6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet edumazet@google.com
[ Upstream commit 1caf27297215a5241f9bfc9c07336349d9034ee3 ]
Use the new helper as a step to deal with potential dst->dev races.
Signed-off-by: Eric Dumazet edumazet@google.com Reviewed-by: Kuniyuki Iwashima kuniyu@google.com Link: https://patch.msgid.link/20250630121934.3399505-9-edumazet@google.com Signed-off-by: Jakub Kicinski kuba@kernel.org [Harshit: Backport to 6.12.y, pulled this is a prerequisite] Stable-dep-of: 99a2ace61b21 ("net: use dst_dev_rcu() in sk_setup_caps()") Signed-off-by: Harshit Mogalapalli harshit.m.mogalapalli@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/net/ip6_route.h | 4 ++-- net/ipv6/exthdrs.c | 2 +- net/ipv6/icmp.c | 4 +++- net/ipv6/ila/ila_lwt.c | 2 +- net/ipv6/ioam6_iptunnel.c | 4 ++-- net/ipv6/ip6_gre.c | 8 +++++--- net/ipv6/ip6_output.c | 19 ++++++++++--------- net/ipv6/ip6_tunnel.c | 4 ++-- net/ipv6/ip6_udp_tunnel.c | 2 +- net/ipv6/ip6_vti.c | 2 +- net/ipv6/ndisc.c | 6 ++++-- net/ipv6/netfilter/nf_dup_ipv6.c | 2 +- net/ipv6/output_core.c | 2 +- net/ipv6/route.c | 20 ++++++++++++-------- net/ipv6/rpl_iptunnel.c | 4 ++-- net/ipv6/seg6_iptunnel.c | 20 +++++++++++--------- net/ipv6/seg6_local.c | 2 +- 17 files changed, 60 insertions(+), 47 deletions(-)
--- a/include/net/ip6_route.h +++ b/include/net/ip6_route.h @@ -274,7 +274,7 @@ static inline unsigned int ip6_skb_dst_m unsigned int mtu;
if (np && READ_ONCE(np->pmtudisc) >= IPV6_PMTUDISC_PROBE) { - mtu = READ_ONCE(dst->dev->mtu); + mtu = READ_ONCE(dst_dev(dst)->mtu); mtu -= lwtunnel_headroom(dst->lwtstate, mtu); } else { mtu = dst_mtu(dst); @@ -337,7 +337,7 @@ static inline unsigned int ip6_dst_mtu_m
mtu = IPV6_MIN_MTU; rcu_read_lock(); - idev = __in6_dev_get(dst->dev); + idev = __in6_dev_get(dst_dev(dst)); if (idev) mtu = READ_ONCE(idev->cnf.mtu6); rcu_read_unlock(); --- a/net/ipv6/exthdrs.c +++ b/net/ipv6/exthdrs.c @@ -306,7 +306,7 @@ static int ipv6_destopt_rcv(struct sk_bu if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) || !pskb_may_pull(skb, (skb_transport_offset(skb) + ((skb_transport_header(skb)[1] + 1) << 3)))) { - __IP6_INC_STATS(dev_net(dst->dev), idev, + __IP6_INC_STATS(dev_net(dst_dev(dst)), idev, IPSTATS_MIB_INHDRERRORS); fail_and_free: kfree_skb(skb); --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -196,6 +196,7 @@ static bool icmpv6_xrlim_allow(struct so struct flowi6 *fl6, bool apply_ratelimit) { struct net *net = sock_net(sk); + struct net_device *dev; struct dst_entry *dst; bool res = false;
@@ -208,10 +209,11 @@ static bool icmpv6_xrlim_allow(struct so * this lookup should be more aggressive (not longer than timeout). */ dst = ip6_route_output(net, sk, fl6); + dev = dst_dev(dst); if (dst->error) { IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); - } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) { + } else if (dev && (dev->flags & IFF_LOOPBACK)) { res = true; } else { struct rt6_info *rt = dst_rt6_info(dst); --- a/net/ipv6/ila/ila_lwt.c +++ b/net/ipv6/ila/ila_lwt.c @@ -70,7 +70,7 @@ static int ila_output(struct net *net, s */
