From: Lin Ma <linma@xxxxxxxxxx>
[ Upstream commit 55cef78c244d0d076f5a75a35530ca63c92f4426 ]
The previous commit 954d1fa1ac93 ("macvlan: Add netlink attribute for
broadcast cutoff") added one additional attribute named
IFLA_MACVLAN_BC_CUTOFF to allow broadcast cutfoff.
However, it forgot to describe the nla_policy at macvlan_policy
(drivers/net/macvlan.c). Hence, this suppose NLA_S32 (4 bytes) integer
can be faked as empty (0 bytes) by a malicious user, which could leads
to OOB in heap just like CVE-2023-3773.
To fix it, this commit just completes the nla_policy description for
IFLA_MACVLAN_BC_CUTOFF. This enforces the length check and avoids the
potential OOB read.
Fixes: 954d1fa1ac93 ("macvlan: Add netlink attribute for broadcast cutoff")
Signed-off-by: Lin Ma <linma@xxxxxxxxxx>
Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230723080205.3715164-1-linma@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/macvlan.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 4a53debf9d7c4..ed908165a8b4e 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -1746,6 +1746,7 @@ static const struct nla_policy macvlan_policy[IFLA_MACVLAN_MAX + 1] = {
[IFLA_MACVLAN_MACADDR_COUNT] = { .type = NLA_U32 },
[IFLA_MACVLAN_BC_QUEUE_LEN] = { .type = NLA_U32 },
[IFLA_MACVLAN_BC_QUEUE_LEN_USED] = { .type = NLA_REJECT },
+ [IFLA_MACVLAN_BC_CUTOFF] = { .type = NLA_S32 },
};
int macvlan_link_register(struct rtnl_link_ops *ops)
--
2.39.2
