[PATCH 5.11 202/210] net: ieee802154: nl-mac: fix check on panid

Greg Kroah-Hartman
2021-04-12T09:43:37Z

From: Alexander Aring <aahringo@redhat.com>

commit 6f7f657f24405f426212c09260bf7fe8a52cef33 upstream.

This patch fixes a null pointer derefence for panid handle by move the
check for the netlink variable directly before accessing them.

Reported-by: syzbot+d4c07de0144f6f63be3a@syzkaller.appspotmail.com
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20210228151817.95700-4-aahringo@redhat.com
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/ieee802154/nl-mac.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

--- a/net/ieee802154/nl-mac.c
+++ b/net/ieee802154/nl-mac.c
@@ -551,9 +551,7 @@ ieee802154_llsec_parse_key_id(struct gen
desc->mode = nla_get_u8(info->attrs[IEEE802154_ATTR_LLSEC_KEY_MODE]);

if (desc->mode == IEEE802154_SCF_KEY_IMPLICIT) {
- if (!info->attrs[IEEE802154_ATTR_PAN_ID] &&
- !(info->attrs[IEEE802154_ATTR_SHORT_ADDR] ||
- info->attrs[IEEE802154_ATTR_HW_ADDR]))
+ if (!info->attrs[IEEE802154_ATTR_PAN_ID])
return -EINVAL;

desc->device_addr.pan_id = nla_get_shortaddr(info->attrs[IEEE802154_ATTR_PAN_ID]);
@@ -562,6 +560,9 @@ ieee802154_llsec_parse_key_id(struct gen
desc->device_addr.mode = IEEE802154_ADDR_SHORT;
desc->device_addr.short_addr = nla_get_shortaddr(info->attrs[IEEE802154_ATTR_SHORT_ADDR]);
} else {
+ if (!info->attrs[IEEE802154_ATTR_HW_ADDR])
+ return -EINVAL;
+
desc->device_addr.mode = IEEE802154_ADDR_LONG;
desc->device_addr.extended_addr = nla_get_hwaddr(info->attrs[IEEE802154_ATTR_HW_ADDR]);
}