From: Willem de Bruijn <will...@google.com>
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 <will...@google.com>
---
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 62508a2f9b21..d9034073138c 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -6380,8 +6380,8 @@ 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;
}
--
2.19.0.rc2.392.g5ba43deb5a-goog
