Re: [PATCH wpan 01/17] net: ieee802154: make shift exponent unsigned
From: Stefan Schmidt <stefan@datenfreihafen.org>
Date: 2021-03-03 04:23:58
Hello Alex. On 28.02.21 16:18, Alexander Aring wrote:
quoted hunk ↗ jump to hunk
This patch changes the iftype type variable to unsigned that it can never be reach a negative value. Reported-by: syzbot+7bf7b22759195c9a21e9@syzkaller.appspotmail.com Signed-off-by: Alexander Aring <aahringo@redhat.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 e9e4652cd592..3ee09f6d13b7 100644 --- a/net/ieee802154/nl802154.c +++ b/net/ieee802154/nl802154.c@@ -898,8 +898,8 @@ static int nl802154_get_interface(struct sk_buff *skb, struct genl_info *info) static int nl802154_new_interface(struct sk_buff *skb, struct genl_info *info) { struct cfg802154_registered_device *rdev = info->user_ptr[0]; - enum nl802154_iftype type = NL802154_IFTYPE_UNSPEC; __le64 extended_addr = cpu_to_le64(0x0000000000000000ULL); + u32 type = NL802154_IFTYPE_UNSPEC; /* TODO avoid failing a new interface * creation due to pending removal?
I am concerned about this one. Maybe you can shed some light on it. NL802154_IFTYPE_UNSPEC is -1 which means the u32 will not hold this value, but something at the end of the range for u32. There is a path (info->attrs[NL802154_ATTR_IFTYPE] is not true) where we put type forward to rdev_add_virtual_intf() with its changed value but it would expect and enum which could hold -1 for UNSPEC. regards Stefan Schmidt