6.12-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
[ Upstream commit 34aef2b0ce3aa4eb4ef2e1f5cad3738d527032f5 ]
icmp6_send() must acquire rcu_read_lock() sooner to ensure the dev_net() call done from a safe context.
Other ICMPv6 uses of dev_net() seem safe, change them to dev_net_rcu() to get LOCKDEP support to catch bugs.
Fixes: 9a43b709a230 ("[NETNS][IPV6] icmp6 - make icmpv6_socket per namespace") Signed-off-by: Eric Dumazet edumazet@google.com Link: https://patch.msgid.link/20250205155120.1676781-12-edumazet@google.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv6/icmp.c | 42 +++++++++++++++++++++++------------------- 1 file changed, 23 insertions(+), 19 deletions(-)
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index a6984a29fdb9d..4d14ab7f7e99f 100644 --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -76,7 +76,7 @@ static int icmpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, { /* icmpv6_notify checks 8 bytes can be pulled, icmp6hdr is 8 bytes */ struct icmp6hdr *icmp6 = (struct icmp6hdr *) (skb->data + offset); - struct net *net = dev_net(skb->dev); + struct net *net = dev_net_rcu(skb->dev);
if (type == ICMPV6_PKT_TOOBIG) ip6_update_pmtu(skb, net, info, skb->dev->ifindex, 0, sock_net_uid(net, NULL)); @@ -473,7 +473,10 @@ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
if (!skb->dev) return; - net = dev_net(skb->dev); + + rcu_read_lock(); + + net = dev_net_rcu(skb->dev); mark = IP6_REPLY_MARK(net, skb->mark); /* * Make sure we respect the rules @@ -496,7 +499,7 @@ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, !(type == ICMPV6_PARAMPROB && code == ICMPV6_UNK_OPTION && (opt_unrec(skb, info)))) - return; + goto out;
saddr = NULL; } @@ -526,7 +529,7 @@ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) { net_dbg_ratelimited("icmp6_send: addr_any/mcast source [%pI6c > %pI6c]\n", &hdr->saddr, &hdr->daddr); - return; + goto out; }
/* @@ -535,7 +538,7 @@ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, if (is_ineligible(skb)) { net_dbg_ratelimited("icmp6_send: no reply to icmp error [%pI6c > %pI6c]\n", &hdr->saddr, &hdr->daddr); - return; + goto out; }
/* Needed by both icmpv6_global_allow and icmpv6_xmit_lock */ @@ -582,7 +585,7 @@ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, np = inet6_sk(sk);
if (!icmpv6_xrlim_allow(sk, type, &fl6, apply_ratelimit)) - goto out; + goto out_unlock;
tmp_hdr.icmp6_type = type; tmp_hdr.icmp6_code = code; @@ -600,7 +603,7 @@ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
dst = icmpv6_route_lookup(net, skb, sk, &fl6); if (IS_ERR(dst)) - goto out; + goto out_unlock;
ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
@@ -616,7 +619,6 @@ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, goto out_dst_release; }
- rcu_read_lock(); idev = __in6_dev_get(skb->dev);
if (ip6_append_data(sk, icmpv6_getfrag, &msg, @@ -630,13 +632,15 @@ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, len + sizeof(struct icmp6hdr)); } - rcu_read_unlock(); + out_dst_release: dst_release(dst); -out: +out_unlock: icmpv6_xmit_unlock(sk); out_bh_enable: local_bh_enable(); +out: + rcu_read_unlock(); } EXPORT_SYMBOL(icmp6_send);
@@ -679,8 +683,8 @@ int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type, skb_pull(skb2, nhs); skb_reset_network_header(skb2);
- rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0, - skb, 0); + rt = rt6_lookup(dev_net_rcu(skb->dev), &ipv6_hdr(skb2)->saddr, + NULL, 0, skb, 0);
if (rt && rt->dst.dev) skb2->dev = rt->dst.dev; @@ -717,7 +721,7 @@ EXPORT_SYMBOL(ip6_err_gen_icmpv6_unreach);
static enum skb_drop_reason icmpv6_echo_reply(struct sk_buff *skb) { - struct net *net = dev_net(skb->dev); + struct net *net = dev_net_rcu(skb->dev); struct sock *sk; struct inet6_dev *idev; struct ipv6_pinfo *np; @@ -832,7 +836,7 @@ enum skb_drop_reason icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info) { struct inet6_skb_parm *opt = IP6CB(skb); - struct net *net = dev_net(skb->dev); + struct net *net = dev_net_rcu(skb->dev); const struct inet6_protocol *ipprot; enum skb_drop_reason reason; int inner_offset; @@ -889,7 +893,7 @@ enum skb_drop_reason icmpv6_notify(struct sk_buff *skb, u8 type, static int icmpv6_rcv(struct sk_buff *skb) { enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; - struct net *net = dev_net(skb->dev); + struct net *net = dev_net_rcu(skb->dev); struct net_device *dev = icmp6_dev(skb); struct inet6_dev *idev = __in6_dev_get(dev); const struct in6_addr *saddr, *daddr; @@ -921,7 +925,7 @@ static int icmpv6_rcv(struct sk_buff *skb) skb_set_network_header(skb, nh); }
- __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INMSGS); + __ICMP6_INC_STATS(dev_net_rcu(dev), idev, ICMP6_MIB_INMSGS);
saddr = &ipv6_hdr(skb)->saddr; daddr = &ipv6_hdr(skb)->daddr; @@ -939,7 +943,7 @@ static int icmpv6_rcv(struct sk_buff *skb)
type = hdr->icmp6_type;
- ICMP6MSGIN_INC_STATS(dev_net(dev), idev, type); + ICMP6MSGIN_INC_STATS(dev_net_rcu(dev), idev, type);
switch (type) { case ICMPV6_ECHO_REQUEST: @@ -1034,9 +1038,9 @@ static int icmpv6_rcv(struct sk_buff *skb)
csum_error: reason = SKB_DROP_REASON_ICMP_CSUM; - __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS); + __ICMP6_INC_STATS(dev_net_rcu(dev), idev, ICMP6_MIB_CSUMERRORS); discard_it: - __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INERRORS); + __ICMP6_INC_STATS(dev_net_rcu(dev), idev, ICMP6_MIB_INERRORS); drop_no_count: kfree_skb_reason(skb, reason); return 0;