From 2aba913f99debce6cd1c7f606d69d094d1202559 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 28 Feb 2024 13:54:37 +0000 Subject: ipv6/addrconf: annotate data-races around devconf fields (I) Annotate lockless reads and writes on following devconf fields: - regen_min_advance - regen_max_retry - dad_transmits - use_tempaddr - max_addresses - max_desync_factor - temp_valid_lft - rtr_solicits - rtr_solicit_max_interval - rtr_solicit_interval - rtr_solicit_delay - enhanced_dad - accept_redirects Signed-off-by: Eric Dumazet Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller --- net/ipv6/addrconf.c | 67 +++++++++++++++++++++++++++++------------------------ net/ipv6/route.c | 3 ++- 2 files changed, 39 insertions(+), 31 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 0e7135a206b0..bcfe725f8fbd 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -1359,11 +1359,12 @@ out: in6_ifa_put(ifp); } -static unsigned long ipv6_get_regen_advance(struct inet6_dev *idev) +static unsigned long ipv6_get_regen_advance(const struct inet6_dev *idev) { - return idev->cnf.regen_min_advance + idev->cnf.regen_max_retry * - idev->cnf.dad_transmits * - max(NEIGH_VAR(idev->nd_parms, RETRANS_TIME), HZ/100) / HZ; + return READ_ONCE(idev->cnf.regen_min_advance) + + READ_ONCE(idev->cnf.regen_max_retry) * + READ_ONCE(idev->cnf.dad_transmits) * + max(NEIGH_VAR(idev->nd_parms, RETRANS_TIME), HZ/100) / HZ; } static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp, bool block) @@ -1384,7 +1385,7 @@ static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp, bool block) retry: in6_dev_hold(idev); - if (idev->cnf.use_tempaddr <= 0) { + if (READ_ONCE(idev->cnf.use_tempaddr) <= 0) { write_unlock_bh(&idev->lock); pr_info("%s: use_tempaddr is disabled\n", __func__); in6_dev_put(idev); @@ -1392,8 +1393,8 @@ retry: goto out; } spin_lock_bh(&ifp->lock); - if (ifp->regen_count++ >= idev->cnf.regen_max_retry) { - idev->cnf.use_tempaddr = -1; /*XXX*/ + if (ifp->regen_count++ >= READ_ONCE(idev->cnf.regen_max_retry)) { + WRITE_ONCE(idev->cnf.use_tempaddr, -1); /*XXX*/ spin_unlock_bh(&ifp->lock); write_unlock_bh(&idev->lock); pr_warn("%s: regeneration time exceeded - disabled temporary address support\n", @@ -1415,7 +1416,7 @@ retry: */ cnf_temp_preferred_lft = READ_ONCE(idev->cnf.temp_prefered_lft); max_desync_factor = min_t(long, - idev->cnf.max_desync_factor, + READ_ONCE(idev->cnf.max_desync_factor), cnf_temp_preferred_lft - regen_advance); if (unlikely(idev->desync_factor > max_desync_factor)) { @@ -1432,7 +1433,7 @@ retry: memset(&cfg, 0, sizeof(cfg)); cfg.valid_lft = min_t(__u32, ifp->valid_lft, - idev->cnf.temp_valid_lft + age); + READ_ONCE(idev->cnf.temp_valid_lft) + age); cfg.preferred_lft = cnf_temp_preferred_lft + age - idev->desync_factor; cfg.preferred_lft = min_t(__u32, if_public_preferred_lft, cfg.preferred_lft); cfg.preferred_lft = min_t(__u32, cfg.valid_lft, cfg.preferred_lft); @@ -1685,7 +1686,7 @@ static int ipv6_get_saddr_eval(struct net *net, */ int preftmp = dst->prefs & (IPV6_PREFER_SRC_PUBLIC|IPV6_PREFER_SRC_TMP) ? !!