net: ieee802154: fix nl802154 del llsec dev

commit 3d1eac2f45585690d942cf47fd7fbd04093ebd1b upstream.

This patch fixes a nullpointer dereference if NL802154_ATTR_SEC_DEVICE is
not set by the user. If this is the case nl802154 will return -EINVAL.

Reported-by: syzbot+d946223c2e751d136c94@syzkaller.appspotmail.com
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20210221174321.14210-2-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 6962ef1297c3b29ddf4cfe61747c2357b1e412c2..d07b6d1b0e3223347c7c3cc89a11b9419411e6fe 100644 (file)
--- a/net/ieee802154/nl802154.c
+++ b/net/ieee802154/nl802154.c
@@ -1746,7 +1746,8 @@ static int nl802154_del_llsec_dev(struct sk_buff *skb, struct genl_info *info)
        struct nlattr *attrs[NL802154_DEV_ATTR_MAX + 1];
        __le64 extended_addr;
 
-       if (nla_parse_nested(attrs, NL802154_DEV_ATTR_MAX,
+       if (!info->attrs[NL802154_ATTR_SEC_DEVICE] ||
+           nla_parse_nested(attrs, NL802154_DEV_ATTR_MAX,
                             info->attrs[NL802154_ATTR_SEC_DEVICE],
                             nl802154_dev_policy))
                return -EINVAL;