From 0297c1c2eadb5bd996a873b87597af3b91c0d4ba Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Sun, 9 Sep 2018 19:12:12 -0400 Subject: [PATCH] tcp: rate limit synflood warnings further Convert pr_info to net_info_ratelimited to limit the total number of synflood warnings. Commit 946cedccbd73 ("tcp: Change possible SYN flooding messages") rate limits synflood warnings to one per listener. Workloads that open many listener sockets can still see a high rate of log messages. Syzkaller is one frequent example. Signed-off-by: Willem de Bruijn Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 4c2dd9f863f7..4cf2f7bb2802 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -6367,8 +6367,8 @@ static bool tcp_syn_flood_action(const struct sock *sk, if (!queue->synflood_warned && net->ipv4.sysctl_tcp_syncookies != 2 && xchg(&queue->synflood_warned, 1) == 0) - pr_info("%s: Possible SYN flooding on port %d. %s. Check SNMP counters.\n", - proto, ntohs(tcp_hdr(skb)->dest), msg); + net_info_ratelimited("%s: Possible SYN flooding on port %d. %s. Check SNMP counters.\n", + proto, ntohs(tcp_hdr(skb)->dest), msg); return want_cookie; } -- GitLab