(dst->prefs & IPV6_PREFER_SRC_TMP) : - score->ifa->idev->cnf.use_tempaddr >= 2; + READ_ONCE(score->ifa->idev->cnf.use_tempaddr) >= 2; ret = (!(score->ifa->flags & IFA_F_TEMPORARY)) ^ preftmp; break; } @@ -2168,6 +2169,7 @@ void addrconf_dad_failure(struct sk_buff *skb, struct inet6_ifaddr *ifp) { struct inet6_dev *idev = ifp->idev; struct net *net = dev_net(idev->dev); + int max_addresses; if (addrconf_dad_end(ifp)) { in6_ifa_put(ifp); @@ -2205,9 +2207,9 @@ void addrconf_dad_failure(struct sk_buff *skb, struct inet6_ifaddr *ifp) spin_unlock_bh(&ifp->lock); - if (idev->cnf.max_addresses && - ipv6_count_addresses(idev) >= - idev->cnf.max_addresses) + max_addresses = READ_ONCE(idev->cnf.max_addresses); + if (max_addresses && + ipv6_count_addresses(idev) >= max_addresses) goto lock_errdad; net_info_ratelimited("%s: generating new stable privacy address because of DAD conflict\n", @@ -2604,11 +2606,11 @@ static void manage_tempaddrs(struct inet6_dev *idev, * (TEMP_PREFERRED_LIFETIME - DESYNC_FACTOR), respectively. */ age = (now - ift->cstamp) / HZ; - max_valid = idev->cnf.temp_valid_lft - age; + max_valid = READ_ONCE(idev->cnf.temp_valid_lft) - age; if (max_valid < 0) max_valid = 0; - max_prefered = idev->cnf.temp_prefered_lft - + max_prefered = READ_ONCE(idev->cnf.temp_prefered_lft) - idev->desync_factor - age; if (max_prefered < 0) max_prefered = 0; @@ -2641,7 +2643,7 @@ static void manage_tempaddrs(struct inet6_dev *idev, if (list_empty(&idev->tempaddr_list) && (valid_lft || prefered_lft)) create = true; - if (create && idev->cnf.use_tempaddr > 0) { + if (create && READ_ONCE(idev->cnf.use_tempaddr) > 0) { /* When a new public address is created as described * in [ADDRCONF], also create a new temporary address. */ @@ -2669,7 +2671,7 @@ int addrconf_prefix_rcv_add_addr(struct net *net, struct net_device *dev, int create = 0, update_lft = 0; if (!ifp && valid_lft) { - int max_addresses = in6_dev->cnf.max_addresses; + int max_addresses = READ_ONCE(in6_dev->cnf.max_addresses); struct ifa6_config cfg = { .pfx = addr, .plen = pinfo->prefix_len, @@ -4028,6 +4030,7 @@ static void addrconf_rs_timer(struct timer_list *t) struct inet6_dev *idev = from_timer(idev, t, rs_timer); struct net_device *dev = idev->dev; struct in6_addr lladdr; + int rtr_solicits; write_lock(&idev->lock); if (idev->dead || !(idev->if_flags & IF_READY)) @@ -4040,7 +4043,9 @@ static void addrconf_rs_timer(struct timer_list *t) if (idev->if_flags & IF_RA_RCVD) goto out; - if (idev->rs_probes++ < idev->cnf.rtr_solicits || idev->cnf.rtr_solicits < 0) { + rtr_solicits = READ_ONCE(idev->cnf.rtr_solicits); + + if (idev->rs_probes++ < rtr_solicits || rtr_solicits < 0) { write_unlock(&idev->lock); if (!ipv6_get_lladdr(dev, &lladdr, IFA_F_TENTATIVE)) ndisc_send_rs(dev, &lladdr, @@ -4050,11 +4055,12 @@ static void addrconf_rs_timer(struct timer_list *t) write_lock(&idev->lock); idev->rs_interval = rfc3315_s14_backoff_update( - idev->rs_interval, idev->cnf.rtr_solicit_max_interval); + idev->rs_interval, + READ_ONCE(idev->cnf.rtr_solicit_max_interval)); /* The wait after the last probe can be shorter */ addrconf_mod_rs_timer(idev, (idev->rs_probes == - idev->cnf.rtr_solicits) ? - idev->cnf.rtr_solicit_delay : + READ_ONCE(idev->cnf.rtr_solicits)) ? + READ_ONCE(idev->cnf.rtr_solicit_delay) : idev->rs_interval); } else { /* @@ -4075,24 +4081,25 @@ put: */ static void addrconf_dad_kick(struct inet6_ifaddr *ifp) { - unsigned long rand_num; struct inet6_dev *idev = ifp->idev; + unsigned long rand_num; u64 nonce; if (ifp->flags & IFA_F_OPTIMISTIC) rand_num = 0; else - rand_num = get_random_u32_below(idev->cnf.rtr_solicit_delay ? : 1); + rand_num = get_random_u32_below( + READ_ONCE(idev->cnf.rtr_solicit_delay) ? : 1); nonce = 0; - if (idev->cnf.enhanced_dad || - dev_net(idev->dev)->ipv6.devconf_all->enhanced_dad) { + if (READ_ONCE(idev->cnf.enhanced_dad) || + READ_ONCE(dev_net(idev->dev)->ipv6.devconf_all->enhanced_dad)) { do get_random_bytes(&nonce, 6); while (nonce == 0); } ifp->dad_nonce = nonce; - ifp->dad_probes = idev->cnf.dad_transmits; + ifp->dad_probes = READ_ONCE(idev->cnf.dad_transmits); addrconf_mod_dad_work(ifp, rand_num); } @@ -4331,7 +4338,7 @@ static void addrconf_dad_completed(struct inet6_ifaddr *ifp, bool bump_id, send_mld = ifp->scope == IFA_LINK && ipv6_lonely_lladdr(ifp); send_rs = send_mld && ipv6_accept_ra(ifp->idev) && - ifp->idev->cnf.rtr_solicits != 0 && + READ_ONCE(ifp->idev->cnf.rtr_solicits) != 0 && (dev->flags & IFF_LOOPBACK) == 0 && (dev->type != ARPHRD_TUNNEL) && !netif_is_team_port(dev); @@ -4366,7 +4373,7 @@ static void addrconf_dad_completed(struct inet6_ifaddr *ifp, bool bump_id, write_lock_bh(&ifp->idev->lock); spin_lock(&ifp->lock); ifp->idev->rs_interval = rfc3315_s14_backoff_init( - ifp->idev->cnf.rtr_solicit_interval); + READ_ONCE(ifp->idev->cnf.rtr_solicit_interval)); ifp->idev->rs_probes = 1; ifp->idev->if_flags |= IF_RS_SENT; addrconf_mod_rs_timer(ifp->idev, ifp->idev->rs_interval); @@ -5915,7 +5922,7 @@ static int inet6_set_iftoken(struct inet6_dev *idev, struct in6_addr *token, return -EINVAL; } - if (idev->cnf.rtr_solicits == 0) { + if (READ_ONCE(idev->cnf.rtr_solicits) == 0) { NL_SET_ERR_MSG(extack, "Router solicitation is disabled on device"); return -EINVAL; @@ -5948,7 +5955,7 @@ update_lft: if (update_rs) { idev->if_flags |= IF_RS_SENT; idev->rs_interval = rfc3315_s14_backoff_init( - idev->cnf.rtr_solicit_interval); + READ_ONCE(idev->cnf.rtr_solicit_interval)); idev->rs_probes = 1; addrconf_mod_rs_timer(idev, idev->rs_interval); } diff --git a/net/ipv6/route.c b/net/ipv6/route.c index a92fcac902ae..2cecb1c5a58f 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -4150,7 +4150,8 @@ static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_bu in6_dev = __in6_dev_get(skb->dev); if (!in6_dev) return; - if (READ_ONCE(in6_dev->cnf.forwarding) || !in6_dev->cnf.accept_redirects) + if (READ_ONCE(in6_dev->cnf.forwarding) || + !READ_ONCE(in6_dev->cnf.accept_redirects)) return; /* RFC2461 8.1: -- cgit