memset(&fl6, 0, sizeof(fl6)); - fl6.flowi6_oif = orig_dst->dev->ifindex; + fl6.flowi6_oif = dst_dev(orig_dst)->ifindex; fl6.flowi6_iif = LOOPBACK_IFINDEX; fl6.daddr = *rt6_nexthop(dst_rt6_info(orig_dst), &ip6h->daddr); --- a/net/ipv6/ioam6_iptunnel.c +++ b/net/ipv6/ioam6_iptunnel.c @@ -328,7 +328,7 @@ static int ioam6_do_encap(struct net *ne if (has_tunsrc) memcpy(&hdr->saddr, tunsrc, sizeof(*tunsrc)); else - ipv6_dev_get_saddr(net, dst->dev, &hdr->daddr, + ipv6_dev_get_saddr(net, dst_dev(dst), &hdr->daddr, IPV6_PREFER_SRC_PUBLIC, &hdr->saddr);
skb_postpush_rcsum(skb, hdr, len); @@ -417,7 +417,7 @@ do_encap: local_bh_enable(); }
- err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev)); + err = skb_cow_head(skb, LL_RESERVED_SPACE(dst_dev(dst))); if (unlikely(err)) goto drop; } --- a/net/ipv6/ip6_gre.c +++ b/net/ipv6/ip6_gre.c @@ -1084,9 +1084,11 @@ static netdev_tx_t ip6erspan_tunnel_xmit htonl(atomic_fetch_inc(&t->o_seqno)));
/* TooBig packet may have updated dst->dev's mtu */ - if (!t->parms.collect_md && dst && dst_mtu(dst) > dst->dev->mtu) - dst->ops->update_pmtu(dst, NULL, skb, dst->dev->mtu, false); - + if (!t->parms.collect_md && dst) { + mtu = READ_ONCE(dst_dev(dst)->mtu); + if (dst_mtu(dst) > mtu) + dst->ops->update_pmtu(dst, NULL, skb, mtu, false); + } err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu, NEXTHDR_GRE); if (err != 0) { --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -60,7 +60,7 @@ static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff *skb) { struct dst_entry *dst = skb_dst(skb); - struct net_device *dev = dst->dev; + struct net_device *dev = dst_dev(dst); struct inet6_dev *idev = ip6_dst_idev(dst); unsigned int hh_len = LL_RESERVED_SPACE(dev); const struct in6_addr *daddr, *nexthop; @@ -271,7 +271,7 @@ int ip6_xmit(const struct sock *sk, stru const struct ipv6_pinfo *np = inet6_sk(sk); struct in6_addr *first_hop = &fl6->daddr; struct dst_entry *dst = skb_dst(skb); - struct net_device *dev = dst->dev; + struct net_device *dev = dst_dev(dst); struct inet6_dev *idev = ip6_dst_idev(dst); struct hop_jumbo_hdr *hop_jumbo; int hoplen = sizeof(*hop_jumbo); @@ -503,7 +503,8 @@ int ip6_forward(struct sk_buff *skb) struct dst_entry *dst = skb_dst(skb); struct ipv6hdr *hdr = ipv6_hdr(skb); struct inet6_skb_parm *opt = IP6CB(skb); - struct net *net = dev_net(dst->dev); + struct net *net = dev_net(dst_dev(dst)); + struct net_device *dev; struct inet6_dev *idev; SKB_DR(reason); u32 mtu; @@ -591,12 +592,12 @@ int ip6_forward(struct sk_buff *skb) goto drop; } dst = skb_dst(skb); - + dev = dst_dev(dst); /* IPv6 specs say nothing about it, but it is clear that we cannot send redirects to source routed frames. We don't send redirects to frames decapsulated from IPsec. */ - if (IP6CB(skb)->iif == dst->dev->ifindex && + if (IP6CB(skb)->iif == dev->ifindex && opt->srcrt == 0 && !skb_sec_path(skb)) { struct in6_addr *target = NULL; struct inet_peer *peer; @@ -644,7 +645,7 @@ int ip6_forward(struct sk_buff *skb)
