From: Eric Dumazet <edumazet@google.com>
To: "David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>,
Kuniyuki Iwashima <kuniyu@google.com>,
Willem de Bruijn <willemb@google.com>,
David Ahern <dsahern@kernel.org>,
netdev@vger.kernel.org, eric.dumazet@gmail.com,
Eric Dumazet <edumazet@google.com>
Subject: [PATCH v2 net 1/5] icmp: prevent possible overflow in icmp_global_allow()
Date: Mon, 16 Feb 2026 14:28:28 +0000 [thread overview]
Message-ID: <20260216142832.3834174-2-edumazet@google.com> (raw)
In-Reply-To: <20260216142832.3834174-1-edumazet@google.com>
Following expression can overflow
if sysctl_icmp_msgs_per_sec is big enough.
sysctl_icmp_msgs_per_sec * delta / HZ;
Fixes: 4cdf507d5452 ("icmp: add a global rate limitation")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
---
net/ipv4/icmp.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index e216b6df633123ed475e28907d788db6bfb42115..eff8487c0aba8df0d1e515b9ac6ff7f9ac1de436 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -250,7 +250,8 @@ bool icmp_global_allow(struct net *net)
if (delta < HZ / 50)
return false;
- incr = READ_ONCE(net->ipv4.sysctl_icmp_msgs_per_sec) * delta / HZ;
+ incr = READ_ONCE(net->ipv4.sysctl_icmp_msgs_per_sec);
+ incr = div_u64((u64)incr * delta, HZ);
if (!incr)
return false;
--
2.53.0.310.g728cabbaf7-goog
next prev parent reply other threads:[~2026-02-16 14:28 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-16 14:28 [PATCH v2 net 0/5] icmp: better deal with DDOS Eric Dumazet
2026-02-16 14:28 ` Eric Dumazet [this message]
2026-02-16 14:28 ` [PATCH v2 net 2/5] inet: move icmp_global_{credit,stamp} to a separate cache line Eric Dumazet
2026-02-16 14:28 ` [PATCH v2 net 3/5] ipv6: icmp: remove obsolete code in icmpv6_xrlim_allow() Eric Dumazet
2026-02-16 14:28 ` [PATCH v2 net 4/5] ipv4: icmp: icmpv4_xrlim_allow() optimization if net.ipv4.icmp_ratelimit is zero Eric Dumazet
2026-02-16 14:28 ` [PATCH v2 net 5/5] ipv6: icmp: icmpv6_xrlim_allow() optimization if net.ipv6.icmp.ratelimit " Eric Dumazet
2026-02-19 1:10 ` [PATCH v2 net 0/5] icmp: better deal with DDOS patchwork-bot+netdevbpf
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