diff --git a/drivers/net/tun.c b/drivers/net/tun.c index a6c9f9062dbd4724e3b5e30a05da9d7483968d1e..03478ae3ff244819dca751353ddeab2a2e0eff29 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -574,18 +574,14 @@ static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb, return ret; } -static inline bool tun_capable(struct tun_struct *tun) +static inline bool tun_not_capable(struct tun_struct *tun) { const struct cred *cred = current_cred(); struct net *net = dev_net(tun->dev); - if (ns_capable(net->user_ns, CAP_NET_ADMIN)) - return 1; - if (uid_valid(tun->owner) && uid_eq(cred->euid, tun->owner)) - return 1; - if (gid_valid(tun->group) && in_egroup_p(tun->group)) - return 1; - return 0; + return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) || + (gid_valid(tun->group) && !in_egroup_p(tun->group))) && + !ns_capable(net->user_ns, CAP_NET_ADMIN); } static void tun_set_real_num_queues(struct tun_struct *tun) @@ -2771,7 +2767,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) !!(tun->flags & IFF_MULTI_QUEUE)) return -EINVAL; - if (!tun_capable(tun)) + if (tun_not_capable(tun)) return -EPERM; err = security_tun_dev_open(tun->security); if (err < 0)