if (ip6_pkt_too_big(skb, mtu)) { /* Again, force OUTPUT device used as source address */ - skb->dev = dst->dev; + skb->dev = dev; icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); __IP6_INC_STATS(net, idev, IPSTATS_MIB_INTOOBIGERRORS); __IP6_INC_STATS(net, ip6_dst_idev(dst), @@ -653,7 +654,7 @@ int ip6_forward(struct sk_buff *skb) return -EMSGSIZE; }
- if (skb_cow(skb, dst->dev->hard_header_len)) { + if (skb_cow(skb, dev->hard_header_len)) { __IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTDISCARDS); goto drop; @@ -666,7 +667,7 @@ int ip6_forward(struct sk_buff *skb) hdr->hop_limit--;
return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD, - net, NULL, skb, skb->dev, dst->dev, + net, NULL, skb, skb->dev, dev, ip6_forward_finish);
error: @@ -1093,7 +1094,7 @@ static struct dst_entry *ip6_sk_dst_chec #ifdef CONFIG_IPV6_SUBTREES ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) || #endif - (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex)) { + (fl6->flowi6_oif && fl6->flowi6_oif != dst_dev(dst)->ifindex)) { dst_release(dst); dst = NULL; } --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -1179,7 +1179,7 @@ route_lookup: ndst = dst; }
- tdev = dst->dev; + tdev = dst_dev(dst);
if (tdev == dev) { DEV_STATS_INC(dev, collisions); @@ -1255,7 +1255,7 @@ route_lookup: /* Calculate max headroom for all the headers and adjust * needed_headroom if necessary. */ - max_headroom = LL_RESERVED_SPACE(dst->dev) + sizeof(struct ipv6hdr) + max_headroom = LL_RESERVED_SPACE(tdev) + sizeof(struct ipv6hdr) + dst->header_len + t->hlen; ip_tunnel_adj_headroom(dev, max_headroom);
--- a/net/ipv6/ip6_udp_tunnel.c +++ b/net/ipv6/ip6_udp_tunnel.c @@ -168,7 +168,7 @@ struct dst_entry *udp_tunnel6_dst_lookup netdev_dbg(dev, "no route to %pI6\n", &fl6.daddr); return ERR_PTR(-ENETUNREACH); } - if (dst->dev == dev) { /* is this necessary? */ + if (dst_dev(dst) == dev) { /* is this necessary? */ netdev_dbg(dev, "circular route to %pI6\n", &fl6.daddr); dst_release(dst); return ERR_PTR(-ELOOP); --- a/net/ipv6/ip6_vti.c +++ b/net/ipv6/ip6_vti.c @@ -497,7 +497,7 @@ vti6_xmit(struct sk_buff *skb, struct ne (const struct in6_addr *)&x->id.daddr)) goto tx_err_link_failure;
- tdev = dst->dev; + tdev = dst_dev(dst);
if (tdev == dev) { DEV_STATS_INC(dev, collisions); --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -473,6 +473,7 @@ void ndisc_send_skb(struct sk_buff *skb, { struct icmp6hdr *icmp6h = icmp6_hdr(skb); struct dst_entry *dst = skb_dst(skb); + struct net_device *dev; struct inet6_dev *idev; struct net *net; struct sock *sk; @@ -507,11 +508,12 @@ void ndisc_send_skb(struct sk_buff *skb,
ip6_nd_hdr(skb, saddr, daddr, READ_ONCE(inet6_sk(sk)->hop_limit), skb->len);
- idev = __in6_dev_get(dst->dev); + dev = dst_dev(dst); + idev = __in6_dev_get(dev); IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTREQUESTS);
err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, - net, sk, skb, NULL, dst->dev, + net, sk, skb, NULL, dev, dst_output); if (!err) { ICMP6MSGOUT_INC_STATS(net, idev, type); --- a/net/ipv6/netfilter/nf_dup_ipv6.c +++ b/net/ipv6/netfilter/nf_dup_ipv6.c @@ -38,7 +38,7 @@ static bool nf_dup_ipv6_route(struct net } skb_dst_drop(skb); skb_dst_set(skb, dst); - skb->dev = dst->dev; + skb->dev = dst_dev(dst); skb->protocol = htons(ETH_P_IPV6);
