From: Ido Schimmel <idosch@nvidia.com>
To: Eric Dumazet <edumazet@google.com>
Cc: "David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Simon Horman <horms@kernel.org>, David Ahern <dsahern@kernel.org>,
netdev@vger.kernel.org, eric.dumazet@gmail.com
Subject: Re: [PATCH net] net: do not send ICMP/NDISC Redirects when peer allocation fails
Date: Sun, 26 Jul 2026 17:06:01 +0300 [thread overview]
Message-ID: <20260726140601.GA388109@shredder> (raw)
In-Reply-To: <20260724072901.1633601-1-edumazet@google.com>
On Fri, Jul 24, 2026 at 07:29:01AM +0000, Eric Dumazet wrote:
> When inet_getpeer_v4() or inet_getpeer_v6() fails to allocate a peer entry
> under memory pressure or tree size caps, redirect handlers previously fell
> back to sending un-rate-limited ICMP/NDISC Redirect messages.
>
> In IPv4, ip_rt_send_redirect() called icmp_send() directly when peer == NULL.
> In IPv6, ip6_forward() and ndisc_send_redirect() passed a NULL peer into
> inet_peer_xrlim_allow(), which returned true when peer == NULL.
>
> Because ICMP/NDISC Redirects are not part of the default global rate limit
> mask (sysctl_icmp_ratemask), sending redirects when peer == NULL creates
> an un-rate-limited ICMP packet storm.
>
> Fix this by failing closed in ip_rt_send_redirect(), ip6_forward(), and
> ndisc_send_redirect() when peer is NULL.
>
> Fixes: 92d868292634 ("inetpeer: Move ICMP rate limiting state into inet_peer entries.")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
prev parent reply other threads:[~2026-07-26 14:06 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-24 7:29 [PATCH net] net: do not send ICMP/NDISC Redirects when peer allocation fails Eric Dumazet
2026-07-24 13:42 ` Jakub Kicinski
2026-07-24 14:15 ` Eric Dumazet
2026-07-24 14:20 ` Jakub Kicinski
2026-07-26 14:06 ` Ido Schimmel [this message]
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