
+           nla_parse_nested_deprecated(attrs, NL802154_DEVKEY_ATTR_MAX, info->attrs[NL802154_ATTR_SEC_DEVKEY], nl802154_devkey_policy, info->extack))
                return -EINVAL;
 
        if (!attrs[NL802154_DEVKEY_ATTR_EXTENDED_ADDR])