return true; --- a/net/ipv6/output_core.c +++ b/net/ipv6/output_core.c @@ -105,7 +105,7 @@ int ip6_dst_hoplimit(struct dst_entry *d { int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT); if (hoplimit == 0) { - struct net_device *dev = dst->dev; + struct net_device *dev = dst_dev(dst); struct inet6_dev *idev;
rcu_read_lock(); --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -228,13 +228,13 @@ static struct neighbour *ip6_dst_neigh_l const struct rt6_info *rt = dst_rt6_info(dst);
return ip6_neigh_lookup(rt6_nexthop(rt, &in6addr_any), - dst->dev, skb, daddr); + dst_dev(dst), skb, daddr); }
static void ip6_confirm_neigh(const struct dst_entry *dst, const void *daddr) { const struct rt6_info *rt = dst_rt6_info(dst); - struct net_device *dev = dst->dev; + struct net_device *dev = dst_dev(dst);
daddr = choose_neigh_daddr(rt6_nexthop(rt, &in6addr_any), NULL, daddr); if (!daddr) @@ -2945,7 +2945,7 @@ static void __ip6_rt_update_pmtu(struct
if (res.f6i->nh) { struct fib6_nh_match_arg arg = { - .dev = dst->dev, + .dev = dst_dev(dst), .gw = &rt6->rt6i_gateway, };
@@ -3240,7 +3240,7 @@ EXPORT_SYMBOL_GPL(ip6_sk_redirect);
static unsigned int ip6_default_advmss(const struct dst_entry *dst) { - struct net_device *dev = dst->dev; + struct net_device *dev = dst_dev(dst); unsigned int mtu = dst_mtu(dst); struct net *net;
@@ -4264,7 +4264,7 @@ static void rt6_do_redirect(struct dst_e
if (res.f6i->nh) { struct fib6_nh_match_arg arg = { - .dev = dst->dev, + .dev = dst_dev(dst), .gw = &rt->rt6i_gateway, };
@@ -4551,13 +4551,14 @@ int ipv6_route_ioctl(struct net *net, un static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes) { struct dst_entry *dst = skb_dst(skb); - struct net *net = dev_net(dst->dev); + struct net_device *dev = dst_dev(dst); + struct net *net = dev_net(dev); struct inet6_dev *idev; SKB_DR(reason); int type;
if (netif_is_l3_master(skb->dev) || - dst->dev == net->loopback_dev) + dev == net->loopback_dev) idev = __in6_dev_get_safely(dev_get_by_index_rcu(net, IP6CB(skb)->iif)); else idev = ip6_dst_idev(dst); @@ -5775,11 +5776,14 @@ static int rt6_fill_node(struct net *net * each as a nexthop within RTA_MULTIPATH. */ if (rt6) { + struct net_device *dev; + if (rt6_flags & RTF_GATEWAY && nla_put_in6_addr(skb, RTA_GATEWAY, &rt6->rt6i_gateway)) goto nla_put_failure;
- if (dst->dev && nla_put_u32(skb, RTA_OIF, dst->dev->ifindex)) + dev = dst_dev(dst); + if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex)) goto nla_put_failure;
if (dst->lwtstate && --- a/net/ipv6/rpl_iptunnel.c +++ b/net/ipv6/rpl_iptunnel.c @@ -242,7 +242,7 @@ static int rpl_output(struct net *net, s local_bh_enable(); }
- err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev)); + err = skb_cow_head(skb, LL_RESERVED_SPACE(dst_dev(dst))); if (unlikely(err)) goto drop; } @@ -297,7 +297,7 @@ static int rpl_input(struct sk_buff *skb local_bh_enable(); }
