From 7fcaec0b2ab8fa5fbf0b45e5512364a168f445bd Mon Sep 17 00:00:00 2001 From: Ilya Maximets Date: Sat, 12 Apr 2025 12:40:18 +0200 Subject: [PATCH] net: openvswitch: fix nested key length validation in the set() action [ Upstream commit 65d91192aa66f05710cfddf6a14b5a25ee554dba ] It's not safe to access nla_len(ovs_key) if the data is smaller than the netlink header. Check that the attribute is OK first. Fixes: ccb1352e76cf ("net: Add Open vSwitch kernel components.") Reported-by: syzbot+b07a9da40df1576b8048@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=b07a9da40df1576b8048 Tested-by: syzbot+b07a9da40df1576b8048@syzkaller.appspotmail.com Signed-off-by: Ilya Maximets Reviewed-by: Eelco Chaudron Acked-by: Aaron Conole Link: https://patch.msgid.link/20250412104052.2073688-1-i.maximets@ovn.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/openvswitch/flow_netlink.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c index cff18a5bbf386..3f8f43dbf44fc 100644 --- a/net/openvswitch/flow_netlink.c +++ b/net/openvswitch/flow_netlink.c @@ -2834,7 +2834,8 @@ static int validate_set(const struct nlattr *a, size_t key_len; /* There can be only one key in a action */ - if (nla_total_size(nla_len(ovs_key)) != nla_len(a)) + if (!nla_ok(ovs_key, nla_len(a)) || + nla_total_size(nla_len(ovs_key)) != nla_len(a)) return -EINVAL; key_len = nla_len(ovs_key); -- 2.47.3