[PATCH net-next 7/8] ipv6: exthdrs: annotate data-race over multiple sysctl
From: Eric Dumazet <edumazet@google.com>
Date: 2026-01-15 09:41:56
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
Following four sysctls can change under us, add missing READ_ONCE(). - ipv6.sysctl.max_dst_opts_len - ipv6.sysctl.max_dst_opts_cnt - ipv6.sysctl.max_hbh_opts_len - ipv6.sysctl.max_hbh_opts_cnt Signed-off-by: Eric Dumazet <edumazet@google.com> --- net/ipv6/exthdrs.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index a23eb8734e151dac46a2d03d15de10ce6e45af54..54088fa0c09d068d35779e3cafd721cd24e00ea8 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c@@ -314,7 +314,7 @@ static int ipv6_destopt_rcv(struct sk_buff *skb) } extlen = (skb_transport_header(skb)[1] + 1) << 3; - if (extlen > net->ipv6.sysctl.max_dst_opts_len) + if (extlen > READ_ONCE(net->ipv6.sysctl.max_dst_opts_len)) goto fail_and_free; opt->lastopt = opt->dst1 = skb_network_header_len(skb);
@@ -322,7 +322,8 @@ static int ipv6_destopt_rcv(struct sk_buff *skb) dstbuf = opt->dst1; #endif - if (ip6_parse_tlv(false, skb, net->ipv6.sysctl.max_dst_opts_cnt)) { + if (ip6_parse_tlv(false, skb, + READ_ONCE(net->ipv6.sysctl.max_dst_opts_cnt))) { skb->transport_header += extlen; opt = IP6CB(skb); #if IS_ENABLED(CONFIG_IPV6_MIP6)
@@ -1049,11 +1050,12 @@ int ipv6_parse_hopopts(struct sk_buff *skb) } extlen = (skb_transport_header(skb)[1] + 1) << 3; - if (extlen > net->ipv6.sysctl.max_hbh_opts_len) + if (extlen > READ_ONCE(net->ipv6.sysctl.max_hbh_opts_len)) goto fail_and_free; opt->flags |= IP6SKB_HOPBYHOP; - if (ip6_parse_tlv(true, skb, net->ipv6.sysctl.max_hbh_opts_cnt)) { + if (ip6_parse_tlv(true, skb, + READ_ONCE(net->ipv6.sysctl.max_hbh_opts_cnt))) { skb->transport_header += extlen; opt = IP6CB(skb); opt->nhoff = sizeof(struct ipv6hdr);
--
2.52.0.457.g6b5491de43-goog