- err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev)); + err = skb_cow_head(skb, LL_RESERVED_SPACE(dst_dev(dst))); if (unlikely(err)) goto drop; } else { --- a/net/ipv6/seg6_iptunnel.c +++ b/net/ipv6/seg6_iptunnel.c @@ -128,7 +128,8 @@ static int __seg6_do_srh_encap(struct sk int proto, struct dst_entry *cache_dst) { struct dst_entry *dst = skb_dst(skb); - struct net *net = dev_net(dst->dev); + struct net_device *dev = dst_dev(dst); + struct net *net = dev_net(dev); struct ipv6hdr *hdr, *inner_hdr; struct ipv6_sr_hdr *isrh; int hdrlen, tot_len, err; @@ -181,7 +182,7 @@ static int __seg6_do_srh_encap(struct sk isrh->nexthdr = proto;
hdr->daddr = isrh->segments[isrh->first_segment]; - set_tun_src(net, dst->dev, &hdr->daddr, &hdr->saddr); + set_tun_src(net, dev, &hdr->daddr, &hdr->saddr);
#ifdef CONFIG_IPV6_SEG6_HMAC if (sr_has_hmac(isrh)) { @@ -212,7 +213,8 @@ static int seg6_do_srh_encap_red(struct { __u8 first_seg = osrh->first_segment; struct dst_entry *dst = skb_dst(skb); - struct net *net = dev_net(dst->dev); + struct net_device *dev = dst_dev(dst); + struct net *net = dev_net(dev); struct ipv6hdr *hdr, *inner_hdr; int hdrlen = ipv6_optlen(osrh); int red_tlv_offset, tlv_offset; @@ -270,7 +272,7 @@ static int seg6_do_srh_encap_red(struct if (skip_srh) { hdr->nexthdr = proto;
- set_tun_src(net, dst->dev, &hdr->daddr, &hdr->saddr); + set_tun_src(net, dev, &hdr->daddr, &hdr->saddr); goto out; }
@@ -306,7 +308,7 @@ static int seg6_do_srh_encap_red(struct
srcaddr: isrh->nexthdr = proto; - set_tun_src(net, dst->dev, &hdr->daddr, &hdr->saddr); + set_tun_src(net, dev, &hdr->daddr, &hdr->saddr);
#ifdef CONFIG_IPV6_SEG6_HMAC if (unlikely(!skip_srh && sr_has_hmac(isrh))) { @@ -507,7 +509,7 @@ static int seg6_input_core(struct net *n local_bh_enable(); }
- err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev)); + err = skb_cow_head(skb, LL_RESERVED_SPACE(dst_dev(dst))); if (unlikely(err)) goto drop; } else { @@ -518,7 +520,7 @@ static int seg6_input_core(struct net *n if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled)) return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, dev_net(skb->dev), NULL, skb, NULL, - skb_dst(skb)->dev, seg6_input_finish); + skb_dst_dev(skb), seg6_input_finish);
return seg6_input_finish(dev_net(skb->dev), NULL, skb); drop: @@ -593,7 +595,7 @@ static int seg6_output_core(struct net * local_bh_enable(); }
- err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev)); + err = skb_cow_head(skb, LL_RESERVED_SPACE(dst_dev(dst))); if (unlikely(err)) goto drop; } @@ -603,7 +605,7 @@ static int seg6_output_core(struct net *
if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled)) return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk, skb, - NULL, skb_dst(skb)->dev, dst_output); + NULL, dst_dev(dst), dst_output);
return dst_output(net, sk, skb); drop: --- a/net/ipv6/seg6_local.c +++ b/net/ipv6/seg6_local.c @@ -310,7 +310,7 @@ seg6_lookup_any_nexthop(struct sk_buff * if (!local_delivery) dev_flags |= IFF_LOOPBACK;
- if (dst && (dst->dev->flags & dev_flags) && !dst->error) { + if (dst && (dst_dev(dst)->flags & dev_flags) && !dst->error) { dst_release(dst); dst = NULL; }